Upgrading front suspension for an entry level MTB

Buying bike then immediately trying to upgrade components is a mistake. It would have been better to take all the money available for post purchase upgrades and putting it into just buying a higher specification bike in the first place. Components cost significantly less when purchased as part of a whole bike.

is it as simple as replacing the front suspension with another one that has longer travel

No, it isn't. A longer travel fork needs to be longer to accommodate more wheel movement, the frame needs to have a higher headtube to accommodate the longer fork without altering the headtube angle. Additionally there are compatibility issues with headset bearing sizes. Inexpensive frames use headset bearings that are the same size, better forks use a larger lower bearing.
Ride the bike, save up money, buy a better bike when your improving skills and finances allow.


Bosch uses CAN bus for communication between motor, battery, display.

There is no easy way to read data from it.

check out COBI.Bike it may offer some of features you want.

Else you can hack into CAN bus and read data yourself, the protocol was decoded on some german pedalec forums. (but as I remember there is no torque data in it)


How can I know if a crankset is compatible with my bike without physically seeing it?

In general, you may be able to check the bike manufacturer’s page for your bicycle. They will usually list all the components the bike is built with. However, the list may not be comprehensive, especially if the manufacturer mainly sells lower end brands.
Bottom bracket standards can be confusing, because there are a number of variations. In this case, you could have looked at Shimano’s web pages for the Tourney and Sora groupsets.
The Tourney crank takes a square taper bottom bracket, where there’s a square spindle in the BB. The Sora crank takes a Hollowtech II bottom bracket; here, the spindle is integrated with the crank, not the BB, and the latter is a set of cups with bearings. So, this is a different type of BB.
The term size is ambiguous here. However, your frame most likely has a bottom bracket shell that is designed for threaded BBs, most likely with English threads. In general, in shopping for BBs, you need to consider the frame’s BB shell type, and the crank spindle type.
Do be aware that it is usually not economical to upgrade a lower-end bike piecemeal. Bike manufacturers buy components in bulk from the group set manufacturers, and they get big discounts. It is often more economical to just sell a lower-end bike and get a higher-end one. If the issue is that the chainrings are worn out, then just in case you aren’t aware, you should be able to get single replacement rings. Also, I’m not sure the Sora crankset will be a major upgrade from Tourney. That said, if you are aware of this and you still want to upgrade the crankset alone, you shouldn’t let an Internet forum stop you.


Mountain front derailleur for braze-on mount?

Have you considered cable pull adapter that would allow you use both MTB shifter and present road front derailleur?

Jtek Shiftmate 7 seems to do what you need.

I have not used any such adapters myself yet but I thought you should need about such possibility.


Is the front center pull brake supposed to be free floating?

There are two types of caliper brakes, the side-pull and the center-pull. You have the center-pull but are used to side-pulls.

Side-Pull

You're used to the side-pull. There, the cable comes to one side and squeezes the arms together. Because it's not symmetrical, it uses the pressure of the brake shoes when full-squeezed to center itself around the single mounting pivot. By design, the entire brake can pivot around that mounting bolt:

[

Center-Pull

Your photo shows a center-pull caliper brake. It uses a straddle cable that goes to a yoke (both of these are missing in your example but can be seen below). The straddle/yoke design tends to self-center -- at least if the straddle cable isn't too deformed with age. The brake arms themselves don't pivot around the mounting bolt, but instead pivot on the pivots on the left and right side of the mounting assembly (they had red washers in the photo below). Because of the dual-pivots there is no need for the mounting bolt itself to pivot as part of the brake's normal operation. You can loosen the mounting bolt to recenter by eye and then tighten it back up, but it doesn't float around the center the same way as a side-pull:

[

Both images from wikimedia commons.

A footnote...

Furthermore, I should note that these brake designs from the 1970s were built with much larger brake pad clearances than contemporary brakes. Your shoes might float a good 3-7mm above the rim on either side. Compare that to contemporary brakes which have very close rim clearances, just 1-2 mm. This means that you don't have to be as precise centering with these older brakes -- and you should allow more pad clearance than you might be used to if you have a contemporary bicycle as well. And you'll never get these old brakes to brake as well as a contemporary brake, they will always be weaker and more rubbery in feel.


You need a 20" wheel, tire, and rim strip. You'll probably have some options for what width of tire to get. They start at around 1.95" wide. Most actual BMX frames can take at least a 2.1" in back. There's a degree of preference there. The rim won't care for the most part.

You need to select a rear cog size that both matches the chain length if you're planning on re-using it and/or is a functional combination with your chainwheel size. All the BMX parts sites like Dan's and Albes have extensive guides on this, and there's a question or two about it on here as well.

If you wind up needing a freewheel or cassette cog then you'll likely be buying it separate from the wheel. If you need a one-piece driver (8, 9 or 10 teeth) than typically one selects a wheel that comes with the size you want pre-installed.


Eye protection for child in bicycle child carrier

What is the eye protection protecting against?

Stones up off your back wheel - then install a full mudguard/fender.
UV light?  Then kid sunglasses should do the trick
Bees bugs and insects?  Again sunglasses
Nasty sights on the roadway?  Really dark sunglassess.
Aero advantage?   a fully aero helmet and skinsuit will be required.
Or try nothing and see how it goes - kids don't need to be cotton-wooled all the time, just gotta pick the times.

Note, that second-last one is humour.


Does rim size make a difference to chain length?

The rim diameter of the wheels has nothing to do with the required length of the chain on a derailleur equipped bike.

That does make a difference is the size of the chainrings and cassette sprockets. If you are using the same cassette on both the 660b and 700c wheels then the chain length will not need to be changed.

You dont say when in this process you are switching from 1x7 to 1x10. You will of course need a new 10 speed specific chain when you upgrade to 1x10.


Can an aluminium frame rust from the inside if water has been in it for some time?

Technically rust is limited to iron.   What is bad is the rust starts and continues.  The water / oxidizing agent is not consumed.

Aluminum will oxidize but it forms a protective coating.  An aluminum frame will not "oxidize out".

Some iron alloys such as stainless steel prevent rust.  I don't know why you don't seem to see stainless in bicycles.


What type of hubs attach on only one side?

I think wheel chair hubs are what you are looking for. If you need disk brakes, Cannondale Lefty hubs are another off the shelf solution.


Should I use a Trek Domane SL5 for touring?

People tour on all kinds of bikes. That said, if you're going to tour on the Domane, you'll need to figure out how you'll be carrying your gear, since (as Argenti mentions in his comment), it doesn't have any mounting points for racks.
There are workarounds for mounting a rack (which come with compromises), and increasingly people are bikepacking—using frame bags, seat bags, and handlebar rolls that mount directly on the bike instead of traditional racks and panniers (which come with a different set of compromises). 10 kg of gear is probably close to the limit of what you could fit in a bikepacking setup.


They hold rim brake pads against the rim. When and whether this is useful has to do with both individual style and the brakes at hand, which is also to say the predominant ones in whatever locale or historical era you're in.
Some mechanics view this tool or ones like it as one of the core fundamental bike service tools. Usually that person's default style of setting up a rim brake will go something like this:

Set up the pad position before the cables are run or anchored.
Clamp the pads against the rim with a third hand.
Set the barrel adjusters a distance away commesurate with the target amount of lever travel when finished, minus some accomodation for the cable "stretching."
Run the cable and anchor it pulling it tight with pliers to take out slack.
Release the third hand tool.
Dial the barrel adjuster in all the way.

You can also use a spacer like a credit card or a coin to do the barrel adjuster part. It's two ways of doing the same thing. My bias is the barrel adjuster because it gives more granular control.
It's a fine way, and note that the third hand tool has sophisticated, expensive versions (VAR), simple commercial ones as pictured, and then all the way down to improvised ones made of scrap. That is a big part of its popularity in many times and places. Fourth hand tools can do a lot of the same things but are a little fancier and more complex by nature.
The late 70s bike boom saw a very large number of bikes produced with centerpull brakes that used fixed-length straddle cables and relatively strong return springs. My understanding is third hand tools were popular then because they're useful in keeping the setup process straightforward, where it can be clumsy otherwise. For example, one can clamp the pads, set the barrel adjuster, pull the cable tight as it passes through the yoke with a fourth hand or pliers, and then anchor the cable.
Another application for them is to help get more precise control over the angles during cantilever brake setup. One of the fundamental areas of concern with canti geometry is the angle created by the point of pad contact with the rim and the cable anchor on the arm as one line and the arm anchor and the straddle cable's point of contact with the yoke as the other. To establish this angle how you want it, you either need a way of holding the pad against the rim or simply visualizing or otherwise "knowing" it. Experienced mechanics tend to get good at the latter approach, but third hand tools can help do it the former way, which is also fine. Using the tool this way you would establish your brake pad position without any cables attached, then apply the third hand, then anchor the yoke on the main brake cable at the point that gets the geometry you want, then dial out the barrel adjuster as above, and finally pull the straddle cable tight with a fourth hand or pliers as you anchor it to the brake arm, then dial in the barrel adjuster. In particular, 90s Shimano and similar low profile cantis can be set up with good results this way by using a 90 degree angle and setting the post extension such that the flat part of the arm is parallel with the rim sidewall. The third hand isn't explicitly needed but it can help give more control for someone that hasn't learned all the shortcuts yet.


New, cheap mountain bike: What's most likely to break?

Information about the specific components would help. I am not sure what will break first, but the derailleurs will probably be the first component to need servicing - especially if you purchased this bike from a sporting goods retailer instead of a bike shop. Brakes will probably be needing some love in the near future. If you ride on trails at all the fork will probably end up needing some maintenance quickly. The wheels will also probably go out of true pretty quickly as well.

One thing you can do to help keep the bike in good running order is to frequently put chain lube on your chain to keep it, your derailleurs, and cassette well lubricated.


How can I warm up/cook food while cycling?

I don't think it would be convenient or practical to use any kind of stove or hotplate while you are actually riding. If you are carrying a backpack or have things on a rack a propane backpacking stove can be very fast for creating a hot meal on a break.

