It's hard to know exactly why that cap is so well stuck on, but you are right, it should pop of with a good firm tug. I believe there is a rubber O-ring that keeps it on. I have a DT-Swiss wheel that uses a similar cap, and when mine was stuck on like this,
soapy water helped me. I diluted some dish soap and poured a tad all around the cap and it popped right off. If you have an axle vise or a large drill chuck that might help you grab onto that thing to give it a good pull.


Guidance for buying large double saddle panniers

Unable to find anything suitable in my price range, and skeptical I would find anything tough enough outside of it, I spent a day sewing, and reinforced what I have.

I used nylon strap, 50mm x ~3m, and double folded nylon thread (so there were 4 threads per stitch) to replace the prior straps. I was able to loop the strap around a seam/strap/flashing which was just through the hole, you can see the threads looping over it. I attached the straps' ends taut to the bottom of each pannier.


Threading Shimano chain, over or under lug?

Shimano seems to keep a lot of their documentation online, you can find your specific manual there.

For example, the site gives this picture for DEORE XT RD-M8000 derailleur.

Essentially, the chain needs to follow the shortest path between the two jockey wheels.  When installed properly, the chain won't touch the plate at all.  If it does you've routed it incorrectly.  But it appears from your pictures that it's routed incorrectly, the chain appears to be held off of the upper (lower in the photo) jockey wheel more than I'd expect.


How should I mount a downtube shifter clamp that lacks a locating hole?

Above, so that the tension on the cables can't pull the clamp down.


How much pressure can mountain bike tires take?

Says on the sidewall of a tyre. Mine says between 40-60psi. They also have it in 'bars' if you like to measure in that.

Check out an example here
http://www.chainreactioncycles.com/schwalbe-magic-mary-evo-mtb-tyre-super-gravity/rp-prod118255

Says max 50psi.


Do aluminum rims provide better braking than steel ones when wet?

Since you have gone for steel rims and need to stop in the wet and are unlikely to upgrade to alloy rims straight away, I think you are deserved of a practical answer...

In the wet, with regular brake blocks, the alloy rim will have a better coefficient of friction than the steel rim. This much is known and these brake blocks are the wrong ones for your steel rims. You need the brake blocks designed for the job, the ones with a leather face:

Typically these are nice and cheap, they also last a very long time. In the wet they work remarkably well on steel rims, although it can take a wheel revolution for the braking power to kick in. To work around this 'turbo lag for braking' you can put the brakes on extra early to clean the rims of water and get into a habit of having your brakes ready on tricky descents, junctions etc.

You can run them just on the rear wheel first, in that way you can see how they work and use your existing rear pads on the front when the existing set run out.

Don't let their hum-drum appearance put you off - if you have steel rims they are a performance product.

If you want the in depth on 'coefficient of friction' as it applies to bike wheels and different materials, here you go:

http://books.google.co.uk/books?id=0JJo6DlF9iMC&lpg=PP1&pg=PA248#v=onepage&q&f=false


Specialized Rockhopper derailleur hanger needed.....which one?

I googled "specialized rockhopper derailleur hanger" and one of the links was

https://media.specialized.com/support/0000004464/0000004464_CG0421_hanger_fit_chart_rev2013.pdf

The Rockhopper table is on page 4 of 9 and looks like this

ROCKHOPPER
2011 2011 Rockhopper M4SL 26"/29er 9895-4021
2010 2010 Rockhopper SL            9895-4021
2011 2013 Rockhopper M4 26"        9895-4021
2006 2010 Rockhopper HT            9895-4021
2011 2011 Rockhopper Comp 29” HT LEFT  9898-4240    RIGHT 9898-4245
2010 2010 Rockhopper SL 29”        9895-4021
2008 2010 Rockhopper 29” HT LEFT   9898-4240
2008 2010 Rockhopper 29” HT RIGHT  9898-4245
2011 2013 Myka HT 29”              9895-4021
2008 2013 Myka HT 26"              9895-4021
2005 (Late) Rockhopper HT          9895-4021
2004 2005 Rockhopper HT            9894-4206
2003 2003 Rockhopper HT            989-4271
1996 2002 Rockhopper HT            989-4261
2003 2003 Rockhopper FSRxc         989-4271

So, with some exceptions, half of them use 9895-4021 which looks like this:

And is mostly in black with the odd silver one around.

The earlier models all use different hangers, so you'll need to remember when you got it, and work out its age from there.

Interestingly, wheel size seems to be unrelated.

EDIT OP says its a "specialized hanger 12" which seems to look like this:


Shimano 105 compatible 13- or 14- cassettes

Modern rear derailleurs do in fact have a min and max smallest sprocket specification as well as largest min and max largest sprocket specification. You can find the specs here.

The min and max size of the sprockets is not just affected by the chain slack the derailleur can take up, it's affected by the angle of the line the cage moves along relative to the center plane of the bike to maintain separation from the cassette. This is different for short and long cage versions of derailleurs - a long cage derailleur moves at a different angle than a short cage to track a wider range cassette.

The current RD-7000 SS (short cage) and GS (long cage) min and max sprocket specs are:

                 SS    GS
Low        Max   30T   34T
sprocket   Min   25T   30T
Top        Max   14T   12T
sprocket   Min   11T   11T

So if you have a short cage version you can use a 14 tooth smallest sprocket.


Compatibility of Tiagra 4700 shifter with MTB front derailleur

With doubles this sort of setup can usually be made to work reasonably well. There's at least one bike I know of on the market with the exact setup you describe, the 2019 Salsa Fargo Tiagra, and it does work. Putting a triple STI on a mountain front triple crank and derailleur is where it gets bad.


Shiny metal parts on a bike are either chromed steel, stainless steel, aluminum, or titanium.

Bare steel can be polished to a shine, but the shine will only last a few hours (if that).  Steel naturally reacts with oxygen in the air and turns to rust, so any steel that is not to be painted is generally plated with chromium.

Stainless steel (which is essentially steel mixed with chromium) can be polished to a shine and will hold the shine, but it's heavy and its properties as a metal are not ideal for major structural pieces (though it does make pretty good screws and the like).

Bare aluminum isn't really all that shiny, but rather has a matte finish due to being "anodized".  If aluminum is not anodized it also oxidizes and turns kind of a mottled white/gray.

Titanium can be polished to a shine and is reasonably corrosion resistant (it oxidizes but the oxide is protective).  It also costs an arm and is only found in expensive bikes.

You can attempt to polish the steel and then clear-coat it, but you're not likely to be very successful.  Steel that is to be exposed to reasonably harsh environmental conditions needs to be "primed" with a special type of paint that chemically bonds to the steel.  Other coatings are apt separate and peel off.


What bike crank do I have and how can I re-attach?

Based on the new photos, there's a nut missing.  Its been loose for a while, because the square taper hole is a bit wallowed-out.  That may have killed the crank arm, have to try refitting it to be sure.
You need a suitable nut that fits the threads on your bike's bottom bracket axle, if the old one is not trapped in the head of the crank.
I'd pop off the silver cap in the middle, lightly grease the taper, then refit the crank arm.  Then fit the nut and do it up tight with a socket - you can't use a spanner on this because its recessed.

