Well, it's a complicated question, because there are several different cases to consider:

The tire is simply flat because the air leaked out slowly.
There is a hole in the tire due to a nail or thorn or shard of glass.
There is a large hole or cut in the tire.

Slow leak
The first thing you need is a pump.  Sometimes (but not usually) you can pump up the flat tire and it will hold air for 30 minutes or so, allowing you to ride home or at least letting you ride for several minutes before you stop and pump it up again.
Hole
The normal case is that there is no obvious damage to the tire, but when you try to pump it up it doesn't hold air.  Then you need the pump, "tire irons", and either a patch kit or a spare inner tube.  You may also need wrenches to loosen your wheel, if it does not have a "quick release".
The procedure is to remove the wheel from the bike, then use the tire "irons" (most of which now are actually made of plastic) to pry one side of the tire off the rim.  (This procedure is a bit more complicated than that statement -- it takes practice to do without damaging the inner tube further, and an entire article could be written on this topic alone.)  Then remove the inner tube from inside the tire.
At this point, even if you have a spare tube, it's wise to attempt to find the hole in the old tube and then look at that spot inside the tire to see if there's still a nail or thorn sticking through.
Using spare tube
Then, if you have a spare tube, you install it in place of the bad one (pump a little air into it first to make it round), use the tire irons to get the tire back on the rim, and then pump up the tire.  I like to pump it up once, deflate it, and then pump again, to help position the tube and "seat" the tire on the rim.  Once it's pumped up examine the wheel for any obvious lumps (indicating the tube may be twisted inside) and to see that the tire is evenly installed on the rim.
Using patch kit
If you don't have a spare tube (but DO have a patch kit), you should attach your pump to the old one and try to pump it up.  Air will exit the leak, and you can hear/feel the air escaping.  Mark the hole somehow -- a pencil, a ballpoint pen, or a piece of chalk will work.  But note that you will be cleaning the area around the hole, so make marks well away from the hole that you can line up to locate the hole after cleaning.
Read the instructions that come with the patch kit.  Usually you clean around the hole using the sandpaper that comes in the patch kit, spread glue (also in the kit) around the hole and let it mostly dry, then attach the patch over the hole.  Then it's usually wise to wait 5-10 minutes before inflating (though during that period several times pressing the patch tightly against the tube).  It's probably a good idea to then inflate the tube a bit to be sure that there are no more holes and that you covered the one hole correctly.
I like to spread some chalk powder or simply a bit of dust from the ground over the patch area to keep it from sticking to the inside of the tire.
Reinstall the tube the same as with the spare tube.
Large hole
If you discover that you have a large hole or cut in the tire then it's necessary to use some sort of "boot" inside the tire, to keep the new/repaired tube from bulging through the hole.  Of course, some holes are simply too large for this to work, but usually it's worth a try regardless of how big the hole is.
For a boot you want a piece of thin but relatively stiff/strong material.  Special strips of reenforced rubber are sold at bike shops for this, or you can cut a section from the side of an old tire.  A popular technique in the US is to use a folded-up dollar bill -- the paper that the US dollar is made from is quite durable and stiff, and, if a relatively new bill is folded into four layers it works quite well for small or medium holes.
To use the boot you get the tube repaired and installed, and just before you put the tire back on the rim you work the boot in between the tube and tire so that it covers the hole.  Then put the tire back on the rim and inflate.


Can I use normal grease for a car on the surface of carbon bike?

From Sheldon Brown:

Grease lubrication is commonly used on all ball bearings. Good mechanics also use grease (or oil) on the threads of most threaded fittings and fasteners, and also inside the steerer (to keep the stem from becoming stuck) and the seat tube (to keep the seatpost from becoming stuck.)
There are a great many different greases on the market with different special features, mainly for automotive applications. For bicycle use, almost any grease is adequate, since the loads and temperatures are generally low.

Seems to me like the answer is yes, although to be safe why don't you invest in some Finish Line Teflon Grease - one tube will last you for years. From the Finish Line website:

Q. Are Finish Line products safe for use on Carbon Fiber Frames and Parts?
A. Yes. All of our products are safe to use on carbon fiber bike parts; our three degreasers, four lubes, our polish, grease, etc are all safe to use on and around carbon fiber bike parts. The exception is our DOT Brake Fluid – you don’t want to get DOT fluid on any painted or finished surface because it’ll attack the paint / finish.


Alternative Firmware for Garmin Edge 500

Garmin do not publish the firmware or provide support for community modifications, and actually seem to be killing off the one community feature they had allowed (the ability to use non Garmin maps) in some areas.

My advice - buy another device for the other bike, or just accept that navigating through 5 menus isn't really that bad:-)


It sounds like your brake pads are contaminated with detergent or petroleum (oil) products. If so, you need to replace them.

This is a common problem, which can be solved by washing the brake rotors with IPA, and replacing your brake pads.  It sometimes happens that a pad will get contaminated by chain lube or other common bike lubricants during the washing process of a bike service, and should be no big deal to fix.

As this is something that any shop worth 2 cents should know, they are either incompetent, or dishonest with you.


Why does my front mountain bike wheel sway left and right slightly?

Two reasons why you may be seeing the wheel move from side to side, and each has a fix that involves tightening something.

The first is that the rim is out of true, so when you spin the wheel the rim and tire appear to move side-to-side relative to a fixed point such as the fork or rim brakes. What your mechanic would have done in this case is adjusted the tension in left and right hand spokes to make the rim true again. YOu may have had a single spoke that came loose and needed re-tensioning. If you are still seeing some apparent movement when you spin the wheel, or you have rim brakes and the rim hits the pad at some point the mechanic may simply have not done a particularly good job. You can ask for them to improve the wheel or go to a different mechanic.

The other possibility is that the hub bearings are loose and the whole wheel is wobbling on the axle. This is easy to diagnose: grab the tire and try to move the wheel side-to-side, if you can feel the wheel rocking slightly the bearings are possibly loose. Some hubs have adjustable bearings and you mechanic may have tightened them. Again you can return to your mechanic or use a different one.


Why are foot-long pedals not widely used?

I'd wager the two biggest reasons you don't see foot-sized pedals are the increased rotational weight, and the difficulty you would have catching the pedal with your foot before it struck the ground or the front tire. I'm sure someone tried this once and promptly scrapped the idea after the foot-sized pedal struck something.

Pedals need to be stiff and durable, which is fine. But if pedals had to be stiff and durable and large, they would probably end up being heavy, so it makes sense that most pedals you see are small and compact. Shoes already do a great job of interfacing with and conforming to your feet, and it's easy enough to make the sole stiff with plastic, fiberglass, and carbon fiber. All of these factors combined explain why we have small pedals.


Strava has a heatmap function you can enable on their route planner.  This will show the more frequently used streets and will vary intensity of color based on popularity.
http://www.strava.com/routes/
Garmin Connect also has a heat map functionality built in to their route planner.
http://connect.garmin.com/course/create
The garmin maps seem to be more effective in heavily used areas like city center and heavily trafficked trails, while strava seems to be a bit better at showing a bit more detail in both city and rural areas.
May also want to check out Race Shape's heat map, which seems to be a worldwide bike based heat map. Race shape pulls data from strava and ridewithgps.com to create these heat maps. http://raceshape.com/heatmap/
(Strava has taken over Raceshape and incorporated it in their premium product.)


Is it difficult for one person to ride a tandem bike?

I have a 1990 steel racing tandem, and sadly it gets more miles solo than with a stoker.

The main differences between tandems and solo bikes apply when riding a tandem on your own (rear wheel cuts corners more, you can't bunny hop)  but points to note:

Cars may not see the rear of your bike, and may not anticipate the extra space required when pulling up or allowing room to turn.
Steering is a bit odd - it may be unique to mine, but if the solocaptain doesn't commit to a corner with enough lean, the bike tries to stand up straight and go straight.
Braking - its still possible to raise the back wheel clear off the ground when doing an aggressive brake with just a captain.  And the stoker's bars may get in the way of your backside if you lean backwards.
Drag brake is less effective with no stoker.  So big descents you have to ride more like a solo bike.
You may get heckled with "Your passenger fell off!" so have a witty retort like "Bugger - so that's why she stopped nagging!" or "Damn I thought we were going slower than normal!"

Speed is generally not an issue - I've topped 40 km/h solo on my tandem, and the previous owner exceeded 70 km/h on it on a race, with two riders.


Are there any permanent solutions for holes smaller than 1cm on outer tyre?

You may be surprised how long your paper patch lasts. I've used dollar bills, empty energy gel packs and they have lasted quite a long time, but now carry Park Tool Tire Boots.

They have an adhesive and attach to the inside of your tire and stay put, even if you get another flat and have to change tubes. I've found that the money or paper solution will move or fall out of place without the pressure of the tube to hold it in place.

You should be able find the Park Tool Tire Boots at any local bike shop, but here is a link to Amazon: Park Tool TB-2 Emergency Tire Boot


This is achievable, but you're using a big hammer to fix a potentially small problem.

If your wheel has a Quick Release axle like pictured on the right side here

Simply removing the QR Skewer and slapping two nuts on the outside is a recipe for disaster.  There is not enough thread going outside the fork's dropouts to hold a nut.  There's 100mm (4 inches) of axle inside the wheel, and a QR only lets 2-3mm (not a lot) poke out either side.  You need at least as many threads out each side as there are threads in your new wheel nuts.

Another comparison

So you need a complete new front axle, 2x cone nuts, and 2x wheel nuts for the outside.  Its worth replacing the bearings at this time too, because they're cheap and may as well.

There are some slightly-custom tools needed too - picture shows a pair of thin cone spanners, which are only about 2mm thick.  A normal spanner won't fit on the cone nut flats to hold it while adjusting the bearings.

If your axle looks like this then its a Through Axle ("thru axle") and you're on a fairly modern bike.  Reverting to nutted wheel axle will require adapters that are custom to your frame/through axle design, and there are too many variations to explain here.


Why are some leather saddles laced at the bottom and should I do this to mine?