To cook/warm while you are actually riding I think your best bet would be to use a Flameless Ration Heater like you find included in many military-style Meals Ready to Eat (MREs). I think you would still want to assemble the FRH and MRE into a packet and attach them to a rack while you ride because the packaging can get pretty warm.


Should a cross-threaded (but functional) freehub body be considered safe?

Assuming you refitted the lockring correctly, and the threads are now mated up correctly, then mechanically it should be fine.

You should definitely use a torque wrench to make sure its tight enough but not too tight - a well calibrated elbow just isn't good enough for aluminium where the tolerances have been reduced by munching up a turn of thread.

Long term, don't be swapping cassettes unless you have to.  The freehub body might have half the number of refits left that it would have had if undamaged.  But it might be a 90% reduction or a 10% reduction too, depending exactly how much is damaged.

Its possible to "chase" threads to help move material out of the valleys, but it won't restore that material into the lands (high bits of the thread)  Plus a tap that big is uncommon.  Your LBS might have one, but you wouldn't buy one as a home mechanic.


How to register a custom built for Kryptonite's ATPO Program?

From the Kryptonitewebsite,  looks like both the make and model are open-ended text entry forms. So I think you’d be ok to write something like:

Make: Bike-builder’s-name
Model: your-name

So if you had John Jones make your bike and you’re Carla Carlson then you could say:

Make: JJones
Model: Carlson
Model Year: 2020

If you built the frame yourself, then I think you could name it anything you want.
For kryptonite, they need the bill of sale if you bought it or an appraisal if you built it yourself.
Kryptonite is a little famous in being ... slow ... in paying out on their “insurance” so you may be better off just listing your bike on your homeowner or renters insurance policy.
What’s important to remember is that from the perspective of kryptonite, insurance companies, the police, etc is that the frame is the bike for all intents and purposes. So you use the frame number for the serial number of the bike.


Yes, you can use the suggested alternate BB cartridge sizes.

The thread (68mm) has to match precisely, but the width of the axle can vary.  The problem is whether 1mm more or less will affect your chainline on the drive side.  Relatively minor changes can upset the extreme cross chain positions.

So if you're a big-back-cog rider, get the narrower BB, or if you ride a lot on the smaller rear cogs, get the wider BB.


This goes against accepted wisdom, but I think test rides are overrated. Not useless, but overrated.

You're going to own the bike for a long time presumably. You're going to be able to play with the tire pressure, the handlebar position, the seat height and fore/aft, the seat itself, the pedals, the cranks. As you develop cycling muscles, your position on the bike might change a little. If the frame size is "close enough", all of these things can be adjusted to lock it in once you get riding it.

I could give you the same bike with different tire pressures and you would say, "wow, that one was a comfortable ride" or "wow, that was a fast ride". You get it home, change the tire pressure, and all of a sudden it feels like a different bike.

Like sillyyak said. . .some of the important stuff for you is going to be standover height, weight, ability to accessorize. And almost none of that is learned on an actual test ride.

As long as price and model are similar, I think it's a good idea to get a bike at the most convenient shop, or the shop where you like the people the most -- you will be going back there (repairs, clothing, helmet, lights, accessories, etc). I wouldn't rule out a test ride, but just don't use it as the deciding factor. The things a test ride reveals are not necessarily the things that matter in the long run, and can even be deceptive.

Let use know what you end up getting.


I can only answer on the second bullet point of your question:

...may have more rants/raves/discussions on web forums...

Instead of infering this by the production count, you can directly find out how much discussion is happening for each particular bike model.

A simple way is to use Google. For example:

https://www.google.com/search?q=schwinn+letour gives "About 43,800 results"
https://www.google.com/search?q=schwinn+voyageur gives "About 705,000 results"

That definitely means that you'll find more written material on the internet about voyageur than letour.


Front derailleur doesn't seem to be moving

There are basically 4 possibilities:

The derailer is bent.
The derailer is gummed up, has mud in it, or is otherwise being prevented from moving.  (You said the cable has been completely loosened, right?)
The limit screws are misadjusted
It's the wrong derailer for that gear setup.  Eg, a double derailer on a triple crank.

(It is curious that the decal says "8 speed" -- not something you'd expect as original equipment on a 27 speed bike.)

(It appears to be a down-pull style derailer, and it should center over the granny gear when the cable is fully released.)


Why do my tires always deflate between rides?

First of all, do your tyres (tires) lose air at the same rate or are there noticeable differences, one going down faster? If this is the case the last paragraph may explain things.

All tyres lose air over time. However the bigger the tyre the longer it will take to notice the loss. And also the higher the pressure the faster the loss. Your car wheels have the same drop of pressure but because of the bigger volume and the comparatively lower pressure the drop is less noticeable. Still you're always advised to check air pressure each other month.

Pressure drop is mainly due to permeability of the rubber, let's call it like that, of tyre and inner tube which are constants for a specific type of compound. In the late 80s latex inner tubes came to use because they were very light and more resistant to perforation. The disadvantage however was that the pump came into daily use.

The quality of the seal of the valve plays another part. It is quite normal to top up a 25mm racebike tyre @100psi at least once a week. All Schrader (car type) valves have a removable core. For many newer Presta / Sclaverand valves it's the same. To do this you'll need a special, inexpensive tool. For some factory fresh valves the core isn't properly screwed in and may leak. It's always a good idea to check the tightness of the core, it could be a reason for leaks.


It's a bottom bracket bearings preload collar/adjuster. Just like other bearing pairs (i.e. hubs, suspension pivots, headset), bottom bracket bearings need a way to remove slack, so spindle won't move sideways. There's a thread on the inner surface, so when you turn the collar, it will move left/right along the spindle. The bolt fixes the collar in place.

If you are looking for a replacement, I'd measure the axle diameter and collar thickness. If it's 30mm/5mm, I'd try a Race Face one, or contact any Shun vendor and ask about separately sold spare parts.

Some crankarm/BB systems don't use this exact method, and some do. For example, Race Face cinch crankarms have almost the same looking collar:

SRAM has a similar tool as a part of their BB30 and now DUB crankarms:

Sometimes there's not enough space for a collar, so other options to preload bearings are:

Optional stack of flat shims on spindle and a wavy washer, here's a screenshot of Zipp Vumaquad manual, figure 3 shows a wave spring:

Shimano's Hollowtech 2 crankarms use the non-driveside arm bolt to preload the bearings:


Recommendation for panniers used off the bike a lot

You might consider:

Arkel Bug, which works as a backpack. Quite modern, sporty look.
Ortlieb Downtown, which has a comfortable shoulder strap.

You might check other products of those two producers, if you need a bigger/smaller cargo capacity.

Both of these panniers are very easy to attach to your bike. Perfect for your daily commuting needs and running errands.


By far the most reliable way is a visit to the Local Bike shop, find a smaller one with lots of kids bikes and entry level bikes (They know about tight bidgets). It should take less than 5 minutes for them to give you a quick assessment of what needs to be done to make it safe, and most will happily do the assessment for free (especially given they will get a sales of at least 2 tires and tubes)

Tires and tubes - replace.

Wheels - remove from bike and check bearings, adjust if required. If noisy not really a safety issue, but if too loose it is. Check rims for wear from brake pads and big dents. Check spokes for tightness. Check where spokes go into rim for cracks. Ensure the QR levers are tight (They should leave a dent in your palm when you press down to do them up). Check wheels to ensure they are true (Wobble from side to side or up and down) - only a safety problem if the brakes cannot be adjusted tight enough.

Brakes - Adjust so they are tight. Check pads for wear. Lube cables and replace if budget allows. Frayed rear brake is not a safety issue unless the tension side is frayed.

Seat - check seat post is tight and seat bolted on to seat post.

Steering / Handlebars - are all attachements tight (stem, handbars, brake levers and shifters). Do the handles bars turn freely and without play in the head.

Bottom bracket/Pedels - do they spin freely and smoothly without play. Listen for creeks and grinding noises. Look for cracks and damage to the cranks.

Frame - look for visible cracks - its steel so sudden failure is not likely. Go for a ride and jump up and down a few times, listen... Pick the bike up and drop it onto its wheels from about 300mm. Listen to the bike for rattles, squeaks etc. Some are normal, but it can give away a lot.

Rear derailuer and shifters - not really a safety issue unless the chain jumps off and jams. , but do read up how to tune it. Make sure the chain stays on the cogs.


Tyres self-deflating after being in storage

If you pumped up the tubes outside the tyres, you probably didn't pump them up very hard (or they would have gone bang). There probably wasn't enough pressure for them to go down quickly so you didn't notice. On the bike at proper pressure they're going to go down much faster (on top of that you'll notice changes more easily). So you could easily hold 5 psi for two days but not hold 60 psi for a few hours.

A slow puncture can be hard to find even when you know it's there. So it would be even harder to find if you're not certain.

Anyway I'd just get new tubes. If I suspected a puncture from sheer age, I'd be wary of sudden failure (in a different spot).


Using Loctite for integrated head set and bottom bracket installation

As a general rule: if the manufacturer says it's press fit, then it really is press fit meaning it will be plenty tight after normal installation, and also meaning that because of the small tolerances any extra layer (like loctite) will make it harder to fit.

Not saying there aren't exceptions but none of the press fit bike components I ever installed had problems or became loose. In fact before I had the proper tools for press-fitting I just used to hammer the components into the frame and when you do that it is obvious you don't need extra: it takes some serious meticulously aimed hammer strikes to get the cups in. No way they are going to loosen. Same story getting the cups out again: it takes sheer force - but the adequate tools provide this. Just to illustrate you should not need anything special at all for installation/deinstallation.


Fewer spokes doesn't necessarily mean a weaker wheel, there are many many variables to consider. Ideally you have a salesman you can trust, or these wheels are online ( link? ) and there are reviews to read. It also depends what you're using these wheels for, of course, a casual road ride isn't likely to do any harm.

At any rate, if you're stuck with the wheels on the bike, you should just use them until they give you trouble as DRH mentioned.

http://sheldonbrown.com/wheelbuild.html#spokes

What are the advantages or disadvantages of different spoke styles


Make your bike less accessible.  Don't park it near where people walk past.  Instead, park it down the row a little.  Avoid parking it anywhere that will be in anyone's way—inconvenienced people may take it out on your bike.