I suspect this crank has been loose for a while.  You probably didn't cause this oritginally, but have exacerbated it by continuing to ride with the loose crank.
Tomorrow, retighten the nut again.  The crank will slide harder onto the taper over time.  Since its already damaged, you may as well try to save it.
If it breaks then you needed a new one anyway!
Check locally for a Bike Cooperative or similar - a left-hand crank arm, square taper shouldn't be uncommon.  It may be that you need a new bottom bracket axle too, depending if there's damage to the taper.

The reason yours has a (missing) nut and not a bolt is that its an older design, functionally the same.  A more recent cartridge BB would have tapped holes in the ends for bolts, the effective differences are a tiny bit of weight saved,  requires less space under the cap allowing for thinner cranks, and a smaller box volume.


Does the SM-BBR60 bottom bracket come in 68 and 70mm widths?

I did a web search with the model number, and the first hit is to Shimano product page that says that the bottom bracket comes in 68mm and 70mm widths. That, and the fact that your bottom bracket is marked as 70mm, suggests that the bottom bracket indeed comes in two sizes. If you are still unsure, you can use a ruler to measure the actual BB.

The 70mm model is useless to you. If it was sold to you as 68mm model, you should be able to return it. Even if you mistakenly bought the wrong model, you should still be able to replace it.


Safest way to carry luggage on my carbon frame?

The safest way to carry luggage on a carbon frame is to use a trailer, like the BOB trailers.

Carbon frames are very strong, but each area of the frame is designed and tested for the loads it expects from a given direction. Adding luggage to a frame not designed for it, i.e. Without braze-one or threaded mounts, is generally a bad idea.


Could I use the Ogio Mach 5 bag for cycling?

Trying to stick to objective points. When choosing a backpack for cycling you need to consider a couple of things beyond normal backpack considerations.

Fit - can the straps keep it stable as you pedal or will it flap
around
Weight - does it add too much?
Back ventilation - will you back get too sweaty
Aerodynamics can also be a consideration - shape, flappy straps etc.

Fit and aerodynamics are probably fine as this is meant for motorcycle use. You'll definitely want to check the weight. Back ventilation could be a problem as it obviously is meant to be worn over a heavy motorcycle jacket.


A quick detour into BING produces the manual from this link:
RD-M650
and partially shown below:

For your derailleur you're correct, 32T is the biggest cog you could have at the rear. It's possible a freewheel with a bigger cog (34T) would work, but you may have to block off that cog by adjusting the limit screws if the derailleur cannot handle it.

I don't recall these derailleurs being available in different cage lengths, they were long cage by default.


As I see it, from my experience you may have any one or a combination of the following issues (from most to least likely):

You keep on pedalling at force while shifting down. Usually, when you switch from the middle to the smallest ring on the front you are going uphill and you have to keep pedalling just to avoind falling over. Still, you have to significantly reduce the pressure you apply to your pedals while shifting. If this happens often you should try to change gears a bit earlier in the climb when you still have enough momentum to pedal without force for one or two strokes while your chain switches.
Your front derailer is not properly adjusted. Over time the adjustment of your derailer may shift a bit due to al the shaking, or due to dirt lodging between parts. It may need readjustment. If you don't know how to do this I would strongly suggest you ask your LBS for help about this.
Your rings are old and worn. Your rings have special grooves and notches on the sides. They are not there because they look good or save material or weight. They are there to help your chain catch onto the next ring. If the rings are very old these grooves and notches might be worn away too much. Ask your friendly local LBS what they think about your rings or just compare your rings to those on a newer bike.
Your front derailer is old and worn. Over time the different parts of your front derailer are subject to normal wear and tear and everything becomes more loose and you get some play. You can compensate for this a bit by readjusting your derailer, but eventually replacement is the only option.
Your chain is incompatible with your rings.  You say it looks compatible with the back cassette, but in the past someone might have changed the back cassette to a model that requires a very thin chain that is incompatible with your rings. Possibly to increase the number of cogs in the back cassette (and thus the gear range) without changing the rear wheel. Are back cassette and front rings the same brand? Can you find serial numbers? Can you find anything in the website of the manufacturer? Again, you might want to visit your LBS for help on this.
Your chain is old and worn. If you live in a very dry climate and are a master of bike maintenance this might be the problem. But usually a chain is rusty and squeeking years before it is worn too thin.


You want to try moving the derailleur by pushing it with you hand, which will isolate whether the mechanism is stuck, or if the grip part is stuck.  If you have exposed inner wires, then try pulling them with your hand to see if the derailleur mech moves.

Could be corroded wires in outer sheaths, damaged grip control, or corroded/frozen derailleur.

Note that twist shifts/grip shifts were pretty low on the quality scale, and tended to indicate a budget bike.  You might be on a hiding to nothing spending money on this bike.

Chain skip sounds like worn sprockets on the rear wheel, an elongated chain, and possibly impacted dirt between the sprockets stopping the chain sitting on the teeth properly.

Consider posting clear and well lit closeup photos of the parts, which may help others answer more accurately.


Still confused about clipless, walkable shoes and dual-purpose pedals

For many years, I used cheap Forte pedals (Performance Bicycle house brand) with a platform on one side and SPD on the other side. This was on a mountain bike. Shimano M-324 pedals look very similar ($45 at Amazon)  I used these pedals for years for all kinds of riding, including singletrack.  The dual-sided nature of the pedals made it a bit tricky to get started in difficult spots on the trail, but it would be very easy if you're riding on the road

I also have Shimano M038 shoes that have a recessed SPD cleat and are very good for walking around.  The cleat doesn't touch the ground.

These days I use a different bike with Shimano M-520 pedals, but I still use the M038 shoes for commuting occasionally.


Efficient bike parking/storage that younger kids can handle?

Depending on your garage arragement, I would consider sth like this, but for vertical position:

mixed with hoist:

with this kind of elevating mechanism:

If for horizontal, can be combined with this ( I suppose there is enoug space on the wall if you tried with hooks):


Loose brake cable hook bushing inside the brake/shifter hood

The little piece is the pivot bushing for the lever shaft. Its' job is to prevent a metal on metal contact point. You can reposition it by loosening the cable clamp at the brake caliper, gently slide the little barrel out far enough to install the bushing. By pulling the cable back every thing should go back in place.

It can be helpful to have a pair of needle nose pliers nearby, as you might need to pull the cable a bit to make the barrel move far enough. Also, if possible, move the shift/brake lever inwards towards the middle of the bike before closing the brakes to open up the hood as much as possible.


You can just buy a standard tapered headset. Or if you can firnt it, only the upper assembly for 1 1/8". Giant uses the same diamete for their 1 1/8" and 1 1/4" headsets as it says here: http://www.pinkbike.com/news/Giant-OverDrive-2-Steerer-tube-sizing-2011.html.

Another solution I can think of is to turn a spacer yourself (or have it done by someone) to work as an inner race for the bearing. It's more demanding (since you would have to turn both the spacer and a cap), but could probably work out a bit cheaper than the entire headset.


How do I correctly align the brake disc with the callipers when replacing my quick-release wheel?

Most modern disc brakes (mechanical or hydraulic) can be aligned by loosening the caliper from the frame or fork, grabbing the brake hard, and re-securing the bolts. Then once you let go of the brake, it should be centered.

Not ideal for the trail, but easy in the garage.