As a leather saddle wears out, it tends to sink and become softer in the middle while splaying out around the edges. This, naturally, makes the saddle uncomfortable and uneven. Lacing a saddle is a way to revive it and return it to its natural shape, or at least something close. You should lace your saddle if you find that it has become too soft.

And incidentally, many people punch holes in their leather saddles for this very purpose if the saddle didn't come with them.


Indoor cyclist keeps popping out of clips

On Shimano SPD pedals, you can sometimes adjust the tension for how tightly they clip in (likely via a hex bolt). If the tension is too low, your feet will be too easy to pop out, whereas if its too high, you won't easily be able to get out (which isn't a problem on an indoor cycling setup). Try playing with this setting to see if you stay clipped in (turning the bolt clockwise should increase the tension).

Also, there are two types of cleats  available -- single release (Shimano SH-51) which only release by turning your heel out and multi-release (Shimano SH-56) which release by turning in any direction. It shouldn't matter which one you use for indoor cycling (SH-56 is probably preferable for most people) but SH-51 might be an option if you're having trouble with SH-56.

If you can't get the tension to adjust and swapping the cleats doesn't work (if you're using SH-56), normally indoor cycling bikes have toe clips available as well. You may want to use those. And work on your form.


What is the next step in teaching my child to ride?

I think that, besides having fun - which is of utmost importance with kids otherwise they give up and choose to do something that is more fun and less distressful -, after they learn to keep balance and speed up, I'd say the next things must learn are to brake properly and to control their trajectory.

That said, one of the most exciting things to do, in my humble opinion, is to play tag (chasing game), or "follow the leader", in a park, taking turns on who is the leader.

When you are the leader (of course, not going too fast), she has to chase you and so she learns to do quick turns, brake, and change directions on demand (reactive).

When she is the leader, she develops her ability to read her surroundings and form trajectory-planning strategies in her mind (proactive).

Motor control resides in the cerebellum, and it must be automated by exhausitve repetition until it becomes automatic. There's no better way do do it than by playing and having fun, specially if it involves bicycle riding skills. It literally "grows in you". (I think that's why people say that no one ever forgets how to ride a bike).

Hope this helps


Correct inflation pressure for old road bike

I can't see your specific rims from here, but plenty of bikes back in the 70s and 80s had rims that width capable of handling 90-110 PSI.

And I definitely wouldn't run a 1-1/8" tire at 65 PSI.  I'd imagine that the rims, if designed for tires that narrow, should be able to handle 80 PSI or so.


I think I chose the wrong road bike size

Almost all road bikes have your torso leaning forward to some degree, meaning you have to hold your head up constantly. If you've never ridden a true road bike before, you've probably never had to do that. What's the longest ride you've done on a road bike before this two-hour ride?

Since you didn't mention your hands or arms hurting, you're probably not leaning too far forward.  Leaning forward (to get lower and more aerodynamic) can put more weight on your hands and can make your hands, arms, and/or shoulders hurt or go numb after a while, especially if you're not used to doing that.

But since you rode for 2 hours before things started hurting, your bicycle's size probably isn't too far from being correct.

So your sore neck is probably just from doing something for two hours that you're not used to.  There's a good chance you just need to ride more and get used to holding your head up.

As you ride more, you may find other fit issues.  You may have to get a completely different saddle, and it might take you three or four different attempts before you find a saddle you can ride without discomfort after some period of time.  You may find your shoes and/or pedal combination starts making your feet hurt or gives you hot spots (you'll know what a "hot spot" is and why it's called that if/when you get one....).  You may find certain brands of shorts have padding that rubs your nether regions raw.  As already noted, you might have your hands go numb after a while.  Welcome to cycling - that's all a part of it.

But it's important to note that you apparently had NONE of those issues in a two-hour ride, and you seemingly haven't ridden your new road bike for that long ever before.  So you're really doing pretty well, and in my opinion you probably don't have to change much, unless you've left something out of your question.

At least not yet...


Cable pull, indexing of Shimano's IGH vs. deraileur

Whatever you may read this CAN'T work properly simply because the gaps between each of the shifts are different on the Shimano Alfine SG-S700, there are THREE different gaps. The only shifters not made by Shimano to operate this hub properly are:

Jtek 11 Speed Bar End Shifter

and:

11 Speed Microshift Inter11 STI Levers


Depends how they've been stored.  If they were inside a garage or otherwise dry, then that's a lot less work.  If they were outside or damp, everything will be that much closer to EOL.

Gear changes and brakes: if there's been moisture in the cables then they can suffer but housings and inner wires can be replaced.

Tyres and tubes can degrade in heat.  Oils and greases will thicken and congeal so an all-round service of bearings can be in order.

Finally, why were they unused for a long time?  Was there a fault that was too hard to fix at the time?   Look for function.

On the other side, sometimes a good wash, and a lick of paint can make an old bike appear very much nicer too.


Why won't tires go on my Velocity A23 rims?

From some rather small experience I had with the problems you describe, I could give you these advices:

The first time you install a new (never used) tire is always the worst. Every tire gets a bit more "soft" to install after it's used a bit;
When you are inserting the "last bit" of tire bead, you have to be sure all the rest of the bead is centered in the rim, so that it may sink in the deepest part of the rim and release some bead for you to use the levers and put it in.
It's VERY important you pay attention to the position of the valve. It should never be opposite (180°) from the "last bit" of tire you are installing, otherwise the opposite side of the bead will not be deeply centered in the rim;
Levers should be thin. That means they must be of a very strong material, preferrably engineering plastic. I use Schwalbes (blue ones) and they are very good. Some other levers I have sometimes don't work, in these cases only the Schwalbes do, but there may be other good brands around.

At last, it's not impossible that your rim and your tire (at least the particular ones you have with you) are incompatible with each other. I would recommend you try to install the same tire in another rim, and another tire in the same rim, to check where the problem is, before asking for replacement of a part that is actually OK.

Hope this helps!


Re-learning how to corner aggressively at speed after bad experiences

I'm only posting this as an answer because it seemed long to comment.

But i would run some drills maybe once a week or whenever your free time allows. Go to a sports store and get some little multi sport cones, or use beer cans or toilet paper rolls or what ever else you have that won't hurt you or the bike if you run it over or fall on it.

Two drills that may help is a large slalom where you need to tightly weave back and forth. The other being a large circle.

Start with ample room where it is almost too easy, then as your confidence and speed increases, decrease the size of the shape or row, there by increasing the angle and lean that you need to use.

You could even go as far to set up a small sprint course either in grass or a parking lot depending on how you feel, and start tracking you time. That way your not racing anyone but yourself and your own head.

It may take awhile to build confidence but repetition is key, after a while that fear should slowly start to shrink. Likely you have some degree of PTSD from the event, some may think it's silly but its very real. I was in a head on 60mph collision (in a car not a bike) about 6 months ago, and unfortunately have to drive on that same 2 lane strip everyday to work, and still i get anxiety going through there, it's a 2 lane underpass, old road so it's narrow, with guard rails on either side so there is no where to go. Guy came into our lane and there was nothing we could do but wait to get hit. Point is, it gets better it just takes time and repetition.

I have also found it helped my cornering a lot to concentrate on my position relative to the bottom bracket, sounds goofy but consciously being aware of my bad form and working on it with similar drills helped me gain a lot of confidence, i had similar issues when i switch from a 2.35" mountain bike to a road bike, just didn't feel right.


Have you tried holding your tool like this:

I have just discovered it (instead of the classical "one tool per hand" technique) and it helped a lot.


Aluminium rims should give superior braking performance, as mentioned in this answer (Steel vs. Aluminum Wheels) and this blog (steel vs. aluminum wheels).

Check out the shape of the rims and how the brake blocks make contact. If the brake blocks are not in full contact then you will need to adjust them. See also @Batman's suggestion. That could involve further vertical adjustment of the blocks. Make sure the blocks are adjusted to be as close to the rim as possible without touching when the brakes are not applied, so the maximum braking effort can be applied.

Also check whether the calipers are moving as the pressure is applied (avoid riding the bike for this, if you can, because of the obvious danger). Because of the better grip the blocks get on the aluminium rims, it could be the old calipers are not rigid enough for the new job required of them.

If further adjustment and gentle riding does not rapidly improve the situation, invest in new brake blocks. After that, welcome to the expensive world of upgrades: new brakes, new cables, new ...).


Chain slipping on brand new bike, bike shop is stumped

The problem turned out to be the crank assembly. Apparently the chain ring offset on the original crank was wrong. The replacement that Shimano sent (having been given the bike year/make/model/groupset info etc) was a totally different offset than the one Kona shipped with the bike. The new crank resolved the chain slipping problem.
I don't know who messed up here. The bike shop thinks Kona shipped the bike with the wrong hardware, possibly on just my bike or potentially some set of the 2020 Lava Domes. Kona certainly didn't take responsibility originally though. Regardless, the issue was resolved by putting the right parts on the bike, thanks to Shimano. Thank you everyone for your responses and suggestions.


How often should hydraulic disk brakes need bleeding?

If the brake response gets mushy, also check the brake pads. Personal experience: I saw no need in bleeding the brakes before changing the brake fluid (on a DOT system). Maybe your system is not sufficiently sealed?

The need to exchange the fluid depends on the type that is used in your brakes. And this should be self-evident: Do not, under any circumstances, change the type of fluid used in your brake! It will most certainly degrade the gaskets.

DOT

If your brakes use DOT (classified by the US Department of Transportation) brake fluid, i.e. "DOT 5.1", the fluid should be exchanged every 1-2 years [1]. With time, the fluid absorbs water, affecting its compressibility. This is by design, since non-absorbed water would affect the compressibility even more.

Mineral Oil

Mineral oil, however, does not need to be changed so regularly. Unless you open the system, the oil stays good for up to 6-7 years [2].