Park your bike in a secure location if possible.  That means not leaving it outside overnight; ideally bring it into a lockable garage or shed, or even into your home.

Make the accessory securely attached.  That means no velcro, no quick releases, and no breakaway plastic.  A downside: breakaway parts are a safety feature to reduce the chance of stabbing into you or someone else.

Also, look at the fasteners.    If it's a thumbscrew like a GoPro, anyone can undo that without tools.  So look for replacement metal bolts that can be torqued down tighter.  Ideally the new metal bolts would be into metal fasteners—plastic ones may strip out easier.

To protect the bolt, you can use some weird security tool fitment that the thief won't be carrying on their person.   Or consider putting a blocker in, like a ball bearing into a hex socket.  You can retain it with candle wax or glue, annoying to remove legitimately.

Also prevent the bolt being removed by using a thread locker like locktite. Generic superglue/cyanoacrylate glue also works fairly well.  Avoid the threadlockers that need heat to release, else you can't get your own parts off without a hot torch which will melt other things.

An additional thought—depending on how your bike bars are set up, it may be reasonable to wrap your bartape over the accessory fitments.  This will obscure the fastener and make it take longer to interfere with your bike.

Naturally these suggestions won't make your bike theft-proof, just make it less-attractive and take longer to fiddle with.


I changed my V-brake pads but I can't adjust them correctly

If all you did was to unbolt the old pads and bolt on the new ones, adjusting the spring tension should be almost enough.
Each arm has a return spring and a screw for regulating the tension of each one. If one pad touches the rim all the time, tighten the spring on that side and also losen the other one. Do it in small steps (1/2 turn or 1/4 turn each time).
If that does not help, ensure the springs are properly engaged. Many v-brakes have springs that engage a small hook behind the arm and is easily knocked out of place during maintenance.
Disengage the cable from the quick release and check if each arm has a return force that separates it from the rim. If not, the spring is too loose, disengaged or out of shape. (I doubt the spring is out of shape if the brakes where working before. Also, It's very difficult to bend a brake spring while it's assembled)
There are also brake mounts (in the frame or fork) that have 3 holes for the spring to engage, each hole provides a different tension range. But to access that you'd have to remove the brake arms from the fork or frame and reattach. If you did not remove the arms and your brakes where working correctly before, this is not the cause and it's not necessary to disassemble.
Also, check if the cable is pulling the brakes to one side. It is common when the cable is too short or is routed badly or if it's being pushed by an accessory or something else.
It is also possible that the rim is not centered in the fork. (It may be dished to one side, that is, the rim may be true and round, but with an offset from center.) Or may be that the fork (or rear triangle) has an asymmetry so the rim does not sit at the same distance from both brake bosses (the bolts the brake arms are fixed to).
If that's the case, you can place the brake pad's spacers in such way that the pad does not rib the rim permanently. Each pad has two pairs of concave-convex "washers" that allow for alignment adjust. One of the concave pieces is taller than the other and is usually placed "inboard" (between the pad and the arm). As a last resort, you can exchange the taller for the shorter one, which would make the pad sit closer to the arm. Do this only if you are certain that both arms have their return spring properly engaged and that the wheel axle is properly mounted.
Check whether the wheel is properly affixed to the bike (check if the axle is well fastened and that the wheel is aligned with the fork or bike frame)


What are the downsides of a twisted wheel?

You are lucky to have V-brakes, because they make repairing the wheel yourself an easy half an hour task. Plus the tool is $2 usually.

Spokes pull the rim one way or the other (look at the spokes and their angle from the hub flange to the rim). If you tighten a spoke, it pulls the rim away. So, you 1) tighten your brakes barrel adjuster until they rub heavily 2) tighten the 2-3 spokes around the dent to pull the rim away 1/2 or 1/4 turn and loosen the the same amount the spokes, pulling the rim the other way 3) repeat many times, until there is nearly no rub 4) loosen the brake's barrel adjuster to the normal riding setting.

If you don't fix the wheel, it will be easier to get damaged the next time. That's it.


Can I operate more than one motorized wheel from one motor control unit?

I don't think that you can. Each wheel needs its own individual controller and throttle. That is the reason for you never see an e-bike rear wheel tricycle and instead they're always front wheel driven.
Also, if both powered rear wheels on a tricycle were operated by a single controller, you'd have steering problems.


What's difference between 1/2 and 9/16 inch pedals?

The measurement is for the diameter of the pedal spindles, where they thread into the cranks. You need to find out whether your existing pedals' axle is 9/16" or 1/2". If there is no measurement indication on your existing pedals or the paperwork which came with your bike, ask your LBS if they could test out with some existing pedals to find out what size you need.


With a traditional non-through axle, there's a slot at the bottom of the fork (or the dropouts), the axle is hollow, and there is a skewer through axle. You use the quick-release to loosen the grip around that slot to slide the skewer (vertically) in and out of that slot, while it's still going through the wheel.

With a through axle, there is simply a hole on either side, instead of a slot. You remove the axle entirely out the side of the hub in order to remove the wheel.

Typically, through axles are much thicker axles. The thicker axle is stronger and stiffer. Downhill mountain bikers were breaking axles, and it's a lot harder to break a 15mm through axle than to break a 9mm traditional axle. The stiffness also helps the bike handle better ("more responsive").

From what I've heard from a framebuilder friend, the move to through axles is also because frame manufacturing techniques improved to allow them. With a traditional dropout, if the two sides were a millimeter off, the framebuilder could simply file a millimeter out of the slot on one side to make things work right. Once it's all polished and painted you'd never notice. With a through axle the framebuilder absolutely has to get the alignment just right, because an oval hole just won't work.

The only downside of a through axle is that changing a flat might take an extra second or two.


What's the easiest way to add gears to my single speed?

Depending on what you want, you might just be okay lowering the current gearing.  It comes with a 42t chainring and a 16t freewheel, and switching to a 17t or 18t freewheel will decrease your overall top speed somewhat but make it easier to climb up those hills.  If you want to have the option to swap for a harder gear when you're planning a mostly flat ride, you could either install a different sized freewheel in place of your fixed cog (on the flip side) or get something like a White Industries DOS 2-speed freewheel.  In either case, you'd change gearing by loosening the rear wheel and moving the chain position by hand.

If you want to switch to a true multispeed bike, you've got a couple options. Easiest might be to purchase a new wheel built around an internal gear hub.  Your rear dropout spacing is 120mm, and there are a few hubs that come in or can be reduced to near that width - notably the Shimano Nexus 8 Red Band, the SRAM P5, and several of the Sturmey Archer hubs can be made to work.  You could also look into getting the frame cold set to a wider dropout spacing, which would open up more IGH options (the Alfine 8 being a great one) as well as conventional multi-speed cassettes - though you'll need to get a derailleur hanger chain tug, like those made by DMR.


There's two different situations here.

The first time disks are set up after installation can be a lot of work. The calipers need to be fixed in the right position, which can involve a special tool to shave a little off the mounts to get them square and parallel to each other, then some precise setting of the mounting adapters and positioning of the caliper on them. Both can be tedious because you need to do the bolts up quite tightly without letting the thing you're attaching move. If you're unlucky you might even need to bleed hydraulic brakes.

But once that's done it almost never needs to be changed. So "setting up the brakes" means changing brake pads and every year or so either replacing the brake cable and outer, or bleeding the brakes. Neither of those should take more than half an hour, but I'd probably still get a shop to bleed the brakes because it's messy and toxic.

Just changing pads is normally quick, even if you have to turn the bike upside down to pull a wheel out. It's usually ~2 minutes plus the wheel removal Cleaning the rotor takes as long as swapping the pads. Mostly it's just a dirty job. I wear disposable nitrile gloves and just use toilet paper to clean the rotor, but somehow still manage to get road dirt off the caliper on myself every time.

IMO the difference in braking power would make up for any difference in hassle, but I've also found that to keep V brakes working properly takes more work than keeping discs working. Setting V brake pads up is a bit of a pain, and they wear out fast compared to disk pads. But you have to redo the V brake setup every time you change pads, where discs you just push the pads out (hydros) or wind the adjuster screws out (cable). It's quick and low-hassle.


A good bike shop that is a Topeak dealer will likely have parts for the pump. You can visit the Topeak: Where to Buy page to find dealers in your area. Or contact Customer Service - they may just send you the parts for a minimal shipping charge or free; other companies have done that for me in the past.


As a bicycle mechanic in the Netherlands, I always advice not to use a waterhose. Rain doesn't get into your bearings and chain, while water from a waterhose sometimes does get in nasty places. I sometimes see chains or even a bearing which is rusted because the oil/grease is 'hosed away'.

You can safely use water out of a bucket, with a sponge. But do not use a hose. Especially not a high-presure hose!

The best thing to do is clean the bicycle entirely with some cleaner without grease. Based on silicon for instance. Spray it on the bicycle, and clean the bicycle with an old cloth.

Grease your chain again. And grease all metal parts (bolts and stuff) with some thick grease such as vasaline.


Does anybody use an under the saddle bag for touring? (Not Pannier Bags)

I have seen similar setups for MTB touring that use a large seatpack, a frame pack and a handlebar pack to get enough capacity. This setup also allows a better weight balance.

Bikepacking.net

is a good site for getting ideas for different setups. This site might also give you some ideas as well. I know we aren't supposed to recommend gear, but I've been very happy with the stuff I have got from Revelate Designs.

Revelate Designs

IMHO, your concerns about panniers are unfounded if you plan to tour on anything like a road. Panniers can be a problem if you are touring on trails or your bike geometry doesn't provide sufficient heel clearance ( often a problem on MTB bikes)


The 622 x 19 is the rim size. 622 refers to an ISO 622 (700c or 29" in mountain bike parlance) wheel. 19 refers to the rim width in millimeters.

The 28x1.75 is 700c x 45 tire size (or equivalently a 29 x 1.75). So, you need a tube suitable for this size. Tubes are sold by ranges, but it's not hard to find a 700c x 28-47c tube (this is what Schwalbe sells). You can also use tubes marked 29" x (some range containing 1.75). If you go to a bike shop and ask for either a 700c x 45 or 29x 1.75 tube, they should have you sorted out in a few seconds.