Spokes go further inside rim than others

On every single wheel I have built (and I have built 6 of them), the wheel looks mis-laced before the spokes have been tightened to the final tension, even though it was correctly laced. You tighten the spokes to the final tension and it starts to look like a real bicycle wheel.
One possibility is that you're seeing just this effect. Tighten the spokes more. If you cannot tighten the spokes enough, you have too long spokes.
Edit: on second thoughts, there is actually a possible issue you may have caused during the lacing. When lacing the first set of 9 spokes, it doesn't matter which hole you choose. When lacing the second set of 9 spokes, the first spoke must go to the correct hole. If you push a spoke through the test hole, you see that all holes in the left flange are inbetween the holes of the right flange. You need to select the correct hole: if the first spoke in the second set goes to the right side of the first spoke in the first set at the rim, the spoke hole at the hub needs to be just barely on the right side too. Not choosing this hole properly could perhaps lead to an issue where the spokes are regularly too tight, too loose.


What are the negative consequences of not bedding in disc brakes?

I think your last comment is the operative point - it will happen anyway sooner or later.

The technology here is basically the same as with automobiles. You start off with new pads and a clean rotor. The bedding in process involves the deposit a small layer of pad onto the rotor (mixed in with a little frictional heat).

Until you have that layer on the rotor, braking could be less powerful and uneven.

You don't ask this, but for completeness, the rotor should be cleaned whenever the pads are changed, using isopropyl alcohol. And, once the rotor is clean, the bedding-in process will start over.

You don't see an awful lot on this subject if you look on the web at bike pages, but as I say if you start looking in the context of cars, there's lots out there and it is definitely not new technology.


What variables best determine bicycle fit for an individual without riding it?

One thing that does make a major difference is the type of bike.  As a very general rule, the faster the bike is intended to be ridden, the more important the fit.  I'll address this from the point of view of what most beginners ride -- things like Euro-style city bikes, hybrids, and basic mountain bikes.

So most bikes that most beginners (based on your tags) would start riding on are quite forgiving. For a conventional geometry, leg length (i.e. seat tube length) is the biggest factor.  This is the key number in the frame size, and the frame is the most important thing to get right as there are no (cost-effective) adjustments or substitutions possible.  When cheap bikes are sized by a single number, it's usually based on this length, but comparison between makes isn't simply a matter of the length.  To some extent a too-small frame can be compensated for by raising the saddle, but it's much better to keep this for fine-tuning as too much seat post extension often results in the handlebars being too low. A frame that's too big can lead to disomfort or injury, even if you don't have to worry about a top tube.

The reach (approximately top tube+ stem length) and stack (handlebar height) are secondary.  They scale with the seat tube so should be about right for a typically-proportioned person. Both are also quite adjustable, though to get the most adjustment means swapping out parts.

The effect of this is that most people can buy a flat-bar bike based on top-tube height / frame size alone, and only worry about anything more than the most basic adjustments when they start considering longer rides.  Of course extra care is needed if you have back/leg etc. problems.


Should I sell a custom built mountain bike as a full bike or break it into parts?

It may depend on the overall age of the bike but I would guess that in most cases it's better to sell it as a whole. If the bike only consists of rather standard components that one could easily buy at a LBS, then they wouldn't make high prices and the additional work to break it all down and maybe set them all on on ebay separately may not be worth the money.

I can imagine only two cases where it may be better to sell it in parts or at least to sell some parts separately:

You have one or more high priced components on it that are still nearly new and unused, or
there are some (older) components that are no longer available from the manufacturers but make a high price even when bought second hand as they are required to repair an otherwise still working bike (imagine 7-speed shifters from the former higher priced component groups such as Shimano XT to replace a damaged one).


Shimano's most recent compatibility chart is available here. Note that these are official compatibility ratings. It is fine to exceed official specs by a bit.

At the rear, you can get a 10s Tiagra cassette that has a 34t cog, but it does technically require the long cage Tiagra RD. The issue was discussed here. The short cage Tiagra RD is rated for a maximum of a 28 tooth cog. If you have this, you could install a Wolf Tooth RoadLink to increase its maximum cog specification. You would need to be cautious not to exceed the rear derailleur capacity, or the maximum amount of chain that an RD can wrap.

You could also get an 11s GS RD, but be aware that they aren't officially compatible. In particular, if the 11s system is made with a different cable pull ratio (i.e. the length of shift cable pulled by each shift on the STI shifter), then an 11s RD won't shift correctly. You stated in comments that the cable pull ratio is the same, however.

At the front, you can't simply change the chainrings, and these are expensive in any case. Stock cranksets with Shimano's asymmetric 110mm bolt circle diameter can only handle a minimum of 34 or 33 tooth chainrings. Please don't construe any products mentioned below as recommendations; they are given as examples, and aren't an exhaustive list of options. You should Google to confirm.

Option 1: You could get a sub-compact crankset.

The Praxis Alba crankset can handle 48/32 chainrings. It doesn't appear to handle smaller ones. As stated in the dealer manual, this crankset maintains your 43.5mm chainline. However, this requires a new bottom bracket. For even smaller chainrings, you would definitely need a third party crankset, but many would also require you to change your bottom bracket. For example, the White Industries G30 crankset can accommodate an inner ring as small as 24t. This is a premium option. I'm uncertain about this crankset's chainline. Be aware that many sub-compact cranksets are designed for gravel bikes. Thus, most of them may have different chainlines.

The Shimano GRX cranksets are available in 48/32 or 46/30 ratios and they shouldn't require a new bottom bracket. However, they don't maintain your desired chainline. Nonetheless, I have heard anecdotal reports that people are running GRX cranksets with standard road front derailleurs.

Option 2: Get oval chainrings, such as the Absolute Black chainrings. They claim to have designed oval chainrings with average effective sizes of 48/32t and 46/30t that fit standard Shimano cranks.

The issue is that you may not like them, and they do need the front derailleur to be set up properly. I have heard some users comment that this was more difficult. Their purported advantage is that they decrease the length of the lever arm when your pedal stroke is in recovery phase, and lengthen it during the power phase of the stroke. These are claims only, and I don't believe studies have shown that they are generally effective.

The chainrings themselves are about as expensive as a new crankset, and they don't get you all the way to your desired gearing. However, you would be able to keep the rest of your current setup.

As discussed in the second link to a previous StackExchange post, you will need to be aware not to exceed your front derailleur capacity as well as the RD capacity.


Guessing from the picture, the make is "Viva" and the model is "Warp". It also looks like it's a relatively low/entry level bike, and may be relatively heavy for its size, and will be equipped with a lower quality range of components. It should be noted that there is a higher-end road/transit bike manufacturer that goes by the name Viva; this does not appear to come from the same manufacturer.

I could be completely wrong... It looks like there is a web address on the chainstay. Your best bet would be to contact the manufacturer with the serial number of the bike.


Purpose of fork with single bidon mount and no eyelets?

The mount is for pannier racks that sit low on your fork. In the absence of this mount I have seen a bracket used, but this is more secure. The rack also mounts using the front axle.


Can too many electolyte supplements be dangerous?

Yes, too many electrolytes can do all sorts of bad things to you.