[1] Bosch Automotive Handbook, 7th Edition, ISBN 978-0-7680-1953-7
[2] http://www.magura.com/de/produkte/scheibenbremsen-2012/prod/mt2/info/faq.html


You're right - something has to change.  11 will not work properly with 10, and vise versa.
Ideally, you're going to have to standarise on 11 speed on both bikes.  That means new shifter, chain, cassette, and maybe rear derailleur.  This is probably the most expensive solution, though you can sell off the 10 speed parts to recoup some funds.
Your other option is to move your 10 speed cassette to the trainer for your bike, (or have a second 10 speed cassette spare)  and swap an 11 speed cassette onto trainer for the other bike.  THis is faddly and will add wear and inconvenience.
Your third option is to find a third bike and leave it on the trainer permanently to share, though that bike is unlikely to fit both of you.   Or buy a second trainer and configure for 10 speed (though this is a ludicrously expensive solution)


Do the cups of headsets with cartridge bearings wear out?

The bearing races themselves get replaced, but what can happen is the races becoming loose in the frame. I can't imagine that happening just through wear, though, you'd have to pull and replace the bearing races hundreds of times. Normally that is the result of either a crash deforming the races, or the bearing not being quite square when someone hammers it into the frame. To avoid the latter use a proper bearing press or fake it with a length of threaded rod. In general, any time you find yourself wanting to use a hammer on a bike you're doing something wrong.


0.2mm on seatpost clamp will make no difference!
The tolerence is small maybe 1-2mm. a 0.2mm difference is pretty much how far the clamp moves when you tighten the binder! maybe even more.
Youll see how far it moves when you take the binder off the frame and tighten it a little. the clamp goes smaller basically clamping down. so in practice it clamps the seat tube down onto the seatpost tightening all in its place. long explanation, I know but thats the just of it.


Upgrading crankset on mountain bike - what are my options

Probably you have already figured out an answer from the given comments, but here is my answer.

I have a bike with a very similar set up. It is an old MTB with rigid fork that I turned into a fast commuter. Like you, the first thing I did was changing the tires to a pair of "1.3 Continental Sport Contact. Later, I changed the crankset and the cassette, which happens to be the same as yours.

I am using a triple crankset Shimano FC-M171 (48-38-28). You can buy it new for around 20€.

About the required adaptations, I would say:

Don't change the front derailleur, probably yours will have enough room. You will have to move it up a bit. A rule of thumb is to leave 2 mm clearance between the bottom of the outer cage plate and the teeth of the large chain wheel, but you'll have to try to find the best fit. Sheldon Brown has a nice guide about derailleur adjustment.
Replace the chain, which is advisable when changing the crankset and/or the cassette (they all wear out at the same time). Also, the new crankset will require a longer chain. I'd say something between 112 and 118 links. It is preferable to buy it longer and then remove the links in excess.
Probably you will need a wider bottom bracket (larger axle length). This is a requirement for the new crankset, otherwise it may happen that the smaller chainring will touch the frame. E.g., in the case of the FC-M171, it requires an axle length of 122 mm. The diameter of the bottom bracket will be the same of your current one. A low-end Shimano squared bottom bracket (sealed) costs around 10€ new.

I must add that for me this amplitude is great for every occasion, I can climb reasonably well and I can also reach 50 kph with a reasonable cadence (not sure, probably something between 80 and 110 rpm).

Go for it.


I've had something similar on my Topeak Road Morph; in fact you remind me I need to strip the gauge again.  My pump stays on the frame in all weathers.  Maybe yours does too and suffers in the same way.
What I've found is that the gauge can get muddy water in it, with enough grit to make the moving parts stick, either completely or partially (the latter cost me a tyre when I overinflated it and blew out the sidewall).  It wasn't seals that were the problem, but the spring and sliding indicator.  A good rinse and re-grease did the job for a year or so.
Even if you can't fix it and the gauge is in the head, you may be able to replace the entire head, either with an identical one (probably the best idea for portable pumps as you don't want it flapping around) or a similar one (on a track pump).  On my track pump the gauge isn't on the head but on the pump itself - it does however use a standard pressure-fitting thread so any pressure gauge of the right range would do.


Are there valve caps that show the tire pressure?

These types of valve cap gauges aren’t recommended - either for cars or bikes. They work by bypassing the schrader valve in the tire and using a cheap spring-based pressure gauge in the cap.

First, they’re wildly inaccurate even on cars. By the time they show red, you’re riding on your rims.

Second, they’re cheaply made and a significant second point of failure. If the cap is just a bit loose, the o-ring gets just a bit of dirt in it, or the valve cap gets knocked the wrong way, they will start bleeding air. This is most likely why they aren’t sold in the higher pressures that bikes would need.

Finally, as @Argenti noted, many riders adjust their tire pressure depending on the road or trail conditions or their desired degree of ride comfort. Most bike tires can take a wide range of pressures, unlike cars which have a very narrow band.

Conclusions: I’d just get used to squeezing your tires (for the lower pressure of mountain bike and comfort bikes) and/or topping off regularly (especially if you have a road bike).


can someone identify the year this bike was built?

Possibly a 2010. Note that the "Trail 5" is actually the "Trail SL 5". Your bike looks like the Trail SL F5 on page 60 of the 2010 US Catalog. The 2010 catalog is the first year to include the Trail SL, so it appears your bike would not be earlier than this. Later catalogs don't have the Trail SL 5 in the right color (in Europe or the US). However, there are some differences between your bike and the F5 in the 2010 catalog. Some would be due to component changes (your bike has what look like TRP brakes, for example). More importantly, The F5 had a "5" decal, not "five" as in your photo. I am only speculating, but if 2010 was the first model year, maybe there were some changes to the decals somewhere along the way.


Simple plain English explanation of VO2 MAX

VO2 Max refers to the maximum volume of oxygen that an individual can use at maximum levels of intense aerobic exercise. It is usually reported as as milliliters of oxygen used in one minute per kilogram of body weight, though sometimes you see liters of oxygen per minute with no adjustment for body weight. The former measurement is more useful in exercise and sports science since it allows the measurement to be compared among athletes of widely different weights.

It is usually measured in a fitness lab setting using either an exercise bike or a treadmill. The test subject wears a mask and heart rate monitor. The mask is connected to a device that collects and measures of the volume and oxygen concentration of inhaled and exhaled air.

At some point below maximum effort the body switches from aerobic to anerobic processes to generate energy. Exercise intensity is increased gradually until the subject is at a maximum aerobic effort - beyond which there is not or only negligible increase in oxygen uptake. That is the VO2 Max point.

I don't know how much it can be increased in any individual, and there are both genetic and exercise components. This page lists that:

  The average for a sedentary individual is close to 35 ml/kg/min. Elite endurance athletes often average 70 ml/kg/min. One of the highest recorded VO2 max results (90 ml/kg/min) was that of a cross country skier. Cyclist Lance Armstrong's VO2 max was reported at 85 ml/kg/min.

For even more detail, including the associated math, see Wikipedia: V02 Max.


Everything looks right. Whenever using a crank puller but especially when it's taking a lot of force, it's very important to have the tool installed into the crank arm with some real torque, not just finger tight and never loose. You can grease the threads if there's roughness. Here with the nutted spindle it's a good idea to start with the puller either in two pieces like you have it or at least threaded far out, so you know the tool is getting torqued into the extraction threads and not getting bottomed out against the spindle tip. Once it's in there tightly you can use a lot of torque on the business part of the tool.

Square taper cranks are a press fit and so by nature, penetrating oils and the like usually won't do much to help loosen them. That is to say, putting whatever amount of force through the tool that's needed to do the job is all anyone can really do to remove them. There are other methods when extraction threads fail, but they tend to damage cranks anyway.

If getting enough leverage off the other crank is the problem, you can either rest it so it's torquing against a stationary object or take the pedal off and put a piece of PVC over it for a non-marring cheater bar.


What will be the easiest/cheapest way to get lower gearings on my "new to me" road bike?

You seem to have a good handle on your options.
A wider-range cassette, and a derailleur with a long cage, will probably give you the most bang for your buck. Switching from a 39t small ring to a 34t small ring is comparable to switching out your 25t big sprocket in back for a 29t sprocket. This is a good tool for playing around with gear ratios.
If you do go with option 4, you have more options. I recently built up a new bike with 46/30 in front and 11-30 in back. This gives a high enough top gear for me (46x11 is plenty fast for the kind of riding I do), and a 1:1 ratio at the low end, with tight spacing in between. Shimano, FSA, and some of the more exotic brands offer cranks with 46/30 chainrings.


How can I DIY a smaller Anything Cage/Versacage, or a mini bottle cage

There is an option on the market as well, in the Specialized Burra Burra.

While the cage itself doesn't really 'hold' anything, I have one and find it super useful for strapping in any range of item sizes (water bottles, MSR fuel bottles, growlers, etc.). I didn't love the straps it came with, but a cheap ski strap (e.g., this one ) works perfectly. Anything cylindrical stays seated very well against the aluminum tubing of the cage.


I read that "training is needed" before your voice can replace a horn. Why might this be?

The word "c'mon" is a bad choice for an alert word, because you close your mouth to form the M and the C is a back-of-mouth sound that you can't say loudly.  The N sound is a nasal sound, so the volume there is through your nose.

So the only loud part of this word is "---OOOOOnnn"

If your alert phrase was "Come on!"  then it would be better than "c'mon", but the word of volume is some variation on HEY or HOI or OI

Punchier words with a more defined start - so its an imperative sound
Your windtube is simply pushing air without having to make limiting consonant sounds.
It doesn't really matter how your mouth is, you can make this sound with your tongue anywhere
Doesn't matter how dry your mouth is either - you're essentially just a straight horn pushing air.

More so in the road position than an upright, but that there is your lungs, windtube, and mouth while riding.  Not pictured is your diaphragm muscle, which is the hand squeezing the bulb.

If you ever get a chance to play with a sound meter, try it out and see if you find a better word/noise for pure volume.


Worn chain or chainring can cause this, as can a very dirty or un-lubricated chain, especially is there is a stiff link pin. A bent chainring can also buck the chain off.

Another possibility is the derailleur is not providing enough chain tension. This can happen if one of the tensioning springs has broken or has become weak. Check the 'B' spring (at the attachment bolt) or the 'A' spring (where the cage pivots).