The 700c = 29" thing is usually 700c for road/hybrids, 29" for mountain bikes but its the same wheel size. Confusingly, another name for 700c is 28". Why? Aliens.

As Criggie points out in the comments, make sure your tube has the right kind of valve. You could take your old tube to a shop and they'll sort you out. Or the bike.


Why does my rear cassette feel like it's jumping when I put pressure on small cog?

Those teeth are severely worn, just by visual inspection. Try a new cassette, chain rings, and chain. (Don't try changing just one.)

It could have been the grime that was holding the worn system together, and when you cleaned it all the play now shows up. In the future, if you replace your chain more often you can make the chain rings last longer.


Gearing preferences of men vs. women on road bikes

Really this question is far too broad, but I'll mention some things that dictate gearing, ultimately, non have anything to do with sex or gender.

Strength - Stronger people can push heavier gears
Cadence preference - someone who prefers a higher cadence might choose gearing for quicker pedaling
Terrain - Hillier = easier gearing, flatter = bigger front and smaller back
Type of road cycling - TT will use harder gearing, endurance racing lower
Compete vs training - Some people have different bikes for training and competing

There's other factors too, and as most sports, there is a difference between top male and top female competitors and I'm sure it will be something like top males might have larger front rings than top females. Although the difference within the male and female groups might be of more interest than just the difference between avg male and female.


Is there a polite way to take the centre of the road without antagonizing motorists?

In my experience, no. The problem is that however polite you try to be you're taking the lane so you're in their way.

My commute takes me over a narrow one-lane-each-way bridge that's a bit of a choke point, so it's busy. It's also a raised bridge, so sight lines are very poor. Since I ride it twice a day I've had the chance to experiment with some different approaches. Normally I ride during daylight, so I'm only considering that at the moment, but I have dynamo powered lights that are always on (they don't flash).

1: ride normally, take the lane
Result: most motorists are fine, perhaps 10% follow closer than I'd like (within 3m), occasionally one will (illegally) overtake, often failing to allow the 1m separation that I like, but since I have room I simply move away from them.

2: ride "politely" as close to the side of the road as I can
Result: 5-10% of motorists try to squeeze past me, often pulling back in before they have actually done so and forcing me to brake to avoid being hit. Some of them are aggressively close and these are the only times I've been abused.

3: take the lane, but turn my daylight-bright blinking lights on
Result: very few motorists follow too close, only one overtaking motorist and that was when there was clearly no oncoming traffic (still illegal, but relatively safe)

4: ride on the (narrow) footpath
Result: rather than being scared of misbehaving motorists, I'm now illegally terrorising pedestrians (of whom there are quite a few). I've only done this a couple of times, both because the road was packed with cars and I really didn't feel up to fighting for my place on the road. I don't feel good about it.

5: take the lane, lights on, helmet camera
Result: sore neck, as for (3) above.

I've basically stopped experimenting with this because the results are, in my opinion, conclusive. I turn my lights on when I leave the bike path a couple of hundred metres before the bridge (bright flashing lights on the shared path are, IMO, rude and unnecessary), or when I leave home (the bridge is ~1km from home). So I'm always using the flashing lights when I'm on the road.


What is the diameter of Lizard Skins Logo and NorthShore grips?

The Lizard Skins Lock-on Logo grip is 31.06mm in diameter.

The Lizard Skins Lock-on North Shore grip is 30.94mm in diameter.

Both were measured using a digital caliper, and assuming a small difference in diameter due to texture, they are nominally 31mm diameter grips.

The thinner Lizard skins grips measure approximately 29-30mm, again depending on texture. For instance, the Peaty measured 30mm, and the Charger measured 29mm, but was difficult to get a consistent measurement from because of the type of surface.

I hope that helps.


When you are braking you are putting quite some load on the frame where the brakes are installed. (Newton's 3rd principle of dynamics: to each action corresponds an equal reaction with same intensity and opposite direction)

If the frame is not designed for this, you are aiming for disaster.

So, if the fork was not designed to have disc brakes installed, don't do it.


Are there any bicycle computers that will log ride data?

Garmin Edge-series computers coupled with Garmin Connect ... not inexpensive, but have traditional bike touch points (wheel and cadence sensors) coupled with GPS, logging and USB. Edge 205/305 are BW, 605 and up add color, ANT integration, etc ... all the modern bike computer features.


Can I use silicon spray to lubricate my hybrid cycle chain?

Can you? Yes. It is not optimal for use on chains though. It washes away rather easily leaving your chain unprotected and un-lubricated. It would work in a pinch but a light oil or something specifically made for the application will work much better and last a lot longer.

Wet or Dry lubes depend on the riding conditions and where you live. WD40 makes a good bicycle chain lube, their bike line, not the generic stuff in a can. Don't use that. RocknRoll, Triflow, ProGold all also makes good lubes.


adding bullhorn handlebars, what about shifter and rear derailleur?

We don't do product rec here, but I will note that SRAM rear derailleurs are compatible across road and mountain groups for 9 speed, as are Shimano.

So, if you have a Shimano rear derailleur, buy another Shimano shifter and keep the existing derailleur (or Shimano compatible, e.g. from Microshift). If you have a SRAM rear derailleur, replace Shimano with SRAM in the last sentence and ignore the parenthesis.


That does seem small for your height. Are you hunched over while riding? Does your leg stay fairly bent all the way through your pedal stroke? Are you comfortable after riding for a few hours?

The preferred bicycle size depends on more than just your height, and is best figured out by going into a bike shop, getting some help from the staff, and trying out a few bikes.

Ideally: You want to have the seat up high enough that at the bottom of your pedal stroke, your leg is just slightly bent, similar to how your leg naturally works when you walk. You want to be able to bend forward at the waist a comfortable amount that you could hold for hours, put your hands forward into a natural-feeling position, and have the handlebars right there. You don't want to have to 'reach' for the pedals. You don't want to have your knees bent too much. You don't want to be hunched over. You don't want to be stretched out. You don't want to be leaning on the handlebars. You want to be comfortable.

It's not just your height that affects what size bike you want. It's how long your legs are, how long your torso is, how long your arms are, how flexible you are, and how much core strength you have.

2 people that are both 6'2" may have very different proportions (long legs with short torso, short legs with long torso, or anything in between) have different sizing needs.

Generally, bike size affects both how long the bike is (from headset to where the seatpost goes), and how tall the bike is (from pedals to where the seatpost goes). Both go together.

There are 3 contact points: pedals, saddle and handlebars. You can't really move the pedals, except to get slightly different length crankarms. However, you can get a longer seatpost, seatposts with different amount of setback, and you can move the saddle around a fair bit. You can also get different stems and different handlebars to move the handlebars around quite a bit. All that means that for a bicycle that's only a couple sizes too small, you can probably still adjust it to give you a reasonable fit.

With an MTB that's ridden off-road, you may want a frame that's a touch small, so that when you fall with the bike between your legs, your feet can hit the ground well before your crotch hits the top tube.

In other words: can you get the fit right on this bike? If it feels good to ride for hours and doesn't give you any pain, it's probably fine...


Mountain bike tyre at road bike pressure

2.00 or 2.20 or 2.30 inch tyre that I would use at 7-8 bars (100-120 PSI)

Does such a tire exist?
No.
A little math...
The surface area of a torus is 4 x pi^2 x R  x r, where R is the large radius of the wheel and r is the radius of the tire here.
Let's put a 2.00 tire on a 29er rim...
4 x pi^2
  x 15" (approx radius of wheel at center of tire cross section)
  x  1" (radius of tire's surface)

= 592 in^2

Assume the tire surface area is only about 2/3 of that, or about 400 square inches.  (It's probably more...)
Pump that tire up to 100 psi and each of those 400 square inches of tire surface has 100 pounds of pressure pushing on it.
That's a total of 40,000 pounds of force trying to push that tire off the rim.
Even if the tire can hold, the bead of the tire will be pushing HARD against the rim, trying to tear it apart.
40,000 pounds of force for a 2.00 tire at 100 psi.  Pump a 2.40 up to 120 PSI and it's more like 50,000 pounds of force.
There's a reason why tires have maximum pressure ratings, and larger tires have lower maximum rated pressures, and it's not because higher pressure starts to increase rolling resistance.
It's because high pressures in a large tire are downright dangerous.


I can think of six possibilities (however realistic each may or may not be, and not in any particular order) for crank advancement through an angle out of proportion to the driven wheel in a fixed gear setup...

(1) 24TPI hub threading not fully bottomed by the cog as it should be.  The reverse-thread lockring, if all parts are truly tight, should prevent this altogether, but tightening the lockring would not necessarily ensure the cog is bottomed against the hub shoulder (since the cog won't cooperate by going ahead and tightening [like axle cones often do] if the lockring is tighened against it while loose).  I have not experienced this, but since the lockring has a left-hand thread, I assume it could be loose from the cog without immediate catastrophe.  The cog would then be allowed to rotate on its screw threads through a small range, but it could not completely unscrew because of the reversed thread conflict.  The scenario provides that the cog is intermittently screwing back and forth between 2 shoulders (and both ends of this range might feel like freewheel threads being tightened [with alternating direction] when torque application is reversed).  Hypothetically speaking, a same-threaded locknut would not do this, but rather be free to unscrew by the impetus of the next nut over (which would be the cog), and the results WOULD be catastrophic.

This seems pretty possible to me.  If I install a freewheel by hand, even using a chain whip, I can still feel it tightening when I start riding and get my weight and leg muscles into it in the normal drivetrain usage.  This suggests that if a fixed cog were applied using only hand strength, and then a lockring were immediately applied, perhaps that final tightening takes place after the lockring is set, and since post-tightening of the cog causes the "nuts" (cog and lockring) to be DIVERGENT, there would be room for what I described since it would be free (enough for leg power at least) to untighten from the hub and tighen against the lockring under back-torque.  Assuming you have brakes, my suggestion is to use leg force to tighten the fixed cog and stop with the brakes (or whatever it takes to avoid any backpedaling) and then re-tighten the lockring and ride as normal to see if the problem goes away.  Without brakes, find a way (like do it uphill, or use impact if you can fashion some kind of boss or linkage to the cog) to maximize tightening torque before the lockring is finally snugged.  Make sure the threads, as well as the faces of the cog and lockring, are clean and there are no spacers or anything but hard surfaces for bearing the torque.