Good article here: http://www.livestrong.com/article/521763-can-you-consume-too-much-electrolytes/

The U.S. Army has done a lot of research, here's probably the most pertinent paper: http://www.ncbi.nlm.nih.gov/pubmed/10410838

In general, if you are mixing the drinks according to the directions, you won't be too wrong. Most will be a more natural mix if you mix according to directions then dilute 1:1 with water.

Happy Riding.


£ so if you are in the UK, check out Edinburgh bike coop if there's one near you.

Definitely get disc brakes. Opinions on full suspension bikes differ - it used to be said that if your are spending less than $1000 don't get it. But I don't do extreme downhill so don't really know.

Most mountain bikers use camelbacks rather than water bottles because off road the bottles get covered in dirt (=cow shit) and you catch lurgy and die.  You can always add a water bottle holder later.


Saddle height for toddler's balance bike

They grow so fast it really doesn't matter, but if the kid looks too low then they are, so go up a bit.

Rider should be able to stand over the seat with both feet on the ground.

While some balance bikes have bike seats with clamps like this, they're in the minority for cost and weight reasons.

This wooden frame is far more common and much lighter for the child to manage.

Notice the seat-pole (plank?) only has two visible holes, for a total of only three seat positions.

Don't overthink this, just be an encouraging parent :)


Shimano Hollowtech II cranks use two pinch bolts to secure the crank to the axle. From your picture it looks like you have those. You are missing the plastic end cap, and you may possibly be missing a washer that sits between the crank and the frame. There is no spacer, the play is probably because the crank arm is not fully on the spindle.

To install the crank you just slide the crank on the axle (you may need to drive it home with a mallet), hand tighten the end cap to set bearing preload (this is important!) then do up the pinch bolts to proper torque with a torque wrench.

Park Tool has a great article and video that shows you how these cranks go together: https://www.parktool.com/blog/repair-help/crank-removal-and-installation-two-piece-compression-slotted

However, you may have a serious issue. The crank slides on to splines on the axle, and should not be able to rotate even if the pinch bolts are loose. If your crank arm became loose and rotated 180 degrees the steel axle has likely significantly damaged the internal splines of the alloy arm. If this happens the crank will not stay tight on the axle and will work its way off again.

Update following more info and pics from OP:

The crank splines don't look too badly damaged, so I'd give re-installation a try. If the crank comes loose again then you'll want to replace it.

I checked the RS400 crank manual and there does not seem to be a washer between the arm and BB bearing. You need an end-cap obviously. Googling for 'Shimano Hollowtech stop bolt' yields end caps for various crank models, but not RS400, I think a basic plastic one will fit. A bike shop can help you get the right part of course.

Installation is straightforward but there are a couple of things that must be done right.

Setting bearing pre-load with the end cap. A special tool is needed The Shimano part is TL-FC16, they only cost US$5.
The pinch bolts must be done up simultaneously and to the correct torque, for which you need torque wrench.

You can do the basic assembly and get a bike shop to check it and use a torque wrench to do up the bolts.

If you end up replacing the crank Shimano RS400 cranks are relatively inexpensive (I once bought an older used set for US$35 on Ebay). However, what I would do is upgrade to a proper Tiagra crank to match the rest of the drivetrain (RS400 being a slightly lower level, and cheaper 'non-series' item).


Often while mountain biking a twig or rock will get stuck between the swing arms on your front derailleur. This effectively locks the derailleur in place until the rock/twig works itself out.

If it happens again, stop and examine the derailleur. Generally you can't see the obstruction while you're riding.


GT Chuck 1.0 component transfer to full full suspension frame

Assuming that all of the receiving sizes are the same, then yes. Technically you can put parts sized for different wheel sizes on a frame meant for a specific wheel size (ala 69ers), but keep in mind that it will change the bike's handling and geometry.

Fork: If both are 1 1/8" or both tapered then you can. Keep in mind that the head tube of the new frame may be shorter or longer and affect how much steer tube sticks out. You could wind up without enough space to clamp the stem. Also, will you need to transfer headset cups and/or bearings?
Wheels: The front wheel can go if the fork fits, if not it just needs to fit the new fork. The rear wheel will need to have the same spacing and dropouts (135mm QR, thru-axle, 12x142mm, etc.).
Brakes: You might need an adapter to mount the brakes, but these are pretty universal and should work on any bike. Also check to make sure the hoses are long enough if the new frame is longer.
Drivetrain:

Cranks: Will work, but the bottom bracket must be of the same type (cups/pressfit) and size (68/73 or 83mm).
Shifters: are similar to brakes in that they're universal but the cables might be too short.
Front derailleur: Must be the same mounting type. The swing might be different, but it will work in some fashion, but maybe not the best.
Rear derailleur/cassette: The cassette is dependent on the wheel fitting obviously, but the rear mech should work fine.
Chain: I would say probably not, you'll have a slightly different chain size and it's a new bike, so might as well put on a new one. Plus, don't forget about the chain length change as the suspension moves through it's travel.

My recommendation is to compare the specs on both bikes and see how much is the same before deciding to swap all the components, as it will be a headache when you get halfway through the build and discover that you need to buy a different sized part! This is also a good time to upgrade components and evaluate wear.


What is a good daytime nutrition plan for evening racing

This is one of the most common questions from people new to racing. I notice user Rider_X has not responded (yet). If he does then it will be well worth reading.

This anwser is drawn from my experience with intense weekly endurance competition (squash), people who race bikes (father, brother, a dozen regular riding buddies, including several at the elite level, and an Iron Man competitor), my own experience preparing for intense non-race events, and the articles listed below.

Preparing for a weekly event the next evening starts 36 hours before, assuming you've done the training you need.

There are four things to do the day before.

Arrange to get a good night's sleep.
Eat a normal healthy balanced meal, including a moderate amount of carbohydrates.
Get your hydration level up to normal (since most people are under-hydrated).
Plan or organize your day tomorrow, so that you don't spend a lot of time

on your feet
in front of a screen
in high stress situations.

On the day of the race, eat your normal breakfast and lunch. Unless you usually skip breakfast, in which case make breakfast normal.

Two or three hours before the race, eat a light, low GI meal. One of the links below suggests

  Two hours before an evening ride, consume the equivalent of carbohydrates in grams as your body weight in pounds, for example 150 grams for a 150-pound cyclist. Keep protein amounts low, with virtually no fat ...

If you must eat later than that, then eat less and lighter, such as a banana. And keep well hydrated.

Sorry if it sounds disappointingly simple :-)

For more info, see these links

Cycling Tips What Should I Eat Before A Race?
Active Pre-Race Nutrition Guide for Cyclists and Fueling Up for the Ride
Bicycling The Best Pre-Race Foods
Bike Radar The best carbs for cycling - what to eat and when


Are there tugnuts made to fit forward facing horizontal dropouts?

I was able to use a surly tuggnut tensioner with my cross check frame with semi-horizontal, forward facing dropouts.  No slipping after that. The end of the tensioner bolt bolt nested in the opening on the rear of the dropout where the long wheel positioner bolt would be installed.  It would likely work on most bikes with this style of semi-horizontal dropout.

Looks like this:

The newer Surly Hurdy Gurdy chain tensioner is actually designed with the cross check dropout in mind (and should work with most semi horizontal dropouts). It's not going to get in the way of rack and fender mounts like the tuggnut. From surly's site:

  Hurdy Gurdy is another nifty device that keeps a rear wheel from slipping forward in the dropout under pedal load. It’s designed for our Cross-Check’s semi-horizontal front-loading dropouts, and will also work on many other similar dropouts.