Unfortunately the tendency to drop the chain may just be a 'feature' of an inexpensive bike. You might look into fitting a chain tensioner to keep the chain on. Modern 'one-by' drive-trains with a single chainring use 'double-wide' chainring teeth profiles which are much better at retaining the chain. However, this is not an option on inexpensive bikes where the chainring is integral to the cranks.


If the chain rings are badly worn, its almost certain the cassette (rear cogs) and chain need replacing. do not change the chain rings on their own.

The chain rings on most cranks can be replaced. Some cheaper ones (mostly kids bikes) use rivets, and you need to replace the whole crank set. If possible, the easiest thing to do is replace chain rings with identically sized ones. The BCD (Bolt circle diameter) must match, you can vary the number  of teeth but that changes the gearing and might need to adjust or (worst case) replace the front dérailleur, and may also need to replace the rear derailuer.

If you decide to changing cranks, you will need to match the bottom bracket you have, or get a new bottom bracket. if you need to change BB, you can end up in BB standards hell sooner than you can imagine. Keeping the same BB and Crank set is by far the easiest.

Rear cassette - easiest is replace like for like - same speeds and number of teeth on the big cog. As with the chain rings, if you change the number of teeth you may need to adjust or replace the rear derailleur.

Chain - if you keep all the gears the same number of teeth, you can make the new chain the same length as the old one (presuming old was correct), otherwise you will need to work out the correct length for the new chain.

Tools required:

Chain whip
cassette removal tool.
Hex keys
maybe a chain ring bolt spanner
Crank removal tool for your cranks (usually square
taper, but a dozen others exist)
Maybe a BB spanner if replacing BB.
Chain breaker.


It is a women's Trek bicycle, i can't read it from the image but the model is more than likely one of those teal words on the frame. Google Trek and then those words and look for an image that looks the same.

More than likely basic components but if the price is right and you like it a bike is a bike. If there is rust on the chain or crankset it is not in "excellent ready to ride" condition for someone who does not know how to service it.

Trek is a reputable brand but that appears to be a low level model, not that there is anything wrong with that. There should be a serial number on it, possibly the bottom of the frame by the crank, that may also lead you to find the model and year if you then search that serial number.


Shimano front-derailleur with 28.6 Clamp

You can buy a braze on derailleur of the type you need and get a Braze on to 28.6 adapter. Alternately, you can get a derailleur with a larger size and get a shim. Either will be perfectly functional. Very few Mountain Bikes have 28.6 downtubes anymore so the likelihood of finding a 28.6 seems pretty low.


How to fix the tension in these shifters?

Follow the cable from the shifter down to the front derailleur. At the derailleur the cable housing will end and the inner cable will continue to a screw on the derailleur that clamps the cable, take a moment to look at derailleur and find the lever that the screw is on and push it. That should move the cage of the derailleur (the part that shifts the chain).

If the derailleur is moving freely, check the cable it should be relatively tight and should move when you move the lever. If that's not happening – perhaps all you're doing is changing the amount of slack in the cable, then adjusting the tension should help.

The short explanation is to move the lever all the way up (to slack the cable as much as possible). Then loosen the clamp screw on the derailleur and pull the cable through to take up all the slack, then tighten the screw.

For more detail, check out this post on adjusting your front derailleur from Park Tools.


How to clean rim brake track efficiently?

Fold a paper towel a couple of times and stick it between pad and rim.  Squeeze the brake lever and rotate the tire.
Depending on the contaminant you may want to wet the towel, douse it lightly with a solvent, or (to get solvents off) use alcohol.


Most bike shops have access to parts for adult trikes, no matter who the manufacture was, taking the trike in is always a plus (I know it's a hassle) but call first to make sure your working with a shop willing to help you before you haul it in.
I've sent a message with the serial # to one of my vendors to see if it's one of their models (I'll respond later with an answer), no matter; adult trikes used pretty standard bike parts.
please upload Pics I'd like to see it.
later,

Sun trikes informed me that it's not one of theirs, and by seeing the pics
it's probably not a (professional) custom built.
you should be able to find parts for it, just make sure the frame isn't compromised or it's just not worth fixing, you can buy a new one for 300-500 US.
I hope this helps & if you do decide to get rid of it gift it to a local bicycle collective they maybe able use parts off it.


What should I be concerned about changing out wheelsets on a Ritchey Cross bike?

So long as the hub width and rim diameter (e.g. a 700c rim is replaced with another 700c rim) are the same, and the rim is designed for rim brakes, there is nothing to be worried about. If you were moving to a larger tire, you'd have to consider clearance, but a smaller tire will clear wherever a larger one will. The new wheel set should have appropriate rim width to support the desired tires.

The brake alignment won't be a problem assuming you're sticking to the same rim diameter -- the rim width might change a little bit between the wheels, but this is just a tiny re-adjustment of the brakes as usual (if necessary).

The bike will drop in height a little bit as well if you move to smaller tires -- you wouldn't notice it from 28 -> 25, but if you had 40->20 or something, you'd notice.


How to mount wire bead tyres without damaging them?

The classical trick is to move the beads of the tyre into the well of the rim  down to the center of the valley, so that the apparent tyre diameter become larger than the rim diameter. Then the tyre can be pressed with both hands towards the point where the lever can be finally used to insert the bead into the rim.
However, this is almost impossible with Marathon Plus tyres, which have a very strong wire and a inflexible rubber: when one spot is moved into the well of the bead, others go off, so that the diameter is never increased sufficiently.
To solve this issue, I tied several knots around the tyre with strings, so that the tyre is pressed into the rim.

However, with a classical knot, it would not be possible to press the rubber sufficiently so that the tyre would fit into the well of the rim, because these Marathon tyres have very little flexibility. To I used a Tarbuck knot, which makes it easy to get the sufficient pressure. One knot every 3 or 4 spokes allows to get a constant pressure.

It is then quite easy to push both sides of the tyre towards the point where the remaining work can be done with the levers, but without excess force.


can only use right hand to brake reliably, due to disability - safer/possible to modify bike?

Generally speaking your off hand should be the front brake, so if you're right handed the front brake should be the left. They can be set up either way, though, especially if you're using cable-driven (non-hydraulic) brakes. Even with hydraulics you should have no problem making the right hand brake the rear. I would highly advise this, as in a panic situation while mountain biking if you grab the front brake hard, you're more than likely going over the bars.

There are levers that work both brakes. They are out there!

Here is one that pulls 2 cables at the same time, so you could use it to pull both the back and the front brakes.
http://www.jbi.bike/web/checking_product_description.php?part_number=13748

There is also a company called Surestop whose product I believe works off of one lever and won't engage the front brake until the rear is already engaged, thus making it very difficult to catapult yourself over the bars. They are for V brakes only though, I believe.

The backpedalling braking is indeed a coaster brake: you are correct on that note.


Do cyclists warrant special consideration under traffic laws?

Before posting this list, I need to preface it with my position that riding in a predictable manner, as much like a 'vehicle' as possible is safest to me.  To a large degree I disagree with treating bicycles differently because:

It confuses interaction with
motorists, especially at
intersections where the risk is
highest for cyclists.
Not all motorists or cyclist will know their
rights/responsibilities.  It's hard
enough to educate both side now.
I think the time/speed/safety gains for
the average cyclist would be very
small.

That said there are exceptions in almost every jurisdiction already, allowing use on paths and sidewalks, allowing passing on the right, etc. - these are the common arguments I hear in favor of different treatment, primarily as it relates to an Idaho style 'Stop as Yield' law:

Bicyclists have to expend their own energy to start and stop--it's a courtesy to let them pass just as it is to yield to someone carrying something heavy or bulky.
Bicyclists have better awareness of surroundings (better field of vision, higher than cars. fewer distractions).
Bicyclists can avoid collisions better (sharper turning radius, much less width, less speed and weight to manage, can become flush with the side of the road almost instantly, can stop in a shorter distance);
Most bicyclists treating a stop as a yield pass through stop signs at a similar speed as most motorists (who usually don't stop), but comparing the straightaway speed difference, it may seem like the motorist is "stopping" while the cyclist isn't.
Stopped cyclists are unable to avoid the pollution of stopped cars. Pollution tends to be highest at stops.
Cyclists waiting in traffic can cause more problems for all--not only by blocking turns (which often elicits prejudicial anger from motorists) but there is an increased chance of being rear-ended for the cyclist. (Proper lane positioning avoids this - gr)
Frequent stopping is associated with long-term chronic knee problems from the pressure required to start again.
Most cyclists responsibly "run" stop signs at present, showing that the law simply doesn't work for people.
Cyclists don't endanger the public as cars do and have not been properly accommodated for--this is due in large part to short-sighted planning that doesn't recognize the benefits of cycling.
Places that treat bicyclists as special users, with high levels of accommodation have much lower bicycle fatality rates than the USA (e.g., Netherlands, about 1/13 our fatality rates per mile traveled). One of the reasons is that they give cyclists a head start through red lights, with special zones ahead of motor traffic, and special bicycle-only green lights.


Can I ride through unoccupied carpark spaces?

AFAIK there are no road rules requiring you to give way to traffic behind you when travelling straight down the road, ie, not turning and not at any intersections.

Riding over an empty carpark space is also completely legal and normal.

There are places where one must not ride more than 2 abreast, and some locations have rules about impeding lane flow, but you're not describing that situation.

You've simply met an impatient driver, not much you can do for them.  Have patience and tolerance.


Why does cycling use a measure of time ("century") as a measure of distance?

A distance of 100 miles (161 km) is often referred to as a century. Century is also a common designation for 100 years, but that is not its exclusive meaning. The English word derives directly from Latin centuria, a group of 100 [etymonline]. This is a form of centum (or CENTVM if you will) which simply means (one)hundred.

A ride of 100 miles is thus aptly named a century ride, without having to resort to metaphors or figurative meaning.

Chris H mentioned another instance where century is used to count something other than years: In the sport of cricket, a century is a score of 100 or more runs in a single innings by a batsman [wikipedia].


What type of cleat is this? Should I save it or get new cleats?