(2) I have not heard of this happening other than in my imagination, but it seems pretty conceivable that perhaps the soft male threads on the hub have worn [stripped] sufficiently to allow the driven cog to skip over them under sufficient torque.  This would be more likely if the bike had previously been ridden with the rear cog and lockring inadequately tightened.  This would effectively require hub replacement in any hub I have seen (where the male threads are a permanent and fundamental part of the hub body.  Even just short of tight, there is often noticeable play in these threads, which is why I imagined this possibility.

(3) Chain skip, which I think was hinted above would require a pretty extreme pitch mismatch in a single speed train in order to ride on the tooth peaks without trough engagement.  It's a remote possibility, and you would probably hear an ugly metallic racket as this took place.  Moreover if your chainline is imperfect, this could easily result in a thrown chain.  edit:  If this is possible it would imply that the chain is already WAY too loose.

(4) Tire slippage is possible (however unusual in an inflated tire), and might feel a little like thread friction (also being a quiet phenomenon).  I have seen tires [that don't have much "gum" over the carcass material in the bead area] with low inflation be able to slip on the rim under torsion.  Not much of this would be possible before damaging the valve stem if the tube goes along for the ride, but if it stays with the rim (less likely), the tire could slip infinitely.  Most tires stick pretty well but I have seen exceptions.  This is the reason for rim-locks in fat low-pressure tires.  A test of increasing inflation should eliminate this possibility.

(5) I have definitely experienced a type of crank wear that could feel like this (but only for your left foot).  In conventional square-splines, if you do a lot of standing, jumping, etc., with your right foot forward, the torque in the spindle is reversed from normal pedaling action by any downward force that ends up evenly distributed between both pedals (as in, coasting NOT pedaling).  (Keeping your left foot forward as a general rule when standing negates this possibility)  The soft square-taper-broached holes in the crank arms can develop play on the spindle and then the left crank is allowed to swing through a dead angle (relative to the right crank's constant chain engagement) that may feel similar.  In very minor cases, the spindle cap screws or nuts can be tightened down harder to "cold-form" the crank arms (they're pretty much toast by this point anyway but you can get home on them by doing this).  In more advanced cases, I have used a piece of an aluminum beverage can to shim the tapered hole and hard torque to remedy.  Ultimately the condition necessitates crank replacement.  *edit: I think this problem is more likely with the older "nut-on-stud" crank attachment to the spindle since the serrated side of the nut reacts to any crank movement and provides a quick foothold for development of slop.  I changed my habits away from having my right foot forward while standing at about the same time as I started using a cap-screwed (rather than nutted) bottom bracket, and I have not had this problem since, so I'm not sure how likely it is in other cases.

(6) Backlash from chain being too loose.  The chain should always be loose enough to not be taut at the tightest point (found by rotating the system until the minimum chain play is found - play adjustment should be made at this rotational position only).  If there is eccentric wear or manufacturing fault in either sprocket, this could be more extreme but there still always has to be at least slight play.  If the variance is extreme, then at the loosest rotational phase of the system, there would be considerable backlash, the 'dead angle' which the cranks must subtend between application of forward and rearward torque (regardless of rotation position or speed - it's the transition from the slack being at the bottom run of the chain with forward drive to it being at the top run of chain with rearward drive, regardless of actual movement).  This would not feel "frictional" like the hub thread tightening phenomenon, but more like a free angle between abrupt endpoints, like when you switch from coasting to pedaling on very coarsely pawled freewheels or freehubs.


Your bleed was probably not perfect. It is normal. Pulling a perfect bleed is a bit hard for first timers.

Possible reasons for a not perfect bleed:

you did not fully reset the pistons before starting the procedure
you did not apply enough negative pressure and move oil from one syringe to another many times in order to remove all the air bubbles
you did not bleed the lever (push the lever all the way in and apply negative pressure on the syringe on the lever)
you introduced some air (and/or lost oil) between the time you removed the syringe and fitted the torx screw back in
you introduced air from the sirynge accidentaly (a bit rare)

My suggestion is to rebleed (not fully, but just enough to remove the air). Push oil from the bottom (caliper) using a 90% full syringe and pull from a 10% full syringe from above at the lever. While doing so, stop pushing from the bottom and continue pulling from above to apply negative pressure. You'll probably see 10-15 bubbles appearing at the top syringe.


How can I treat an aluminium frame ready for restoration?

There's a few approaches you could take...

I'd say that getting it blasted should be the first step no matter what as chemical strippers can damage alloy frames are very messy and really bad for the environment.

Give it a polish with some very fine grit wet/dry paper to polish up the alloy.

Then you could use one or a combination of the methods below to get the kind of brushed look that you are after. Whichever gives the desired finish the best.

Tip Get a scrap piece of alloy to test brushing technique on before commiting to attacking your frame. (if you mess up badly you could always reblast or repolish the brush out of it.)

Option 1. (carefully) use a wire wheel drill bit go over your frame

Option 2. by hand with a scotchbrite / scouring pad to go over your frame to get the desired brushed look

Option 3. 000 or 0000 grade Wire Wool then carefully do long straight strokes down the frame.

Once happy with your finish don't get fingerprints anywhere on the finish or they will show through the lacquer.

Clear lacquer the frame locking in the brushed finish. Thin laquer = no drips

Depending how shiny/durable you want the lacquer increase the amount of coats and let it completely dry. Polish with a clean microfiber cloth between each coat. repeat until happy.

Hope that helps.


Don't make your frame water tight. That will only make your problem worse.

It's unfortunate to see a frame go bad due to internal rust, but it needs to remain unsealed.

The reason for this is that moisture will find its way in and needs a way out. Even if you never ride in the rain, condensation of water vapor alone will allow liquid water to accumulate inside the frame.

Most frames (I believe) have small drain holes near the bottom bracket for this reason alone.

Here's a nice little post from Gunnar about why their frames have drain holes:
http://gunnarbikes.com/site/2012/06/draining-your-bike/


Mudguards (typically called fenders in the US) are a great feature and come in many varieties. The fenders you have are full-coverage fenders and are likely aluminum. Metal fenders are still quite common (and in my opinion, fenders are an essential addition to any bike if you live where it rains. Velo Orange manufactures many sizes and styles that are affordable.)

The fenders are held to the bike via fender stays (long aluminum rods) and are mounted directly at the fork crown in the front and the brake bridge and chainstay bridge/bottom bracket shell in the rear.

Fender stays are usually mounted to threaded bosses (with an M5 or M6 cap screw) integrated into the front and rear dropouts (or near the dropouts.) In situations where you don't have dedicated bosses, you can use p-clamps to mount them securely.

At the other end of the stay there is a nut and an eye bolt which allow the distance between your tire and the fender to be adjusted (10mm minimum!) Note: There are many different methods for attaching fender stays, but this is what your fenders utilize.

To install, you simply put the eye bolt onto the fender stay, push the threaded part through the hole on the mounting tab, and tighten the nut down to secure the stay. Do everything loosely at first, then adjust the distance from the fender to the tire and center it.

Here is a link to an online vendor, but most bike shops will have this hardware on hand.


Can anyone identify which Specialized Diverge model this is? It was built in 2017

That's a 2016 bike I think. The 2017 models did not have the kink in the seat stays.

I'm guessing it's above the 'Sport' Level (equipped with Sora), and below the 'Comp' (105).

I'd ask the seller if they bought it new and if so if they have a receipt.


Bike broke, strange parts came out, and doesn't know where to find exact replacement

It is a derailleur pulley, and fairly worn out one at that. The easiest way to find a fitting replacement is to buy a set from an aftermarket manufacturer that comes with adapter shims for different derailleurs. You can simply try different shims until you find the one that fits.

They do come in different teeth counts. From the picture it looks like this one used to have 11 teeth.


Front derailleur cable tension too high with Acera shifter and Ultegra derailleur

I just figured it out... the front derailleur cable wasn't going over the leverage tab on the derailleur correctly.  I had it going under and that's why there was no leverage going into the largest chain ring.  Here is an image of what I mean by leverage tab:

http://hostelshoppe.com/PDF/ftder_cable_routing.pdf


If I understand your problem correctly it is the drive side that is stripped while the non-drive side (left) is still usable

Depending on the frame (i.e. it's value for you) and the bottom bracket type I see the following solutions:

get yourself a cartridge bottom bracket (with sealed bearings) and glue in the drive-side plug. You will still be able to replace the spindle and the bearings and the pre-load is adjusted with the non-drive side anyway
get this Velo-Orange bottom bracket for stripped shells
have the shell re-threaded for a slightly larger thread, e.g. BSA shells can be re-threaded for Italian threads. You then need new cups or complete (cartridge) bottom bracket
clean the shell and press in another shell with healthy threads, most likely of smaller diameter
get another frame with healthy threads

Please, give some more information on the frame you have, we can then come up with some specific advice.


The answer to this question is different if you are going on a long-distance tour rather than going-to-work-and-back.

If on tour and facing the prospect of a struggle to do 30 miles when you really wanted to get 100 miles in (e.g. to get to next camp-site) it can be a better idea to not bother, sit out the wind and have a go later that day/evening or the next day.

It is also important to understand weather a little bit. The air in a valley will heat up on a sunny day and, as that air expands, it has to go somewhere. This can lead to a tough headwind instead of an easy down-hill ride when going into the valley. This process works in reverse, so, if planning a long distance ride and crossing valley systems it can be best to book a room in the town at the bottom of the valley rather than pitch a camp at the campsite near the top of the mountain pass.

Weather generally is more active during the day than at night so the best times for avoiding wind in a known windy place are early mornings and night. Clearly this does not help if you are doing 9-5 but if you are doing other shift patterns then you might be able to choose your shifts so as to get a near-guaranteed tailwind in both directions, to work and to home.