Hurdy gurdy looks like this:


What to put after taking off rear stabilisers from child bicyle?

You want a washer and a nut on each side. Take it down to your local bike shop or hardware store to find the right size.  Any other parts that were on there were specifically on there for the stabilizers (training wheels).  Training wheels usually have a retaining mechanism that stops them from twisting, but this piece isn't needed once you remove the training wheels.


How to adjust Avid Elixir 1 hydraulic disc brakes?

The manual says they are self-adjusting but a shop told me you can adjust them slightly by loosening the rear caliper from the frame, squeezing the brake pedal gently, and tightening the caliper back down to the frame (to specs of course). Also, be sure not to loosen the screws holding the two sides of the caliper together, otherwise you'll let the fluid out and air in.


cable tension for Shimano 105 Front derailleur is very tight

First you should make sure your "high limit screw" is loose enough.  This may be marked H on the derailleur, or it may be one of two adjacent unmarked screws.  By loosening this you allow the derailleur to travel a bit more outboard.

Then, using some combination of adjusting the cable tension with the clamp bolt and with the barrel adjuster, set the tension so that the cage stays outboard enough (but not too much).  On your particular bike the barrel adjuster is inline with the shifter cable near the handlebars.

If your question is whether it's normal for there to be significant tension on the shift cable when the front derailleur is in the outer position, the answer is yes.  This tension must overcome the (fairly strong) return spring in the derailleur.


Is there a sign that a fork needs hydraulic/lubricating oil changed?

Over time forks become less responsive (move slower basically), but as this effect happens over the course of 12-18 months (the usual fork oil and seal lifetime), it's difficult to notice as you just get used to it.  So most fork manufacturers tell you to change it after so many miles.

This responsiveness loss happens for a couple of reasons on different types of damping systems, on mine (Boxxers) it's because of pollutants in the oil itself - 'dust' from the bushes, dirt, seal flake off, etc.

You can get a rough idea of the state of your fork oil just by looking at it, new stuff is clear tinted yellow.  I've seen fork oil come out looking like mercury from the sheer quantity of bushing dust in it...

Technically you only need to change seals once they start leaking oil, but of course that usually means that they've already failed their job - if you ride a lot in dirty conditions (which you should be!) they want changing every year.

Bushes only need changing once there's excessive play between your stanchions and sliders, this usually takes years but you can test the same way you would for testing a headset.


How do I tell what width chain my used chainring needs?

If it's 1/8" then a 3/32" chain will have to be jammed on to mesh, or not fit at all. The simple thing to do if possible is take a chain from a derailleur bike or even a scrap and physically try it.

1/8" chains and cogs/freewheels tend to go longer and on a singlespeed application, there is no downside (other than weight) to running them alongside a 3/32" ring, so you could also just get 1/8" for the rest of it regardless of what the ring is and call it good.


Should square taper cranks be greased before installation?

I started getting seriously into bike work circa 2002 and was lucky enough to come across Jobst Brandt's view of the topic around that time. Since then, most of which time I've spent working as a mechanic, I've observed that the Brandtian observations of the mechanical dynamics at hand are wholly correct, but I don't agree with him on what to do about it.
He posted a number of times on rec.bicycles.tech on this subject, material that can be found if you look, but there's an excerpt on sheldonbrown.com that I'll repost here:

My cranks get loose, quite quickly too; over about 10 miles or so from being solid to flopping about in the breeze. Any suggestions?
One or both of the cranks are ruined! Once ridden in the "floppy"
mode, the tapered square bore of the crank has been deformed and can
no longer be secured on a spindle. Install and properly tighten new
cranks on the spindle after greasing the tapered square ends of the
spindle. Proper tightness should be achieved with a torque wrench or
by a skilled hand.
The admonition not to grease the spindle finds life mainly in the
bicycle trade. When I discussed the "dry assembly" rule with crank
manufacturers, I discovered that they had warranty claims from
customers who split cranks. However, cranks cannot be split by
overtightening them. This can be proven by attempting to do so. An
M8x1 bolt is not strong enough to split a major-brand crank.
Failure from "over-tightening" is caused by repeated re-tightening of
properly installed cranks. In use, an aluminum crank squirms on its
taper, and because the retaining bolt prevents it from moving off the
taper, it elbows itself away from the bolt and up the taper ever so
slightly. The resulting loss of preload, after hard riding, can be
detected by how easily the bolt can be turned.
Loss of crank bolt preload is greater on left than right cranks,
because left cranks transmit torque and bending simultaneously while
right cranks transmit these forces separately. The left crank
transmits driving torque through the spindle to the right crank and
chainwheel while the right crank drives the chainwheel directly.
Besides that, the right crank transmits torque to the spindle only
when standing on both pedals. Doing this with the right foot forward
(goofy footed) is the only time the spindle transmits reverse torque.
Mechanics, unaware of why crank bolts lose preload (and commensurate
crank tightening), have re-tightened bolts until cranks split. No
warnings against re-tightening properly installed cranks are evident
although it is here where the warning should be directed rather than
at lubrication.

Because friction plays no role in torque transmission, preload in the
press fit must be great enough to prevent elastic separation between
the crank and spindle under torque and bending. This means that no gap
should open between crank and spindle facets under forceful pedaling.
Crank bore failure occurs when the press fit is loose enough that a
gap opens between spindle and crank. Torque is transmitted by both the
leading and the trailing half of each facet, contact pressure
increasing and decreasing respectively. In the event of lift-off, the
entire force bears only on the leading edge of facets and causes
plastic deformation, causing the bore to take on a "pincushion" shape
(loose crank syndrome). Subsequent tightening of the retaining screw
cannot correct this because neither the retaining bolt nor crank is
strong enough to re-establish the square bore.
The claim that a greased spindle will enlarge the bore of a crank and
ultimately reduce chainwheel clearance is also specious, because the
crank cannot operate in a plastic stress level that would soon split
the crank in use. However, increased engagement depth (hole
enlargement) may occur without lubricant, because installation
friction could ream the hole.
With or without lubricant, in use, cranks will make metal-to-metal
contact with the spindle, causing fretting erosion of the steel
spindle for all but the lightest riders. Lubricating the spindle for
assembly assures a predictable press fit for a given torque. Without
lubrication, the press is unknown, and galling (aluminum transfer to
the steel spindle) may occur during assembly. After substantial use,
spindle facets may show rouge and erosion from aluminum oxide from the
crank, showing that lubricant was displaced.
Crank "dust caps" have the additional duty to retain loose crank
bolts. Because crank bolts lose preload in use, they can become loose
enough to subsequently unscrew and fall out if there is no cap. If
this occurs, loss of the screw will not be noticed until the crank
comes off, after the screw is gone.