It's a Shimano SPD cleat. There are a few different models, but they are all cross compatible. You can reuse the old ones if you can unscrew it, but new pair should be under 20€, too.

EDIT: Looks like this is an old Shimano cleat, like this one: http://www.fixedgeargallery.com/reviews/dzr/ovis/10.jpg. Modern ones and most copies have a sharp angled "shoulder" on the middle section.


With this level of information, the only good answer is to say,"Find a competent bike mechanic, and ask them to look at it."


Why did both of my inner tubes blow out on a new bike I've only put 4 hours on?

I have had a couple of times that an inner tube blew up while the bike was parked in bright sunlight. It seems that high temperatures are a contributing factor, but overpressure? I never pump my tires close to the maximum pressure, mostly the pressure is in the lower half of the min-max range.

The pressure of compressed air increases proportionally to the absolute temperature, i.e. 273+T ;  T in degrees centigrade. Hence an increase from 95F (35°C) to, say, 140F (60°C) will result in an increase by only 8%. I don't believe this itself is causing the blow outs.

More likely the blow outs are due to an undersized inner tube in combination with a high temperature. Rubber is a material that behaves elastically in a limited range. Beyond a point it starts a plastic deformation. I guess that this point drops with higher temperatures. Most inner tubes are specified for a certain width range, e.g. 18<-->23C for road bike clinchers. The remedy is to buy an inner tube that matches closely with the tire width.


This is common and not really controllable by the mechanic after freehub service. As long as it's engaging without issue it's fine. The click will work its way back eventually. Thicker lubricants cause more of this but it depends on the design of the hub as well. If too much lubricant or something too viscous was used, that's its own problem, but quieting the pawls down isn't necessarily an indication of that.


How to prevent trailer hitch bracket rotation?

Based on the image of their hitch that I found and added to your question, you're going to have to modify the hitch to make it work. It's designed to rotate (I don't think that's a good decision, but that's what they did).

If you have enough clearance between the trailer and your rear wheel/mudguard, you could rotate the hitch forward and clamp it to the chainstay. I'd use a jubliee clip (hose clamp), and leave it there permanently. The problem with that is that you won't be able to remove the rear wheel without removing the clamp. If the chainstay sticks out past the dropout it's also going to bend the hitch when you do the axle nut up, which I would not do.

The other option is welding a bump/tab onto the inside of that clamp as described by solson. I strongly suspect that mount is steel, so it's easy enough to weld onto. If you don't have a welder it's going to be 10 minutes work for a metalworker to do it, plus you will need to repaint the hitch afterwards. I would buy a second hitch for this, since Croozer sell them, and that way if you stuff it up you can still use the existing hitch. If you're paying, clean as much paint as you can off the whole hitch (welding will heat the whole thing up and burn off paint over much of the hitch, which is stinky, so if you don't do it you're going to be paying someone else to do it). Then work out exactly where you want the tab and scratch marks along each edge, from the hole in the middle right out and down the outside edge (so they're visible after the weld covers the scratches on the inside surface). The welder will put a blob that extends past the scratches (molten metal doesn't sit in nice box shapes), then you will file it back to get nice straight edges that will lock in place nicely. If the metal place is able, oil quenching after welding will harden the bracket which will be helpful.

What you're trying to get is the red blob added on the dropout side of the hitch, so it sits on the slot in your dropout when the wheel is installed.


Using a new but potentially dirty olive and barb when shortening hydraulic brake hosing

While I'm not sure whether it's going to be an issue if you leave it, it definitely won't be if you clean it just to be safe. Something like disc brake cleaner will clean off any contamination without leaving a residue behind.


Which holes to use for mounting rear rack?

The quick release skewer is the lower mounting point, remove the skewer pass it through the rack and reinstall. After the lever is tightened, verify that the threaded rod end comes to the edge of the acorn nut. If the threaded rod is not visible you will need to source a longer skewer.


I have a schwinn ranger 24" with a tourneyTX derailleur, what options/alternatives do I have to change the rear derailleur?

The easiest thing to do of course is simply take it to a bike shop. You'll get the correct part and the gears set up and adjusted properly.

If you want to obtain a replacement yourself, you can order a replacement Tourney TX from an online bike components store, however, there are several variations of Tourney derailleurs available you need to take account of.

Schwinn does not seem to list any info for the Ranger 24" model but looking at some online retailers that are offering it, it's a 7 speed, uses a direct derailleur mount and seems to have a medium cage length.

Target.com lists a Ranger 24" here: https://www.target.com/p/schwinn-boys-ranger-24-mountain-bike-black-red/-/A-50676983. That bike seems to have a Tourney TX35D model derailleur.

You'll want to check that the bike at Target looks like yours as it may not be the exactly same as what you have.

Niagara Cycle has a good selection of Tourney TX  derailleurs available (and TY, which appears to be a slight upgrade). You should be able to find something that matches the mount style (hanger or direct), number of speeds (I'm fairly sure all Tourneys are 6 or 7 speeds) and cage length that you need. If you are not in the UK, Canada or Australia you should be able to find the correct model on Amazon.com or another online retailer.


I have used old wine cask bags (or bladders, readily available in Australia, not too sure about rest of the world) packed either into a pannier or strapped onto the top of the rear rack (not the best position but I was fully loaded).  Some would say the slight after taste of wine is a bonus.  I have also seen unused bladders available from some camping stores.

I also have carried water purification tablets just to be safe.


Is it possible to do 50 km distance without any previous training?

A fit person can do 50km without too much difficulty, though they'll probably be sore from the effort if they don't cycle much, just because cycling uses different muscles to, say, running.  It wouldn't be easy, but it wouldn't be too hard.

It sounds like you're not very fit. If you were determined, you could probably make it around 50km but I doubt it would be enjoyable at all.  I suggest that you start with shorter distances. Try riding 10km and see how that feels. Once you can ride 20-25km fairly comfortably, doing 50km will be a nice challenge: not easy but an achievable goal that you can look back on with pride.  Note that gravel and especially sand are more work to ride on than the equivalent distance on the road.

Since your bike's not been used for a while, you should get a bike shop to check it over. Depending on how much it was used and how it's been stored, it might need things like a new chain, new cables and new brake blocks. Possibly new tyres if they're in bad shape.

If you're going far from home, make sure you know how to repair a puncture (bring a spare inner tube so you don't have to use patches unless you puncture twice) and that you have a way of getting back if everything goes wrong.  Rather than cycling to somewhere 25km away and then coming back, consider arranging your ride as more of a circle so there's a shorter route home if things don't go well.

Make sure you bring water and snacks with you, since your first 50km will probably take at least three hours.


What is correct procedure to remove freehub body?

It turns out that my freehub part was a type 49N Quick Release for which I have a hard time finding documentation. However, what I can tell is that I had to insert a 12mm hex key from the other side of the wheel. This 12mm HEX key was used to unscrew a bolt located inside the hub with the thread on the outside of the bolt holding the freehub in place.
Amongst the 5-6 tutorials I watched online, not even one mentioned the existence of that system. I found a replacement in a local bike shop so almost ready to go. Thanks.


Buy and fit new ball bearings.  They're under $5NZ $4US for a set.  Its false economy to not replace them when the headset is open.

Headset bearings are probably best in retainers rather than loose bearings.  They don't roll a lot compared to wheel or BB bearings, and there's a lot of small bearings around a relatively large race compared to wheels.


Can I upgrade cassette without replacing rear derailleur?

The derailleurs are usually matched to the size of the cassette/chainrings.

the cage length of the rear derailleur is matched to the largest cog.  that is why you see mountain bikes with a 34 tooth in back with long cage derailleurs and road racing bikes with the little derailleurs matched to the corn cob size cassettes.

The curvature of the front derailleur is often matched to the size of the chain-rings.  This feature improves shifting.

if the differences in tooth count are not too drastic, you might be able to get away with only swapping out cassette and/or chain rings.  Also the number of links in your chain may have to be adjusted.


Proper Posture for Preventing Painful Posteriors on Penny-farthings?

Penny-farthings are known for their relatively harsh ride, and lack of stability. There is no option on many frames to replace the saddle, although there were some that you could. I would get a sprung Brooks saddle, or similar, which might add a bit of comfort without significantly sacrificing the vintage look.

It will add a bit of suspension effect as well.

Something like this:


Underinflation is bad for tyres.  Your pannier won't have caused this, other than adding more weight to an underinflated tyre.

Its likely that riding underinflated, combined with stresses of changing the tube last month, have damaged the tyre.  Possibly a tyre lever used wrong may have contribited too.

You should replace this tyre, and inspect the front tyre for similar damage.

I see a moderately knobbly tyre - if you're riding roads then consider more of a neutral commuter tyre tread for easier riding.


Flashing light when pushing bike with (constant) low speed

This happens because the power from a hub dynamo (which technically is a magneto, not a true dynamo) is not clean sine-wave AC but consists of short pulses with alternating polarity. At high speeds these pulses follow each other fast enough that a LED can burn continuously with a small capacitor and a filament bulb does not have time to cool down between pulses.

The effect does not have anything to do with programming or the fact that LED is a diode, and it happens with filament bulbs too. A more complex LED setup could have a capacitor to enable continuous dim light and perhaps even be programmed to flash at low input power, but I doubt this is the case.


There are various gearing calculators available on the web. Here is one of them: http://sheldonbrown.com/gears/

The top possible speed will depend on your gearing, wheel size, and max cadence. Of course, your ability to reach that theoretical top speed will be limited by your own strength and fitness.


Are heavily worn rims safe to use on trainer?

I don't see why not, unless you plan on braking while on the trainer? Theoretically you could still have a rim failure because the wheel/tire pushes against the resistance wheel. However, this is a constant tension, not sudden impacts. If a spoke were to become loose though, the rim could fail and the wheel could implode, but since your on a trainer it's not really all that dangerous (besides picking bits of wheel out of your drivetrain).


John Allen has an article on some common reasons why chains drop, which I think is worth reading. Wrong chain size, bad derailleur adjustment, insufficient derailleur capacity, chainring damage, etc.  are some reasons this could occur.