If you have to ride into headwinds there are a few things you can do:

Think of wind as water and imagine where the 'river of wind' is going to be slowest. in the middle of the road the wind will not be slowed down, by the edges it will be slower, albeit marginally. Hence, try to ride safe-yet-close to available fences and walls. in that way you will 'not be swept away by the current'.
The sea also has an effect on wind - if following a coastal route try to find a route further inland. The sea heats up differently to the land, this will have seasonal affects on prevailing wind direction. Also bear in mind that most winds are from the west due to the turning of the planet.
Try to be as aero as possible - keep your elbows in.
it may not be full-aero-tuck, but, elbows in will make a difference to your overall drag. You can also hold your handlebars a bit more in-board than you would do otherwise.
Roll with the punches. If there is a gust of wind that is going to stop you in your tracks then you can ease up and put your pedal effort in when the gust has passed by.
Make sure you are not wearing a big balloon. A skirt or a coat can act like a giant parachute - not what you need. Much like how a parachute has a hole in the top to let the air out without undue turbulent effects, make sure your coat has an exit hole for the air driven in through the front.
Be seated. When out of the saddle you present a bigger frontal area. Use your gears rather than getting out of the saddle to get your momentum up.
Sit low. Tiredness helps to 'fall over the bars' and have a flat back. Pretend you have been riding all day and adopt the flattened pose that you get then, with your legs spinning and your upper body relaxed.
Draft anything you can - other cyclists, motor vehicles such as buses pulling out can give small bits of aero benefit.

If the problem is persistent on your route consider getting a 20" wheel folding bike. This will have better aerodynamics than your MTB/hybrid, you can also fold it up and take the bus/train as far as you can towards your destination. Also consider a saddlebag rather than a rucksack/panniers as saddlebags are the most aero bag option.

If the headwinds are always against you and your job matters more than your home, consider moving to the other side of town so your commute is with the prevailing winds rather than against them.


What do I need to know about Turbo Trainers?

That they are booooooooooooring and that you'll sweat a lot.

Also, I'd buy specific tires such as this because they really eat the rubber.


Burning smell?  Stop riding the bike immediately!

Inspect your bike closely and identify what is rubbing.  I'd suspect the brake pads, or possibly a tyre is rubbing on a part of the frame.

Another cause that exacerbates a burning smell is animal urine on the brakes.  Leaving your bike outside means it could be used as a toilet target.

Also look closely at your front tyre.  Spin the wheel and see if there is a flat spot in the tyre, or if the rim is damaged.  Also look for rocks/pebbles stuck in the tread.   Check your tyre pressures too - if they're low that won't help.

I wonder if your bike has been out in the super cold for a bit longer than you realise.  Even leaving it covered, the bike will deteriorate fast.  Consider parking the bike inside a house or garage instead.   Under a porch or carport roof is better than out in the open.


Yes, the body of the brake that holds the pistons is called the caliper.

The thin metal is a spring that keeps the pads help up against the pistons. It should be there.

First, make sure the caliper is actually aligned properly. Try looking through the caliper to see if the pads are touching the rotor. A bright light and a sheet of white paper held behind the caliper can help you see gaps between pad and rotor. Have a look at the Park Tool video below for how to align the caliper.

If both pads are touching the rotor the caliper the pistons may have been pushed out a little too far. This happens if the lever is pulled when the wheel is out of the bike. Take the pads out and push the pistons back in using a flat head screwdriver or tire lever.

Another possibility is that the pads are so new they simply need wearing down a little. You will need to break the pads in in any case. Here's a good procedure for doing that: https://www.bikeradar.com/us/gear/article/how-to-bed-in-disc-brake-pads-31337/. Break the pads in then try re-aligning the caliper.


I suspect the only way to get a certain answer to this is to contact your countries Merida distributor:

https://www.merida-bikes.com/en/p/about-us/distributors-worldwide-139.html


Usually at the "Cut out" in the top of the seat tube, they measure a little bigger than the actual size of the post. I'd say your best bet is to try several sizes at your Local Bike Shop, there even used to be a tool to measure it, but it's rather hard to find these days.  If I had to guess, it's probably a 27.0 or 26.8 just judging by your measurement.


The only question I would have is if the bike is Carbon Fiber or not. I'm guessing it's not and is an alloy (metal) bike. Just like cars, there are tons of stuff people will try to sell with magical properties. Ignore them.

There are two greases I use: The first is because it is everywhere, cheap and easy to apply thanks to the tube:

If you want more grease for your money, you can't beat Lucas Marine Grease:

In the end either will do the job very well. The marine grease is longer lasting and theoretically more rust resistant. But I use it because it does the job well, a tube lasts forever (use a plastic spoon to dig some out when needed) and it's thicker than Park's stuff.

I carry the Park stuff with me on a mobile job because it is easy to apply and customers like names they recognize.  The cost is the same for either. I'd vote for Park due to convenience.


The bolt of my pedal's crank arm broke, what could be the causes?

The "bolt" that broke is not a part of the crank. Your bike has a so-called square-taper bottom bracket and one side of the axle broke off. This axle is a solid metal part that runs from one crank arm through the bottom bracket shell to the other crank arm. It cannot be serviced and should not break. The most likely reason is metal fatigue.

You'll have to buy a new bottom bracket if it is a cartridge type or at least a new axle if is the cup-and-cone type.


1980's bike vs New(er) Models? (Should one stay with an ancient bike?)

I suggest that you go to your local bike shop and see if you can test ride a modern bike.

As Daniel says $500 will not get you far. A test ride of a couple of bikes at different price points will help you decide. You may find that your "retro" bike is OK after all. Or maybe that it never did fit you properly. But a new bike could be 5kg lighter than what you have!

Now is a good time to do it, because it's Spring there and the shops will have a good range. If you decide to buy, then you can save for the next six months :-)


Can I change rotor size with disc brakes?

Rotor size is determined by the brake mount adapter.
So everything else ie. the caliper - stays the same. Only the Adapter changes.

You must check your fork manufacturer for the maximum size of rotor the fork can be safely operated with.

Also check frame clearances (at the rear) for enough clearance for the size of rotor you are selecting.

Going up rotor sizes is specifically for more braking power.


Kenda cyclo cross 27 x 1 3/8 fit on 27 x 1 1/4 rim?

You can confirm tyre fit using the ETRTO spec, which should be specified on the sidewalls of your Kendas and the tyres that were previously fitted.

the format is

ww-ddd

where ww is the nominal tyre width (often measured at the widest point when fitted to the manufacturer's test rim, rather than at the tread) in millimetres, and ddd is the bead diameter in .

I would expect a 27 x 1 1/4" tyre to be specified 28-630.

According to Sheldon, there is no other standard bead diameter using 27" as its nominal measurement, so any "27" tyre is likely to have a 630mm bead. 1 3/8" is equivalent to 35mm.

I have not previously encountered any cyclists using 27" wheels for cyclocross. I assumed "700c"/622mm to be panacea for all but the shortest of CX competitors.


If the rear Auriga used no adapter for a 160mm rotor, the new M800 won't need one either.

Post mount frames can be understood to have a "native" rotor size, the size of rotor that a caliper works with when mounted without an adapter. For some bikes that size is 140, which would mean you would need an adapter, but it's mostly road bikes where you see that, not a hybrid or mountain bike that would be more likely to come with the brakes you have. Likewise some rougher stuff MTB bikes start out at 180 in the back and can't run a 160.


Does MTB tyres wear off fast in City - gravel pavement streets, city road?

Yes, absolutely. The knobs will get rounded off at an accelerated rate, particularly down the center of the rear tire, and the tires won't offer as much traction off-road. This doesn't happen instantly, but it will happen soon enough on a knobby used for primarily road riding.


Occassionally Dropping Chain On Downshifts

From the way you describe the problem it seems less likely to be one of the common mechanical causes, like a stiff chain link or bent chainring. I have two guesses as to the cause. One is a subtle mechanical problem that requires the right conditions to set it off. The other is about technique.

The rear derailer may not be taking up enough slack when you're in the small chainring. (This is not always obvious.) If you happen to shift around the time you hit a little bump or dip, or while you throw your weight forward to stand, or while you adjust your cadence, the slack chain gives a bounce and off it comes.
You may be shifting improperly on these rare occasions. If you shift to the innermost chainring while you're in the outermost cog, and the chain line is angled too sharply, off it goes. Also, to reduce the odds of dropping the chain, a front shift ought to be done like this.


Average speed depends a lot on various factors.  But, having said that, 8km/h is very slow for a fit young person: it's not a whole lot more than walking pace.

Where you're cycling. In cities, it can be hard to cycle quickly. Cycle paths often have lots of pedestrians on them; roads often have lots of junctions, stop signs and traffic lights. If you're constantly having to stop and get going again, that will bring your average speed down a lot.

You say you're in a hilly city.  Going up-hill is, of course, slower.  However, on average, you'll go down as many hills as you go up, so that should balance out to some extent. If you mean that you average 8km/h up the hills, that might not be at all bad, depending on how steep the hills are!

How you measure speed. If you just compute distance travelled divided by time taken, then you're including all the time you're stopped in your average: if you cycle at 15km/h for ten minutes and spend five minutes stopped, your overall average would be 10km/h but, when you were actually cyling, you were doing 15. If you're using a cycle computer or GPS app, you should set it up to only compute average speed over the time you're actually moving.

How you cycle. Obviously, if you don't try to cycle fast, you won't be fast. Are you working quite hard when you cycle, or are you just drifting along? Do you get out of breath? Are you using your gears properly? A lot of beginner cyclists turn the pedals very slowly in much too difficult a gear, and it's hard to go fast that way (and very hard to accelerate away from a stop). As a rough guide, if you're pedalling at less than 60rpm on flat ground (i.e., pressing your right leg down once every second), you're pedalling very slowly and you should probably aim for something more like 75. Use an easier gear to compensate and, crucially, if you feel yourself slowing down, change into an easier gear. The point of the gears is that they let you keep the pedals spinning at a good rate whatever speed you're actually going at.  A good way to measure how fast you're pedalling is to use the internet to find out how many beats per minute there are in some songs you know, and compare that against how often you're pressing down your right leg.