In other posts he put forward the theory that Campagnolo was the originator of the dry taper rule in cycling, because they were having issues with their cranks splitting at the taper bore with repeat tightening. Light vintage racing cranks such as old Record are in fact quite prone to this with lubricated spindles and repeat tightening. It is far harder to get such a failure out of any but the very fanciest contemporary square taper cranks. Most are pretty chunky.
In my experience, it is exactly right that square taper cranks squirm on the taper. It is also exactly right that if you grease the taper from the beginning, torque the crank bolts properly, and leave them alone, it will be fine. I've been doing this on my own bikes for about 17 years now with zero issues ever. I use 44 Nm as a generic square taper crank bolt value.
However, where the Brandtian line falls apart is that in practice, mechanics need to be able to rapidly torque check everything on a bike. We do it not necessarily because, as Brandt suggests, we don't understand that cranks squirm, but because poor initial assembly is rampant and we have to be able to correct it in an expedient fashion. That means crank bolts throughout their lives are going to have mechanics repeatedly putting a wrench on and tightening them until they hit full torque. A dry taper getting this treatment tends to reach a bottoming point where it's not going to squirm up the spindle any further, and where re-torquing the bolt won't drive it up the spindle any further either. If the interfaces were more commonly lubricated, splitting the taper would be a more widespread issue.
In some sense the ideal thing would be for mechanics to remove cranks all the time, grease the spindles to help ensure, as Brandt pointed out, the press fit is coming out as expected for a given torque input, and somehow compel the owner to make sure the crank bolts are never tightened again. In reality it's just not practical, and so we're left with the somewhat flawed de facto system of dry tapers as the norm. Brandt is correct that some galling of the mating surfaces can occur without lubrication, but it's rarely a meaningful problem.
Also, the nature of a press fit is that there's no room in there, so there's little if any difference in function between heavy and light lubrication. A thin coating leftover from the factory or applied as a rust inhibitor is pretty close functionally to slathering it with grease.


Brake oil came out of the piston of my Tektro hdc 300 and the brake is not functioning. What to do?

If you are going to do it yourself - you will need a hydraulic brake bleed kit.
You basically need to replenish the fluid in the hydraulic system.
This will either be mineral oil or Dot brake fluid.
Check with your brake manufacturer which it is.

There is a technique and procedure to bleeding brakes as well. Weigh up the cost of doing it yourself - or just paying an experienced cycle mechanic to do it. Its a fairly standard job and shouldn't take long at all - especially if it is only one brake.
Most hydraulic brakes are maintenance free - in that the system is sealed and air does not get into the system.

Unfortunately, you found to your cost - by removing the pads and pressing the levers - you popped the pistons out of their seating (and seals) which leaked all the fluid from the system. A tip would have been to wedge something between the pistons of the padless caliper - in case you accidentally knocked or pulled the brake lever.


What can be done wrong changing the chain in a single speed?

The photos show that the contact surfaces of the cogs have been worn to match the old chain. The new chain does not match them perfectly, which is the reason to the noise.

For some reason singlespeed seems to be much more sensitive than derailleur cogs. The good news is that if you can tolerate the noise and vibration for a while, the new chain and old cogs do wear to match each other. If you do not want to do this, replacing the freewheel should help.


Mounting Stiff Metal Fender with Strive Bolts

Bikes from certain times and places have used large (compared to today) unthreaded holes and draw bolts for fender attachment. Many old French bikes are like this. You've wound up with hardware for one.

You need the type of hardware used to connect the same struts to an M5 eyelet. They're sometime's called R-clips or -clamps. Here are the Velo Orange ones, probably around the cheapest out there.


How much can a 700x23 inner tube stretch?

Yes the tube size should match the tire size.   But a smaller tube will stretch.   Too big a tube may fold.

Max means max.  If the the tire says 85 psi max then that is the max.
If you weigh 180 then run the tire at or near the maximum.

Do not put 116 PSI in that tire.  Even if you have the wrong size tube pressure is still based on tire (not tube).


Is my Tiagra rear derailleur missing a screw?

I'm not sure if there are different Tiagra rear derailleurs, but if you look at the exploded view of the Tiagra RD-4700, I don't see any screws coming in from the underside (except for the bolt that clamps the cable), so I don't think you're missing anything.


Last year I bought a steel tourer.  It seems to tick all your boxes or near enough: £900, 27 speed, pretty rugged (timelapse of a ride I did last year, starting when I hit the gravel, before it got rough), and I can also do 300km days on road. I weigh less than you but then more than make up the difference on some trips.

A tourer's not your only option.  Cyclocross bikes and adventure road bikes (the 3 categories overlap anyway) will also do it but I wanted to be able to carry a lot, and you might do too.  You may want to swap tyres between rough gravelly stuff and serious distance. The combination of a heavy rider, potentially crashing through potholes (though I could be maligning you there) and a light road bike isn't a good one, which is a reason to go for a sturdier frame.

I'd steer clear of Halfords both because they don't have much range and because I've been unimpressed with their ability to sell bikes that actually fit the rider -- fit is important here as you want long rides, and drop bars make for a less forgiving fit IMO.

Mine came from Evans, but an independent local bike shop can often get similar pricing, and would have more chance of tweaking the spec if necessary.  When it comes to tyres, I suggest going for tough touring tyres, with a Kevlar belt. I run that sort of thing on my top 2 bikes by mileage, and I don't think I've had a puncture this year (over 8000km).

As you appear to be in the UK, do you have access to a bike-to-work scheme? Is that where your £1000 comes from?


mix left shifter and font derailleur of different speed

It will work OK while you should not mix 2 & 3 speed (MTB and road) front gears. 8 speed chain is a little wider than 9 speed and the FD will be a little wider but it's not much wider and will move your chain pretty nice. It's not affecting the shifter cable pull and FD move.
The problem in mixing 8 & 9 gears is in rear shifter.


I'm going to disagree with Frisbee and note that there are many cycling clubs which aren't race teams but are just a bunch of people riding together and supporting a community of cycling in the area.

There are several things that you can get:

Group ride organization (support for the rides, sometimes food, planning, etc.)
Discounts at local bike shops and for certain group rides which cost money
Access to a workspace (shared tools)
Meeting people who bike in your area (social networking too, like Strava groups or whatever)
Advocacy for local cycling efforts (trails, etc.)
In some cases, the clubs run race teams as well (which will increase costs, to get team kit and stuff).
Insurance (as pointed out by RiderX in the comments)

That being said, is it worth it? Look at the clubs in your area and look at how much they're charging. If it makes sense to you, you may want to go for it. If not, don't. A lot of clubs are only 15-20 dollars a year, some will be good, some will be bad. Some will be more expensive, and some will be free, depending on how much they're providing and what not.

The best thing to figure out to avoid or join a club is to talk to cyclists in your area -- you may want to visit bike shops you trust and talk to the staff there, and other cyclists you know in the area. If you're new in the area, you may have some work to do in this regard.


Is movement in my bottom bracket an issue which requires attention immediately?

I'd suggest you try tightening the Non Drive Side cup and see if there are any improvements.

You don't even need to remove the crank for this.  The right tool will just slip on, or you can get away with a big spanner and some plumber's sliding jaw grips.

If this helps the problem even a little, a proper clean and regrease will help a lot more.

The risk in not doing this is that there will be damage done to the cones in your BB, and if metal flakes off the inside surfaces where the bearings run, then its toast and you will need a replacement.  A cartridge bearing is relatively cheap these days, and is well worth doing even on a beater bike.


If you are only replacing the 4 broken spokes then you will need to duplicate the wheel's spoke pattern.

If you are re-lacing the wheel with new spokes, a 3-cross spoke pattern is time proven pattern that is great for a first time wheel build. It is easy to implement, it builds a very strong wheel and it makes re-truing the wheel a straightforward.  All of these are great features for your first wheel build.