There are clutch rear derailleurs (common in mountain biking) which try to keep the chain taut-er when going over rough ground, where a regular derailleur might move in a way to reduce chain tension and lead to dropped chains. But rough handling on any bike increases the likelihood of dropped chains or things switching up on you.

Shimano calls their clutch rear derailleurs "Shadow" and SRAM calls them "Type 2".


Can I combine different wheel sizes in one mtb?

Technically it can be done. Different wheel sizes were used over the years, starting from late 1980s in some niche touring bikes, where front wheel was significantly smaller than the rear one. Mountain bikers have used a setup of 26" wheel at the front and 24" at the back, especially for downhill (even at World Cup level) at the beginning of this century, when frames tended to be suspended ridiculously high. However with the progress in frame design, this idea lost its popularity lately.

The points raised in favour of the 26"/24" setup were:

lower bottom bracket, thus lower centre of mass meaning better control on the downhill
"flatter" head tube angle, which gives better stability at high speed and again, more control on descents
smaller wheel is easier to propell
smaller wheel means shorter spokes, which adds to its stiffness,
shorter effective top tube which helps to lean more backwards on really steep sections.

Arguments of the other side were:

lower bottom bracket could mean hitting the ground with your crank when frame suspension is fully compressed (applicable to full-suspension bikes only, but only such bikes used this trick at the time)
You need relatively higher pressure in your rear tire to make up for smaller volume of it. This in turn will give worse grip of this wheel,
Smaller wheel will generally have a smaller area of contact with the ground, which can mean worse grip, but also posibility of getting stopped by obstacles which could be overcome by your front, bigger wheel
Due to flat head and seat tube angles, going uphill, especialy on steep and technical fragments can get more tricky (obviously no one would ride uphill on their 25kg downhill bike back then, this is more applicable to today's bikes)
worse aerodynamics, but it's not what you do it for.

Most of these points are equally valid for all configurations with the larger wheel at the front. Basically the goal of such change is usually to make a bike beter on the descents, not looking at its performance on flat gruond or uphills.

Now to your specific case: note that the difference between a 29" and a 27.5" wheel is not very significant - ~6% when we look at ISO rim diameters. Therefore if you aren't too sensitive to geometry changes, you may not even feel the difference.

And obviously you need a 29er frame for this to make sense. If you decided to put a 29er fork and front wheel on a 650b frame, you would end up with a bike unsteerable on flat surfaces and exhausting to your knees. There are a few bikes on the market which use various wheel sizes, such as this Trek with a 29"/26" setup, but it's still a niche.

On the side note: a small brand called Unibike once made a cross-country bike with a 26" wheel at the front and 29" at the back. This idea seemed a bit pointless for off-road use, but they tried to forces itfor some 2 years, before letting it die.


Mechanical disc rotor for CUBE MTB - front wheel : Shimano 559x17-21c

As you wrote, your bike already uses 160 mm Centerlock disc at front. If you need a new disc instead of worn/damaged old one, any 160 mm Centerlock disc will be compatible.

There are some concerns about certain brake pads types not being compatible with all disc types, but in my opinion it does not matter, all pads just work with metal discs.

Do not go with different diameter of discs unless you experience lack of stopping power. If so, bigger 180 mm discs may be an answer, but you'll need to check if they are compatible with your fork and won't break bicycle warranty. Besides, an extra/different adapter is usually needed to install a disc of a different size.


This stuff is not expensive.  Simply unpick the stitching, and replace it.

The hardest thing will be doing the stitching in a way that will stretch, because a plain straight stitch will not work.  A fancy modern sewing machine can do these stitches, as can an overlocker.

Example pricing seems to range from a few dolleurosuid to tens of them.  It gets cheaper in larger lengths, with 50 metres being under $1 / metre.

https://www.aliexpress.com/w/wholesale-silicone-gripper-elastic.html  for example.  Keywords here are "silicon grip elastic"


Does stripe in Selle Italia saddles form a channel?

To answer your question, no. The leather/lorica/covering has no bearing on the shape of the saddle. They make a lot of versions of each design specifically for bike manufacturers with custom designed coverings in addition to their standard covering design.

They make quite a few saddles with grooves, without grooves, with and without cutouts. It's not entirely clear which model this is from your image or description as they do not have an "SL" model on their current product listing. They do have an "SLR" line and the shape appears to be of the "SLR monolink" variety which has both a non groove and groove model within it.

As stated above in the comments, it's best to go to your local shop and ask that if they do not have the item in stock, that they order one for you. Most will oblige because they can send items back if they are in unused condition. Some will ask for a deposit as a "holding" fee to ensure that you don't ask them to order a bunch of stuff and never come back.


Even though I don't have specific knowledge on road bike tires, nor specific numeric durometer designations, I have some expertise on MTB tires. The given specification numbers mean that the bike has a slightly harder rubber compound on the rear tire.

The reason for having different tires front and rear is that the dynamic loads that each tire has to cope with are different, all depending on bike geometry, rider technique and skill level and type / usage of the bike.

The rear tire copes mainly with traction load, that is pushing the bike forward, also side load from turning but less than the front tire and a little fraction of the braking forces. Also during acceleration and rolling on flat, it bears a bigger fraction of the rider + bike weight.

Front tire on the other hand bears with almost all the braking force, specially on road bikes. It also copes with most of the force needed to steer the bike, which means greater side loads than the rear tire. Also, in strong braking the front tire bears with a bigger fraction of the weight.

When a forward moving wheeled vehicle brakes, a weight transfer occurs from the static center of mass towards the front of the vehicle. This is easily observed on cars, motorcycles and full suspension bicycles. That's why front tire works harder during braking, because the rear wheel has lesser downward force applied to it, so it is very limited on the friction it can create.

In the particular case shown on the question, the bike has a slightly harder rubber compound on the rear tire. This means that it will last a little longer and will create a little less rolling resistance (Compared to a tire with the same structure but using the softer compound and keeping all other variables equal). Conversely, the front tire, being softer will have more grip and will do a better job braking and steering.

In my opinion that makes sense because on a road bike, you spend more effort pedaling on flat or climbing, and during such events, the rear wheel has a grater fraction of the weight applied to, that is, the bike has less rolling resistance than if it had both tires made of the softer compound, but a little more grip than with both tires made of the harder compound. It's like trying to get the best of both worlds.

In MTB where my experience comes from, different threads is common practice. It is usual to pick tires independently, even different brands. Some manufacturers even have front and rear specific tires with the same model name. Others design a rolling direction for front use and the other for rear use.

On my particular case I have bikes with different tires front and rear but also bikes with the same tire model. While comparing wear on different tires is very difficult, on the bikes I have with the same tire front and rear, there are different wear patterns.

On and old road bike that I have with cheap identical tires front and rear, I use a little more pressure on the rear tire, for the reasons explained 3 paragraphs before.


Adjustment to road bike brakes for high grade downhill

Have a look at installing Cantilever brakes- larger pads so you can retain the same stopping power and increase life, at the expense of a few grams of weight.  Cantilever brakes will also help in the wet due large pad (more surface area). These are the preferred brakes for tandems and tourers - you may have trouble getting decent quality ones these days. As I understand, V brakes are not compatible with road bikes without adapters and are not always as successful as you would think.

Discs would be the ultimate wet weather improvement and provide the stopping power you want, but I would caution against hydraulics for such big downhills. They have been known overheat and boil the fluid - you get instant total failure when it happens. Apart form this, you need new forks and wheel (minimum of a hub), and probably new levers, so the cost may be prohibitive.


What are the differences between Specialized Targa and Henge?

So, today I got both saddles, and I can answer my own question :-)

Those saddles are twins, you know already about the weight difference (Targa is heavier), and the only difference I found which was not in spec is flex of the shell. Henge is very stiff (the shell, not the padding), while Targa is rather flexible.

And while I am writing this, I rode Henge Test 143, it is very comfy for male organs (three of them), however because its wings don't flex down, it constantly gets in the way of moving thighs. 130 version might be the better though in this regard.


With bike hubs you are generally safe buying a high-quality generic replacement as long as it's actually the same bearing type, same dimensions, same kind of shields, and with 100%-ish grease fill. Getting all those things can have some subtleties.
If you're getting something from outside the bike world, like a local bearing house, you want to ask for 100% grease fill or add it yourself, because otherwise you won't get it. That said I'm not sure that the 18307s for the front exist outside the bike world.
Within the options packaged and sold for bikes you'll probably find there's at least one applicable option each from Enduro, Phil, and others. You may also find you have a choice on the seal type. Your front ones, again being kind of weird and made-up, may not pronounce the seal type or anything else on the existing bearings. In that case you'll need to either choose how aggressive of sealing you think you want, or examine the old seals and figure out what they are (LLU, LLB, etc) if you want it to match exactly. That said if you're wearing out bearings on a mountain hub it often makes sense to just get the most aggressive sealing you can find.
Perhaps more to your real question, yes it's mostly fine, since in many cases the good quality aftermarket options are as good or better, and sometimes a lot better, and in practice there is often confluence between needing to replace the bearings in the first place and the original ones being junk.


I got a 27.5" fork for my 26" bike, what size wheel should I run?

You probably have a different offset and a different fork height now, so whatever you do, you have already messed with the geo noticeably.

Borrow a 27.5 and a 26 front wheel from a friend for a day, go ride, figure out which one feels better. I would guess 26 would feel closer to how it used to but it should still handle differently due to the different offset, but who knows you might prefer the 27.5 even though that should leave your geo even more altered :)


Your local bike shop should be able to sell you some carbon gripping compound, for example Finish Line Fiber Grip.  Other similar brands are available!

I've no idea what the seatpost clamp is on your bike but I'm always suspicious of ones that are hand tightened.  I have 2 bikes with carbon seatposts & Ali frames, I use Salsa clamps that require an allen key & I don't experience any slippage.


Can someone give me a short description and comparison of the different road cycling pedal / shoe systems?

First up, I'd strongly recommend switching to clipless pedals. I had the same discomfort issues you're describing with normal shoes and toeclips and find clipless pedal so much more comfortable and secure (therefore safer).