How well your bike is set up and maintained. Many beginners have their saddle much too low. An easy rule of thumb is that, when you're sat on the saddle with your foot on the pedal at its lowest point, that leg should be almost straight. If your saddle is much lower than that, it's really hard to generate any power. Is your bike well maintained? Do the wheels spin freely? Are the brakes rubbing? Is the chain properly lubricated? Does the bike make noises while you cycle?


Grand Tours - Total Ascent (By stage, particularly the giro)

I have found a site with a user who appears to have gone to considerable effort to plot and upload many stages of many tours, including Tour De France 2013 and Giro D'Italia 2013 and many others.

You can view his list here:

http://www.gpsies.com/trackList.do?username=Daniano

From my sampling, they appear to be pretty accurate, but, they are not official.


I'm very skeptical that an internal fault in the hub is causing the external mounting of it to loosen up... unless you are experiencing frequent total rear wheel lockup and skidding, maybe. I have a SRAM P5 hub that I built into an old mountain bike myself. Originally I ignored SRAM's torque instructions for the rear axle nuts and just tightened them by judgement. I have rebuilt car engines this way in the past, with no problems. But after having my rear wheel loosen up, I got out the SRAM specs and a torque wrench. Let me tell you, they specify cranking those nuts A LOT tighter than I would have thought, or dared to do without the torque wrench.

I'm also skeptical that nobody in Denmark fixes internal-gear hubs. Never been to Denmark, but thought bikes with such hubs were very popular out that way.


Reassembling a headset without documentation or notes is truly frustrating.
The plastic split ring is likely a compression ring which is jammed between the steering tube the top bearing,  if it looks like this:

Otherwise, it is a seal.
The compression ring does not have to go in easily by hand and is usually driven into its final position when tightening the complete assembly with a star nut bolt.
The rubber washer is likely to be a seal, but where it comes from is impossible to say. First of all, you need to determine if it came from then lower or upper half of the headset. Then you can try to find a position where it makes most sense (i.e. where it can prevent mud from entering the headset).
Good luck!


Novice: can I replace this bike trailer clamp with an axle one?

I had one of those - it was convenient because it could clamp onto most bikes, but it always came loose over time.  Once it fell off the chainstay completely, and only the safety strap held it.
So I bought a generic trailer hitch from a local bike trailer builder and used that.  I had to shorten the drawbar by quite a lot to keep the trailer in-line with my bike.  Otherwise it was just careful drilling and cleanup of the burrs, and bolting it all together.
Also I had to fit the towball part to my bike and to any bike I wanted to use as the tractor.  So I bought three, fitted one, have one screwed to a stake for times when I want to mount the trailer somewhere stably, like a bike fixup.  The last towball is spare to loan, if someone wants to borrow the trailer.

Here's two pictures of the coupling.  Its essentially two strips of metal that straps around two sides of the round drawbar, and across the end to provide somewhere for the main bolt to attach.

There's one big grade8 bolt that passes through the end cap and is  firmly retained by a nut.  Further down the thread is another nut which is free to rotate, which allows the trailer to twist WRT the bike.  It won't come off unless the trailer did 20 full rotations.
The up/down and left/right motion is taken up by the towball in its cup.  THere's perhaps 30 degrees of motion up/down and the left/right is limited by the rear wheel/drawbar touching.
Finally the towball is retained in the cup by that sliding cap, which can pull back under hand pressure to allow the ball through into the recess.

The towball on the bike looks like this - its a steel angle plate which goes under the axle nut, and that holds the ball/stem piece.

This is a photo of the towball plate on the bike.

Its a 20" wheel trailer and so is the bike, so sits flat.  If I tow with the bigger wheel MTB then the drawbar ends up pointing upward a little.

A good hobby machinist could make something like this up.  I'd just buy the bolt and nuts.  The hardest thing is drilling/milling and tapping the end piece, and getting the hole to suit the towball, and turning the towball on a lathe.
I have towed a trailer+load of 100 kilograms and the towbar worked fine.  That weight managed to slightly bend a wheel axle though!


How to get slower gearing on a 1x10 drivetrain

I recently looked at my 3x10 setup, with the view of going 1x. I decided to stay 3x10 as the 1x10 is a can of worms. The only other practical option was to convert the whole lot to 1x11. With 32->11-36, on the flat 32-11 I spin out a little, but am not strong enough to push 32-36 up the local hills.

What to do will significantly be dictated by the specs and components already installed on the bike in question (In this case Shimano), but ultimately, 1x10 is never going to make a great bike for less strong riders. The 10x (from Shimano, and I also think SRAM, some correct me if i am wrong) is not made for larger than 36 tooth rear cluster. The 11-36 range is not enough for many riders in hilly terrain.

Lower gearing comes from a bigger rear cog, smaller chain ring or smaller wheels. In this case, you are looking at 27.5", smaller wheels are not going to make any real difference.

You can extend max cog size of the standard Shimano 10x derailleurs (Not sure about the M610 - I think it has to be the XT derailleur)  - e.g. 'goat link' and 'radcage', and buy cassettes (sunrace) or expansion cogs to take you 10X to 42 or 46 teeth. Ultimately is not what I would choose to do on a new bike as they are all various degrees of a hack with various degrees of success.

This leaves a chainring. This bike comes with 30 - you may be able to go down to 26 with direct mount cranks, but I looks like this comes with 104bcd meaning 30 is as small as you can go without a new crank set. You don't want to small unless you don't mind going slow, or know how to spin... 28/11 is a fairly low top gear.

Ultimately I suggest if you have any doubts that go to a 2x10 or a 1x11 (Shimano has recently announced a SLX 1x11).


It could be from a bad chain, bent chainring/sprocket, worn out cassette or freewheel, incorrect installation of chainring/bolts, bent tooth, missing spacer in the bottom bracket/cranks, bent crank arm, etc etc.
Have you inspected every single tooth on your sprocket to see if any of them are bent?  A bent tooth might cause a clicking sound.
Does your chain have even slack or does it fluctuate from more to less slack as you pedal?
If this is the case, you can fix the slack issue by tightening the chainring bolts in the correct way.
Is your chain clean and lubed?
A chain line issue could be causing the problem.  If any of the parts on your bike have ever been changed/upgraded, there's a good chance the size of the part was slightly off causing the chain to not be in perfect alignment.
Flip your bike upside down and look where the sprocket teeth are coming up through the chain. Are the teeth perfectly centered in the chain or does it favor one side of the gap?
If it's uneven, you can try using a bottom bracket spacer/washer to center the chain line.
Your bottom bracket/bearings might need to be checked out.  I once had a sealed bearing cartridge that was too old and used to make a popping/cracking sound every few pedal rotations.  Replacing it fixed the problem.
If it's none of these, try swapping out different parts and you'll locate the problem pretty fast.  Start with a part you were planning to upgrade or replace soon anyway or whatever's easiest/cheapest.


You can grease the bearings, but the grease won't last very long.  Better to just clean and oil them, using chain oil.  Do this when you clean & oil the chain.

If the derailer is really gunked up, here is what I do:

Lean the bike against a wall, with the derailer facing out.  Make sure you're on a surface that won't mind getting a little oil and dirt on it.
Place a section of newspaper against the wheel such that it covers the lower part of the wheel (trailing off onto the floor) and slides up behind the derailer.
Spray the derailer thoroughly with WD-40 or a similar spray solvent, to remove the gunk.  Ideally, use an old toothbrush to loosen hardened gunk.  (Yes, I know that WD-40 is not a "lubricant".  But it's a pretty good solvent/degreaser for this sort of application.)
Thoroughly wipe the derailer and surrounding area dry with reasonably clean rags or paper toweling.  Also wipe up the puddle that's no doubt collected on the floor.
Oil the derailer and chain with good quality chain oil.  For "general purpose" use (neither wet nor dusty) I prefer a "wax" based product such at Tech-Line KryTech.  Wipe away the excess oil.
Remove the newspaper and wipe again.  (Dispose of the materials "responsibly".)
Give the rim and tire face one more wipe with a clean rag -- you want to get as much oil off of these as possible (and even in the best of circumstances something will spatter there).


What is wrong with my bike? Where is this sound coming from?

If you have ruled out contact between the chain and the front derailleur, check the wear on the chainring. You may be getting 'chainsuck', where the chainring teeth hold on to the chain links as they try to peel off the bottom of the ring and carry them up until chain tension pulls them off. Often triple drivetrain bikes gets ridden in the middle ring more than the inner or outer so it makes sense this ring will wear faster than the others.

Inspect the chainring teeth, thin, pointy or sharkfin shaped teeth indicate advanced wear.

If your chainring is worn, you probably have a worn chain and cassette also. Check the cassette sprocket teeth for signs of wear also.

The best way to check a chain is with a wear gauge, these are not very expensive. If you have to replace the cassette and one or more rings you should replace the chain as well anyway.


Is a powered car tire inflator suitable for road bike tire inflation?

Buy a floor pump, also known as a track pump, instead of an automotive accessory.

A track pump will take about the same time to top up your tires as a small car compressor, and has an advantage of not needing electricity at all.

You still need the on-bike pump for punctures while riding, but in the garage at home a track pump works very well.  I ended up carrying a smaller track pump on my bike instead of a minipump.

Do get one with a gauge - doesn't matter if its analogue or digital but estimating tyre pressure by squeeze isn't ideal.  A track pump will last you decades, where the small tyre pumps tend to fail in a few years.

Incidentally - I've tried to use my big track pump to add some air to a car tyre, and after 10 minutes I'd raised it from 20 PSI to 22 PSI.   If you want to inflate car tyres as well, get both.  One pump will not do both jobs well.

My car tyre compressor stalls out at around 70 PSI  despite being "rated" for 175 PSI - there is no way it can pump up a road tyre and if I did, would have to finish it off with the hand pump anyway.


Bike with a hi-ten steel frame for getting around the city?

I have 4 bikes, and the one I keep for just riding around a city is high-ten steel. Yes, they're heavy, and normally cheap, but they can be tough and practical.

What's more important is that it works for you - that it's the right size and convenient.


Bike washed with pressure washer. How to recover?

You've basically got three sets of bearings on your bike: hubs, bottom bracket, and headset.  It's pretty easy to check if the grease has been blown out of any of them by listening to them spin or by checking for play in the part.  If anything sound gravelly when you spin it the bearing definitely needs some love.