After building, ride it a bit, and see how you did before trying to chase more exotic spoke patterns.

My reading of Sheldon's  POWerwheel page is that the pattern is a bit of a joke, but may actually work.  Even if it does work, it wouldn't be a good first time build as tension the wheel would be more difficult than a standard symmetrical pattern such as a 3-cross.

——

Update: check Jeffery Bell’s answer this was an April fools day joke (it’s a bit hard to spot now with all the ads, but at the bottom it is dated for April 1. Crazy that some have apparently tried the pattern  in real life.

Please give Jeffery an upvote.


Why are bearing ball sizes measured in imperial units?

My father worked at Fafnir Bearings for 35 years and even though it ceased to exist as an independent company about 50 years ago,  the trademark is still active.  In the post World War 2 era, Japan rebuilt its bearing industry using Imperial standards.  Bearings are a strategic technology in a manufacturing society and any rational government will promote policies that protects and promotes important  sectors.  At the end of WW 2, the US bearing industry had the right processes to make the best bearings.  They had the “recipe”.  Bearing plants in Japan and Germany were prime bombing targets and their assets, including people were very much destroyed. This made US and to some extent English bearings the target to reverse engineer after the war. If you need to figure out someones recipe, you should stick to making the same thing.  Annealing times and temperatures are dependent on the dimensions of steel.  Automotive and bike bearings were nearly optimal at a low price point, in the 1950’s .  The machines and tooling were well established, and an export driven economy would want to produce standard products.

I think it simply is a matter that making these sorts of bearings didn’t merit the resources to shift to a different standard.

Another factor is that as America has deindustrialized, the machines and tooling were sold off to Asian  countries.


There is a Wiki with an International List of Bike Collectives and Community Orgainizations at BikeCollectives.org.

There are many other organizations, like the Salvation Army in the US, that take almost any item and either operate second-hand stores or sell the items to other thrift shops.  I prefer to deal with organizations like the Salt Lake City Bike Collective because I know the bike is going to checked well and repaired if needed before being returned to the community.


You need to measure the grip area diameter (the diameter of the handle bars where the brake levers clamp onto). I'd suggest using a pair of calipers.

22.2 mm will fit flat bar (typically mountain bike/flat bar road) components, 23.8 mm will fit drop bar (typically road) components.

Note that you need to also get compatible pull brake levers -- in your case, you have a caliper brake so you need a short pull brake lever (ie. one that is marked for not linear pull/V-brakes).


is it compatible the left crank arm of ultegra 6600 with ultegra 6800?

Both the 6600 series and the 6800 series use the same diameter spindle(24mm). The interface is Shimano standard Hollowtech II.


What is safer...coaster brakes, rim brakes, or fixed gear braking?

A track bike (fixed gear) has no front or rear brakes.  You slow the bike down by resisting the turn of the pedals but you need to be careful to not push too hard, which can lock up the rear wheel and cause a skid.

But most fixed gears aren't true track bikes.  You should be able to find one that has standard brakes on both the front and rear wheels.  The front brake is especially important since that's where most of your braking power comes from on a normal bike.

A coaster brake is basically a drum brake in the rear hub.  Pedalling backwards engages the brake.

Personally I would expect a bike with a normal front rim or disc brake to be "safest".  Front brakes have much more stopping power because your weight shifts to the front wheel when slowing down.  Plus you can control the amount of braking power more easily by hand than by resisting with your feet.


How do I remove the wheels from my bike (not a typical nut)?

That's a pinhead security fastener. You should have got a key to match with the bike. Without the matching key number you can't get a replacement key either.

Here's a picture of a pinhead key fom about 2010. Yours will look at bit different. The key number is under the red blob, and the pins to mate with the nut are in the silver bit on the right.  As you can see, mine is old and battered, so the original keyring attachment failed and I drilled a hole in it.

There's another format that looks like a hex nut on one end as well.


Is this damaged aluminium frame unsafe to use?

If that's a chainstay/seatstay, then it really is unsafe.

With regards to @DavidRicherby and @ChrisH 's comments, I agree that you should go consult your LBS or any local frame builder. If you're lucky enough, it might just be salvaged by bridging/filling that hole by welding.

If you do plan to ride it in rough areas then I personally suggest you get a new bike frame instead. Fixed or not, the chain/seatstay is already probably compromised enough that I'd get off and lift that bike up every time I encounter a pothole or speed bump.


I can not give any advice, but I can present my personal story and experience. When I was a child, I was diagnosed with asthma. I needed to take a lot of medications in order to fight against asthma. I stayed also a lot of nights in hospital. At the age of 11, doctors suggested my to try endurance sports. I have chosen cycling. In fact, I really had a lot of problems with breathing in my first two years of cycling career. I needed to take Ventolin (Salbutamol) every training. During the years, situation became much better. After some years of training, I became competitive enough on a national level. In line with this, I have never faced any major problems with asthma again. I am racing now Ironman triathlons without any medications. I only sometimes have problems with breathing when there is a mix of hot and cold weather. Usually, when Autumn is transitioning in Winter I need to take one or two inhalations of Ventolin. Anyway, I also avoid riding in fog.


If that's a Cannondale, it is a Chase, probably a Chase "2".

http://www.bikepedia.com/Search.aspx?Q=cannondale%20chase


Long term benefits and risks of bicycling

Long term benefits ... Hmmm ... does 55 years count as long term? If so, I think I and a few others here qualify ...

Key benefits

Cycling is a life-long form of exercise. One of the group I meet for coffee is 82, another is 80. A bunch are in their sixties and seventies, and another bunch are in their fifties. About a quarter are women. Another bunch I ride with has people from late teens through to sixties. Half are women.
Cycling can be done in a thousand ways. I've seen young professional Italian women cycling to work in high heels, Italian grandma's cycling to meet for coffee, and their menfolk kitted out in lycra for their daily "roll". You can race, tour, commute, shop, goof off, cycle around the world. It can be your only form of transport. You get places faster than walking or running, and see almost as much.
Cycling is low impact (unless you crash). If you choose to cycle with intensity, it is has far lower impact on your joints than activities such as running, jogging, the latest Gym fad, and even swimming (which can be damaging to elbows and shoulders).
Cardiovascular, aerobic capacity, strength, metabolic level. Most of the health issues of today's world are due to too little of these. You are going to be healthier, and healthier for longer, with a cycling life style.
Endorphins (feel good hormones) are released by cycling. You cannot stay grumpy or depressed with a cycling life style.
Office productivity. If you're a sedentary office worker, the higher metabolic rate and higher blood flow will give you more energy at work and higher productivity.
Weight and cholesterol control. The higher metabolic rate produced by regular physical activity enables your body to burn it's way through lots of fats and foods.
Social. Meet a significant other. Whatever.
Bedroom performance. For either sex, bedroom performance is better when you're fitter.
Being quicker than cars through inner city traffic.
Being able to bypass traffic jams.
Idealists may think they'll save money.

Key risks

Crashing, or being crashed. On a bike you are more vulnerable. The solution is to simply take 100% responsibility. See Best ways to avoid getting hit by cars?
There have been medical reports of lower sperm counts among (male) cyclists. This one has always been exaggerated. Your better general health is a far better indicator of reproductive success.
Owning too many bikes, each of which costs more than your car.
Er ... hard to find too many more. Too much vitamin A? Being annoyingly happy with life? Annoying your friends by knowing what a kilometer is?