When comparing and evaluating clipless pedal systems, some of the more important attributes are:

Float - This is the property where the foot can swivel on the pedal while clipped in. Some pedals allow the float to be adjusted independently of the tightness, while other pedals have only a single adjustment for both. Also, see this answer.
Ease of entry - Some pedals require the pedal and cleat to be lined up carefully before the cleat can clip in. Others are orientation agnostic and a good stomp is usually enough to engage the cleat.
Compatibility with shoes - Most shoes have either the 2 bolt SPD pattern (typically mountain bike and more casual style shoes) or the 3 bolt SPD-SL pattern (typically lighter and more stripped down road shoes)
Availability - How easy it is to buy parts, cleats and pedals.
Surface area - The size of the contact point on the shoe. This can make a difference in how evenly the pressure of the pedal is distributed to the foot.
Walkability - How easy it is to walk while wearing the shoe with the cleat.

These attributes for a number of different brands are compared in the table below.

Shimano SPD

The most common style of commuter and mountain bike pedals.

Shimano SPD-SL

The most common form of road bike pedals

Look Keo

The first popular road bike clipless pedal.

Speedplay

The speedplay pedal is becoming more popular with many professional riders now using it. One advantage is that there are no moving or wearable parts on the pedal, providing exceptional durability.

Time Atac

The Time Atac is another mountain bike style pedal

Time equipe

Time equipe is the road shoe style Time pedals

Crank Bros Eggbeaters

Crank Bros Eggbeaters are commonly used on mountain bikes where their simple design is good at shedding mud. There is some question about the durability of the bearings, however replacement kits are available, making these pedals more repairable.


For road riding, are mountain bikes safer than road bikes?

I would say it's debatable and depends on the individual's preference. Mountain bikes (MTBs) obviously have more traction due to wider and more grippy tyre designs. However a road bike could hold a turn better due to lack of shoulder on the tyre. Speeds tend to be lower on a mountain bike due to added weight and those grippy tyres. On the other hand these slower speeds could be a disadvantage in road traffic. (for reference I ride both an MTB mainly off road and a hybrid with road tyres for paved trails and roads)

I would recommend looking at better/further safety equipment (knee pads, elbow pads, gloves etc) and/or training rather than a new bike. For one, It's cheaper, but it will also install confidence.

Another option is to try with a rented mountain bike to see which your son prefers.


Failure modes for suspension forks, air and coil

Basically the air and oil seals get worn and leaky. You'll get less air spring pressure, droop and increasingly poor damping.

Of your options, 2 and 3 are not realistic. If the air spring pressure drops to zero (relative to ambient atmospheric pressure), there is no force to extend the fork. With no air spring pressure the stanchions will not slide freely on the legs because the oil based damping system is still working.


It's a good observation.
Symmetrical flange spacing and the maximized total spoke tension it provides is exactly what one wants in some applications, but not all. If you're designing a hub you have to think about what is enough total tension and then parlay the benefits of getting "extra" strength above that amount versus the drawbacks of reducing the bracing angle, albeit only in one direction. When wheels fail in practice, a pretty meaningful percent of them fail from side loads. So when you see this asymmetry on hubs that could have been made symmetrical, it's the designer making decisions on what will actually produce better reliability on average.
An exaggerated version of the same thing is seen on track hubs. They're the most could-be-symmetrical hubs of all, but proper track racing hubs usually aren't. The reason is that radial overloading is just not that much of a concern, but crashes and heavy sprinting riders rocking the bike side to side are.


Hydraulic disk brake stops working when hot; back to normal after cooling - is this expected?

The least you need to do is bleed the brakes to remove trapped air. It's best though if you completelly change the fluids and bleed. You can do that in an LBS, or yourself if you have a bleeding kit and know how to do it.

The reason for the behavior you described is that air is trapped in the system and makes things mushy and unpredictable. The fact that after a couple of lever presses it came back to "normal" is because hydraulic brakes are auto adjusting both on the pads end (when pads are worn) and on the lever end (when air is in the system).

Air bubbles exist in the system either because a proper bleed was not done in the first place or because the fluids absorbed moisture which vapourated and turned into air as soon as you overheated the fluids. Also note that as soon as the fluids absorb moisture (water) then the boiling point falls even more so having this issue is even easier.


What is the name of the part between a wheel hub bearing and the fork, and where can I find a replacement?

I think you are referring to an end cap. On some hubs, you can actually change out the end caps to accommodate either quick releases or thru axles (and for those, you can get end caps for 15mm or 12mm axles). Many older hubs don't have end caps, but many current generation disc hubs do, because road bikes sometimes don't use 12mm front and rear axles. Hence, the end caps may be detachable, and yours appears to have detached.
In an earlier version of this answer, I had missed the fact that Sun Ringle now supplies complete wheels. You should be able to approach either an Orbea dealer or Sun Ringle itself for spare end caps. Hopefully, Orbea just misinterpreted the term “hub spacer” when you asked the first time. When you say that, I would tend to think of the spacer supplied with some Shimano cassettes for use with certain free hubs.
The hub appears to have Orbea's own logo on it, so I the company should stock the appropriate spares - and their dealers should be able to order them from Orbea. Hence, if you're near an Orbea dealer, you could ask them.
However, the name for the wheelset that you gave does correspond to a Sun Ringle wheelset. I previously thought that company only made rims, but they also have a wheelset by the name you indicated, and they have spares for their hubs. Hence, you could also contact Sun. However, the link I provided does have a different looking hub, so you would need to tell them that you're after a previous hub model. In my experience, companies in general will usually have spares for older versions of their product, although this isn't guaranteed. If you approach an Orbea dealer, they might not be as familiar with all the smaller spares that the company stocks, and it might be a bit more difficult for them to locate spares for older models. Remember that there might be a large number of stock keeping units (SKUs) involved. If you approached Sun Ringle themselves (or more likely Hayes Corporation, their corporate parent), they should be able to help also.
Last, if you're in the US, Hayes appears to list Quality Bicycle Products (QBP) as a dealer; QBP supplies just about every bike shop in the US, so any shop might be able to search their inventory if you and they can identify the hub in question.
A tangent: why is all this so complicated?
This complexity stems from a classic make or buy dilemma. Many wheelset manufacturers or bike companies that have a captive wheel brand have OEM hubs. In context, they might buy the hubs from an OEM company and brand the hubs and/or wheelset to themselves. After all, making hubs is not exactly a simple business. If you are, say, Cannondale Bicycles, you specialize in designing bikes, not designing hubs. Hubs are quite complicated, so most entities in the bike industry buy them from specialty manufacturers. These arrangements are pretty common, they are not underhanded. Frame design usually operates similarly (which is why I said that Cannondale specialized in "designing" bikes, not necessarily in making the bikes in their own factories; I know that Trek made its top end bikes in the US at some point, but I think they no longer do so). For rims, I know for sure that Enve's factory is in the US, but most other prominent rim suppliers probably supply the designs to a Taiwanese or mainland Chinese factory. Back to hubs, Bitex and Novatec are two Taiwanese companies that supply a lot of OEM hubs, FYI. In contrast, DT Swiss does make (or at least design, but I don't have specific information here) both rims and hubs.
Alternatively, more sophisticated wheel companies might supply a design or design parameters to a factory, which would make the hubs for them; in that arrangement, the intellectual property for the hubs would rest with the designer (but NB: hub spare parts like freehub bodies and endcaps might be common to the hub manufacturer). My understanding is that at least some higher-end captive wheel brands use this arrangement. There are many boutique hub manufacturers as well, and very few of those firms make their own rims - and when I say “make”, I do include cases where they design their rims but contract with a factory (usually in Taiwan, sometimes mainland China) to make the actual rim. Last, in some cases, it can be confusing as a company might use multiple OEMs for their wheel lineup. I think that at least some of Bontrager’s entry level carbon wheels use Formula as the OEM hub maker, but I think their higher tier wheels may be the company’s own design, possibly contracting with DT Swiss for the hub internals.
Back to the question, in the (unusual) case where you knew the actual OEM manufacturer for the hubs, you could see about trying to get spares for those hubs. You usually wouldn’t call up Bitex or some other company in Taiwan, but individual wheelbuilders often use those hubs and would know where to get spares. If you were dealing with an identifiable wheel manufacturer, like Roval or Cadex, you could approach a dealer for the brand - however, note that those two firms are captive brands to Specialized and Giant respectively, so you'd really be talking about dealers for those bike companies. They are under the same corporate umbrella, and many Specialized or Giant bikes come specced with the captive brand's wheels. Captive brands may be managed independently from the parent brand; I recall that Cadex definitely doesn't share its management with Giant. However, I can't readily identify the OEM for those hubs. I know that at least some of Hunt Wheels' wheelsets used Novatec as the OEM supplier, but not all of them do - I think I heard that Hunt was contracting for proprietary hub designs, but I don't know their manufacturing partner.
In your case, I don't think that Orbea has its own captive brand, even though the company's own logo is on the hub. I suspect they may have contracted with Sun to supply the wheelsets and paid them to have the hubs branded to Orbea.
Also note the comments on this answer and the main question: it may be possible to have an endcap machined or 3D printed for you, although I don't know how much this would cost. Since this is your front hub, the endcaps should be symmetrical, and you could use or supply the opposing endcap as an example.


Shimano 105 Rear Derailleur Housing Frayed

It's there to reduce friction when the derailleur is in its extreme positions and also to prevent contamination of the housing. It's not totally necessary, but if it's broken in a way where it can't do that anymore, replacing it will improve performance.
It's unfortunate that the first generation Shimano road 11 rear derailleurs were built to need them to perform well, but they do.
Shimano sells them. I believe their part number Y5XX38000 is a generic replacement for all the derailleurs that have it.
You can also remove it completely when the housing is out and replace it with any sufficiently long nosed shift ferrule to accomplish the same thing. It doesn't have to poke out as much as the original, only enough to route the cable around the bend that gets created in the extreme positions.


Pinion gearbox + Gates belt drive - what are my options for 36-hole rear hubs?

Hope Pro 4 Trial/Singlespeed Hub is available in 36 hole configuration.