The wiggle check is a little more drastic, but also worth trying.  If your dropouts are tight and you can still wiggle the wheel by grabbing the rim, you need to repack your hubs.  If you can wiggle one crank arm and the other wiggles, you need to repack your BB.

Play in the headset is probably the biggest risk, because a sloppy headset is one of the few maintenance issues that, left unchecked, can actually ruin a frame.  If there's slop in your headset and you ride the bike, the impact of the steer tube rocking back and forth can ovalize your head tube, and then you're kinda hosed.  So be really careful to check that your headset seems solid.  Turn the bars so the wheel is at 90 degrees to the frame and rock the bike forwards and backwards.  Put your fingers on the interface between the headset and the frame, headset and the fork crown, and headset and spacers, and feel for any play.  If it feels solid, you're good.


The Dinotte series of lights is great, and I love mine. I can get almost 2 hours out of my 200L on high mode. It meets all of your requirements, except for the one about bumpy/gravel roads -- if you mean by that something durable, then it meets all your requirements.

Dinotte 200L headlight and battery mounted on my helmet.


Yes, a hub that's loose and torn up inside can cause what you're experiencing, and given the evidence you present sounds pretty plausible.
Your experiences with the shops suggest that one or more of your bearing races (cups and/or cones, typically starting with a cone) are damaged. The one that recommended a wheel was cutting to the chase. The one that adjusted it did so because adjusting out the looseness of a damaged cup and cone hub can limp it along, but the nature of cup and cone hubs is that a good adjustment becomes impossible once there's any damage, and the damage perpetuates. So they tightened it, it got more torn up inside, and now it's worse - hence the virtue of cutting to the chase.
If it were just a problem with the cones, they can sometimes be replaced on an OEM wheel such as this. Having a shop do that plus the overhaul labor is often iffy value because the cups, which aren't replaceable, are likely to have picked up some damage at this point too. It's perfectly likely they're heavily damaged, in which case going straight to a new wheel is the only reasonable option.


Can anyone help me to identify my TREK mountain bike model from the serial number?

Pretty much all the yearly Trek catalogs and technical manuals for the 90s and 00s are found here:
http://www.vintage-trek.com/trek-fisher-klein-lemond.htm
There's also bikepedia.com and bicyclebluebook.com if you've got some idea of the model year and/or model number/name


What are these cracks in the side of my bicycle tyre called? Does this mean that my tyre is gone?

I'd say, it's time to replace the tire. It doesn't really matter what caused it - could have been low quality, age, or extended use. The cracks mean the layers the tire is made of are separating and in the long run you will see more punctures because the material is softening. A brand-name tire costs 15 to 25 EUR/USD/GBP which I consider low enough to not take the risk of punctures.


Website with bicycle only paths in Europe?

OpenStreetMap (a collaborative project to create a free editable map of the world) has a very up to date and accurate cycle route layer available. I have used it before in Europe to plan large trips.  There are also lots of online add-on services that allow you to use the cycling OpenStreetMap to plan cycling routes and run them either on smart phones or on GPS cycling computers. Garmin has even used the service to create the specialized maps on their Edge GPS cycling computers.

Some example services include:

BikeRouteToaster
Garmin Connect
... more to come (or add them in the comments)

As a side note, other proprietary services such as Google maps also have good (and constantly improving) cycling maps.  I however personally find OpenStreetMap is a little more up-to-date and accurate, likely due to the fact anyone can submit a fixes and new pathways.


Is it possible to fit a 36T chainring on a 34T frame?

I think you will have to go with Commencal's specified max chainring size.

Radius of chainrings at center of chain rollers is:

32t: 64.8mm

34t: 68.8mm

36t: 72.9mm

If tooth profile is the same, the tips of the teeth will be a constant height above the center of the rollers, so a 36t ring will be approximately 8mm greater in diameter than a 32t - as you calculated.

Doing a rough analysis on the photo you provided: the gap between 32t ring tooth tip and frame looks to be about the same as the depth of a tooth.

If we assume the tooth depth is the same as the chain roller diameter of 7.9mm, you only just have 8mm clearance. If the chainring does clear, any frame flex will likely result in the ring hitting the frame.


Innertube fat on one side, skinny on the other

You should mount the tire first and inflate second.

Tubes are not supposed to be inflated outside tires, they will behave like balloons but the material they are made of is not as stretchy.


Yes, your fork is disc compatible, but your hub is not. The fork appears to have mounting points for the older 51mm I.S. disk brake standard. See

https://www.bikeman.com/bicycle-repair-tech-info/bikeman-tech-info/1638-51mm-international-standard-74mm-post-mount

for examples of the two most common styles of disk brake mounts.


How to talk to authorities to convince them to bicycle initiatives?

Your best recourse is find yourselves rich and influential sponsors to advocate for you.

Or purchase the land outright.

Or a combination of both.


What is causing phantom shifting on front chainring?

One thing to check is whether the crank integrity is intact -- the shaft could be bent, there could be a cracked cup, or the axle/cartridge could simply be loose.  Also, the crank arm may be bent or loose.  If the crank shifts under load (due either to the axle shifting or a loose arm) it could easily account for your phantom shifts.

Next is the rings.  You imply that one ring has a "slight wobble", which may indicate a bent arm or may indicate the ring needs replacing.  Also, the rings may simply be worn to end of life -- from experience this can cause phantom shifting.

Another possibility is a "galloping" rear derailer.  If for some reason the rear derailer is not taking up chain smoothly it can cause front ring phantom shifts.


Does there exist optimal damping setting for all terrains?

Without digging too deep into the physics of damped motion now, I say "there isn't an optimal damping setting for all riders and terrains".

Let's consider first the critical damping case as defined in the wikipedia article. This is based on the case that you "excite" your system (i.e. set it into motion) once and then leave it alone until it has calmed down again due to damping. The best approximation in real life cycling would an isolated pothole or curb on an otherwise smooth road: once you've hit that obstacle, your suspension compresses and then returns back to its initial state, if there is no second bump during the time it takes the suspension to relax again. As the suspension is only uncompressing here, it's also only rebound damping that matters.

So what happens now as we go to a rougher surface where the time between bumps is shorter than the time constant of the damping, i.e. the time it takes the suspension to return into its initial state? Lets say the first bump you hit fully compresses the fork and as it has relaxed halfway back you hit another bump of the same strength which will set your fork again to full compression (if it could it would maybe even compress further). On the second bump your fork will only give you half of its travel as it is still halfway compressed from the first one. now consider an even rougher surface where the suspension can only uncompress 10% of its travel between bumps and you (hopefully) can easily see that sooner or later you will ride with your suspension nearly fully compressed, leaving you with no suspension at all.

To overcome this, you can reduce rebound damping which enables your suspension to uncompress faster at the cost of overshooting. Therefore your suspension gets more wobbly but it can react better to frequent bumps.

Compression damping comes into play when the suspension compresses (surprise?). A stronger compression damping reduces the speed the suspension compresses which is also the reason why most higher priced forks and shocks realize their lockout mechanism through high compression damping – this way you still have some suspension left for the really hard bumps. A stronger compression damping on your rough surface also means that your suspension is using less travel for the same sizes bumps, however, this time it is not converging towards the maximum compression level but tends to stay at sag level, i.e. the compression it has under rider weight. As a consequence, you can "save" a bit of travel for the really hard bumps if you raise your compression damping at the cost of a harder riding experience and a slower reaction of your suspension.


You can use a bike that's "too small" or "too big" without too many problems, so long as you set it up properly for your own biomechanics.

Try using this fit calculator instead: http://www.competitivecyclist.com/za/CCY?PAGE=FIT_CALCULATOR_INTRO

Compare the bike you really want with the results of the calculator. It will give three separate options, and provide you with a rough idea of whether the bike is likely to be a reasonable fit for you.

1.5" doesn't sound like a lot, but in the world of bike fit it can make a massive difference. Ideally you want to work around things that don't fit by changing components, but you need to know first if changing the components will help.


That's the thread pitch, i.e. the distance from the peak of one turn to the peak of the next. The best way to measure it without a gauge is to count 10 turns and measure how much length they take up, then divide by 10. For this sort of value you can measure the length of a single turn with callipers  but that's a less reliable method.

It looks like there are M12x1.0, 1.25, 1.5 and 1.75 through axles so you do need to be accurate. The way I've written it in the last sentence is the more common notation in engineering.

Metric threads have a pitch, which is a length, while imperial threads usually have the thread separation given in turns per inch (tpi). You may be more used to the latter.

Further reading:

http://bikeandskiblog.com/wp/2016/01/12/mtb-thru-axles-who-knew-there-were-so-many-standards/


removing broken mudguard/fender bolt from eyelet

You could try slicing, with a dremel or similar instrument, a 'notch' into the bolt that would allow a flat edge to fit in.
Soak the bolt/area with a penetrating lubricant (PB Blaster or some such) or ammonia, let it sit and do its work for a few minutes (some folks recommend 24 hrs), and then attempt to 'tighten it through' the eyelet.

You could also try to heat it w/ a propane torch for 30 seconds or so and then try again to tighten the bolt through eyelet.


Is it safe to go over roots at high speed on a cross-country bicyle?

It's safe as long as you use your body properly. Learn about:

proper neutral posture while descending:

light hands, heavy feet (stay above BB, mostly with your feet)
don't sit
knees bent
elbows out
back straight
look ahead (read the terrain), not on your front wheel, nor the obstacle itself for too much time

dealing with obstacles (roots, rocks etc):

choose a good line, since you are already looking ahead and not down
compress/weight before an obstacle
uncompress/unweight while hitting the obstacle

If you've never heard, thought or done any of the above before then give it a try. It'll improve your safety, confidence and handling on the bike. If you've been riding long enough not doing the above then it may be difficult to adjust. But it'll eventually happen. It needs practice and it'll not come overnight.

If you find this stuff interesting and you are really interested in improving your technique I suggest finding a skills lesson/course to take and also reading http://www.amazon.com/Mastering-Mountain-Bike-Skills-Edition-ebook/dp/B004D2BD1Q