Here is a link to the product page:
https://www.hopetech.com/product/pro-4-trialssingle-speed-rear-hub/

You should be able to source them through your local bike dealer or via the internet. The are available for quick release and 12mm axles so you should be able to fit them to your new frame.


Discs have a much higher clamping force. For rim brakes, there's usually quite a bit of movement; you can run the brakes with 5mm clearance from the rim and it'll still work fine. With discs, the pads move a much smaller distance, allowing them to use higher leverage ratios. For example, people running hydraulic rim brakes found themselves crushing rims from all the power.
I imagine this allows disc brakes to have more authority while braking. Water isn't capable of forcing itself under the pads due to the high pressure. Discs also heat up more and can run more aggressive pad compositions (because rapidly wearing out an aluminum rim isn't an issue anymore).The best MTB brakes use sintered metallic pads, which still offer crazy power in the wet.


9-speed Sora w/discs to 11-speed 105 - What Sora bits can I keep?

You'll need:

A Shimano 10 speed mountain/ 11 speed road rear derailleur
A Shimano 11 speed road front derailleur (since they apparently work differently than normal ones)
Shimano 105 shifters (Front and rear; given the cost of a new FD and the resale plan, you don't really want to reuse the old one + the old front shifter)
11 speed chain
A freehub on your rear wheel which can take a 11 speed cassette
A 11 speed cassette

The brakes will work fine. If you do replace the crankset, you'll likely need to replace the bottom bracket as well. The crankset should work, but it might not be optimal -- on SRAM, the chainrings have been spaced slightly wider apart on 11 speed and the chainrings are likely a bit thinner than 9 speed, which may be the case with Shimano as well.


First, it seems as your goal is for a higher ratio on the top end of your gearing so that you won't as easily "spin out"--require such a high RPM to maintain or gain bicycle velocity that it's physically impossible to maintain or achieve such a high RPM.  The fact that you are using a 30 tooth chainring infers that you are on a mountain bike.  That it has a QR 10x135mm rear hub infers it is an older mountain bike or some form of hybrid bike.  In either case--and for many other compatibility and cost reasons--moving to a 12 speed cassette that may have a 9 tooth high gear sprocket to achieve that higher ratio will not work because a 135mm spaced hub has no room for over 11 cogs.  As you realize, you require a MicroSpline free hub for 12 speed Shimano cogs and your current hub is not likely to be compatible for one. There's no point in researching that due to the incompatible spacing to begin with.  Note, as well, that going to an 11 or 12 speed rear will require a new shifter and rear derailleur since a 10 speed shifter has only enough detents (9) for 10 cogs and a 10 speed derailleur is not directly compatible with 11 and certainly 12 speed systems. There is quite a bit of expense there, even if you had a compatible hub and frame spacing, when a bigger chainring will achieve the goal as well.
The easiest--really the only-- way to get a larger, faster top end gearing ratio is to simply replace your current 30 tooth chainring with a 34 or 36 ring.  Thirty-two tooth ring won't achieve much gain in your high ratio.  Probably wouldn't even be noticable.


Riding into a headwind faster than my top speed - how is it possible?

You can do it, because your bike is connected to the ground.

The work done when moving an object is proportional to distance and resistance force (which consists of air resistance and rolling resistance for bikes). The air resistance depends on air speed (ground speed + wind speed), but distance depends only on ground speed. Going slower reduces the energy spent, even when air speed remains high.

As an extreme example, consider just standing in place in wind. You are not doing any work at all, but your air speed is still high. When going against wind, you will soon find yourself doing more work. And when going downwind, you are doing negative work!

For objects not connected to ground things get different. A balloon in 40 MPH wind would drifting 40 Mph downwind in ground coordinates and would have to use the same power to stay in place in ground coordinates as it would use to move 40 Mph in still air.

A numerical example may help. We know the power equation for bicycles. For a bicycle on flat ground, at steady speed so that there is no acceleration or deceleration, in calm wind conditions, for typical rolling and aerodynamic coefficients of drag for a flat bar bike (Crr ~ .005 and CdA ~ 0.4 m^2), and a total mass of 85 kg, the power required to go 30 mph (13.33 m/s) is:

.005 * 85 * 9.8 * 15.56 + 0.5 * 1.2 * 0.4 * 13.33 ^3 = 625 watts.

However, what would the required power be to travel at 5 mph (2.22 m/s) into a 30 mph headwind? In that case, airspeed will be 13.33+2.22 = 15.56 m/s but ground speed will be only 2.22 m/s.

.005 * 85 * 9.8 * 2.22 + 0.5 * 1.2 * 0.4 * (15.56^2) * 2.22 = 140 watts.


Can I install a rack if I install plugin mudguards?

I doubt that will work. If you are going to install the mudguard between rack and tire the “arm” of the SKS X-Blade mudguard is likely to collide with the two stays of the rack. There is a chance that you are lucky and the spacing is just right to fit it through.

If you are going to install mudguards, why not get some proper ones like the SKS Bluemels?

As a sidenote: Why get such a heavy and ugly rack for such a nice and relatively light bike? Something like the Tubus Fly (Vega if you need more tire clearance) would fit much more nicely.


What could be the reason for stem this far away

If the bars were rotated back, they would not be so far away. And, if you wanted to tuck down and get more aerodynamic you could reach the part of the bar that is further away.


Can't remove SHIMANO Nexus FC-C6000 Crankset

You need a crank puller.  It threads in to the crank arm, and presses on the bottom bracket spindle to pull the arms off.

http://www.parktool.com/product/crank-puller-for-square-taper-cranks-ccp-22

A video here from Park Tool on using their crank puller:


Dynamo bike lights - unknown short circuit cause

There are four things you need to know:

Almost all (99%) of bicycle "dynamos" are in fact AC alternators and they produce alternating current (3~6 VAC) with a current limiter (usually 1A max). The frequency of the AC varies by speed.
Most dynamos tie one of the output legs to frame ground (neutral). The dynamo manual will tell you which, but if you don't have the manual you have to figure this out. Some will only have one output and this is the 'hot' side with the frame serving as 'neutral'.
Most dynamo lights take both AC or DC input. The LEDs internally rectify it to DC.
Most dynamo lights have one of the input legs tied to frame ground (neutral). The manual will specify which, but you can also test it out yourself.

If any part of your bike's electrical circuit is accidentally shorted to ground, then the no lights will light. If the headlight draws more amps then the dynamo can produce, then the dynamo's current limiting / self protection circuit may shut it down.

In order to diagnose the problem you're having, you will need a multimeter with AC voltage detection as well as a continuity tester function.

a. Dynamo: First you should figure out which output of your dynamo is tied to ground/neutral and which is hot. If there's only one output, then it's 'hot' and the frame is ground. Use your AC tester to make sure the dynamo is producing around 5 VAC when the wheel is spinning.

b. Light: Use the continuity tester function of your multimeter to see which of the outputs is tied to frame ground/neutral. One of the two will be grounded. If there's only one input, then it's by definition 'hot' but check to see if it's actually shorted to ground. If it is, there's a faulty in your light.

c. Light Try powering the light with it removed from the frame and using a 5VDC  power source. A cheap USB power pack can be used for this or 4 AA batteries. Both are rather current limited so it's a good test to see if the light is drawing too much current (but you could also use your multimeter's current function for this). Your light shouldn't drain more than 2A in most circumstances.

tl;dr: My first guess is that your light ties one of the inputs to ground and you've accidentally setup a short circuit when you wired it in. My second guess is that your front light draws more amps then your dynamo can produce and it's shutting itself down to protect itself.


Sorry, those rims are trash (or wall art).
I'd chase down the seller and demand your money back, and report them on whatever sites they were advertising on for selling items in a known dangerous state.
The crank may be small now but it will propagate in both directions and get bigger. Cracks on thin section aluminum cannot be welded as the heat will destroy the heat treatment state of the metal around the repair.


How long will Ultegra 6800 parts be available?

Don't expect something official. If you don't see it listed on the main page of Shimano's website, production has likely ramped down or stopped.

Resellers will go as long as theres demand and stock. This also controls availability, and its tricky to estimate length of time, especially on less commodity groups (e.g. Ultegra vs Sora; you'll have a lot more Sora spare stock around, just cause a lot more people have Sora). Some retailers show stock levels on their websites, which could give you a rough idea.

This will also depend on your regionality and other things too, so don't expect something reliable.

That being said, you shouldn't worry if you want to just keep things working at a comparable level -- innovations from higher group sets do trickle down to lower ones. So, next year's 105 chainrings may be essentially identical to your Ultegra rings, for example. You could also mix with the new Ultegra (or other sets) where possible. It isn't the end of the world to not have a full set of one kind -- you'll be able to find parts in other group sets or manufacturers which are compatible (especially for things like chainrings). And if you really want a full set of one kind, well, you might end up ponying up for the new one in the future if its that important to you!

Of course, there are exceptions to the prior statement, when Shimano introduces a big incompatibility (e.g. mixing pre-97 ish dura ace with anything requires some trickery, and the Dura ace 7800 had extra tall splines making some compatibility issues for people; price of being on the edge, I suppose0.


My calf catches my derailleur when I pedal

If you're bike is properly assembled, and fitted, then your problems rest not in the bike, but likely in your foot position and your pedal stroke.

First, I would have your bike fit assessed to determine if you're riding the right sized bike, and that the saddle is properly adjusted. If the bike is properly fitted, then you need to change the position of your foot on your pedal and how you execute your powerstroke.

One simple solution may be to switch to clipless pedals if you're not already using them. This will somewhat force you to place your feet on the pedals properly. Other than that what you need is physical training to train your legs to execute a proper stroke. Unless you simply have very large calves, it's likely that you have an improper balance of strength in the vastus muscles of your quad. You need to consciously train your leg not to come within proximity of your derailleur until your weaker muscles get stronger and you develop some muscle memory.

If the reality is that you simply have large calves, then your only solution may be to remove the front derailleur and upgrade your bike to a 1x11 speed. until then, you can try wearing compression sleeves or socks to protect your skin.