Using the outer lane of an inner-city one way system - where do I ride?

The way you're inclined to do it is the right way, but you're kind of stuck if your buddies aren't as comfortable in traffic, and you want to stick with them.  I rarely face this specific situation, but I've many times run into something similar when making a left turn across multiple lanes -- I just get into the turn lane and make my turn, but other riders are reluctant to leave the right shoulder.

(Of course, in part your situation is a comment on the bicycle-unfriendliness of many urban road designs.  Designers (who obviously don't ride bikes) think the mere existence of a bike lane is "bike friendly", when that's really the least of the issues.)

[I'd add that there's absolutely nothing wrong with being a bit slower than other traffic and occupying a lane for a relatively brief period.  Few people would get upset if a truck did it.]


To a large extent a magnet is a magnet (so long as it's strong enough).  You may have to mount it in the correct orientation.  A spoke-mounted magnet is quite easy to make or cheap to buy. The one that mounts on the crank for the cadence sensor may be a little harder, but I've got one that just relies on fixing to the pedal axle with its own magnetism (from a sensor that's too cheap to actually work reliably). You might not need a bike shop in that case.


How could I find out about my bicycle brand/model?

I share your doubt that it's a genuine Colnago.

I Googled "when was colnago clover leaf embossed" (you could try that with the .au removed also).

The hits show plenty of people asking such questions, and a couple of the hits seem to provide valuable answers

Unraveling the Mystery of the Colnago "Clubs"
How to identify a fake or genuine Colnago

Both of these suggest that without the "Club" embossing, it's not the genuine article.


It's the carbon weave visible through the matt lacquer. it's an attractive finish but not everyone loves it.
That is a UD weave rather than the easier-to-identify 3k, which looks like fabric.


How fast do you need to be going to get an effective slipstream on a bike?

It depends.  I don't know of any scientific research to support an actual speed.
The main factors are the speed of the wind that you are riding in, and the size of your shield (i.e. the bunny in front who is giving you the wind break - the bigger the better) and how closely you follow.  In still conditions I find that even at about 24km/hr (15mph) I will notice after half an hour or so that I have not worked as hard had I been riding out the front.
If there is a raging head wind then virtually any speed will find you having a noticeable advantage in the slipstream.  Just try being out for a while at the same speed and you will feel the difference in your heart rate and muscle output.
The size of your shield also helps.  Being in a large bunch effectively increases the size of the shield, though it is not a linear increase, but rather a diminishing one. That is, as you go from say two riders to 5 riders you get a fair increase in advantage , but going to 10 riders only gives you a small increase in advantage over 5 riders.  The third factor of distance is not as important I feel, provider you are within one to two feet and are not going at top racing speeds. As you go faster the distance at which you get an advantage increases.  Of course the maximum advantage is obtained when you are within millimetres of the wheel in front, which is why track racers ride so close, but then you increase you risk to touching wheels and having a crash.


Probably the simplest is to replace the hubs with internally geared hubs.  There are many of those on the market with a wide range of gear capabilities.  You may find it easier to buy complete new wheels.  You need to check all the interfaces of the wheels-the width and diameter of the axle, how it mounts to the frame, the width of the rims if you are using rim brakes, the width and height of the tire fitting in the frame.  You need to add a control for the gears and cable back to the hub to carry the information.  Presumably your dropouts are horizontal so you can set the chain tension properly.  This will be maintained with internally geared hubs.  You might need to change the size of the front or rear gears depending on the gear range you desire and the hub you select.  That will impact the length of the chain, which is easy to adjust.  I would go into one (or a few) local shops with your question and see what they suggest.  It would be good to determine where your problem lies.  Do you want a lower gear for climbing hills?  Are you close, but just need one a little lower?  Are there some hills that are far too hard?  Do you need a higher gear because you can't pedal fast enough?  Again, are you close or far from what you want?  These will help the shop with recommending the proper solution.


Road bike getting punctured often on poor roads

Kevlar tyres.  Or at least kevlar liners.  Check the pressure regularly, especially if running on patched tubes.

I suspect sharp debris/litter may be the problem

Lining with old tubes doesn't seem like a good idea - they're no stronger than the tube you've got, and add significant bulk affecting how the tube sits.

For properly bad roads, I wouldn't ride on road tyres - get something designed for rougher urban use.  All the major tyre manufacturers make something with kevlar, slightly thicker rubber and a bit of grip compared to road tyres.  I've fitted continental's version to a mountain bike for city use, and it will take much more sharp stuff than MTB tyres.


How does one extrapolate riding calories to fellow riders?

No, calorie burn does not scale linearly and can vary based on a great many factors.
Calorie consumption is very closely tied to power output.  Power in watts x4 is usually considered a good estimate.
If the entire ride was on a steep climb using tyres with virtually no rolling resistance, then in this case you would be correct.  However on a real ride other factors come into play (rolling resistance and aerodynamic drag).
In terms of rolling resistance, there is a large variance between tyres - or even between the same tyres at a different pressure.  This will also change (but not linearly) with rider weight.
Increases in body mass also do not lead to a linear increase in aerodynamic drag.  Further to this, power output can change a lot due to a riders position and clothing.


Getting local businesses to install bicycle parking

I wanted to update contributors and thank you for the input.
The biggest grocer stores, namely Publix and Kroger has Media Relations staff that gobbled up the idea.
 Bike parking is low investment and has a big payback in PR!
It helped ripping this image from the latest NACTO Bicycle Design Guide and emailing it with my communications (email, phone call followed with a letter) and copying my councilwoman for endorsement.


Is shift cable protector under bottom bracket on cyclocross bike important?

The thinking with them is to protect the contact point from contamination and provide a slick surface, reducing friction. They do achieve that to an extent, especially early in their life.

The problem is when the liner itself starts junking up with grime that can't be easily removed, it will then cause friction problems itself. For this reason, I think going without is fine in many cases.

Some bikes use them to prevent cables from rubbing the frame on painted surfaces, raw carbon, etc. In that case I would not recommend going without.

You can get replacement pieces from inside shift housing. Take a long piece, cut the outer plastic down it longitudinally with a razor, then whip it hard against a hard surface. The wire strands will come apart and you can take the liner out.


Different tone of lens in glasses for bicycle

It probably just means that the quality standards aren't too exacting. Kind of like how display panels with a few dead pixels aren't considered defective.

You could contact the manufacturer to ask whether the problem is covered by warranty, or you could just return them and buy a different brand. There's no point in keeping glasses you dislike.


Uncomfortable rise and backsweep on wide mountain bike handlebars

That "rise and backsweep" makes it easier to handle the bike when standing up. You'll notice that this is more pronounced on downhill bikes.

I am also uncomfortable on a flat bar, and I use bar-end bullhorns (I don't know if you could install these on a carbon bar).


What kind of spokes for Giant PSL0 wheelset

Are you building this wheel yourself? There's a bit of planning that goes into building a wheel. As Daniel mentioned, length and gauge are important, but even before that you must have a hub that will accommodate the same number of spokes that the wheel will. Afterward, the number of spokes you will need will dictate what lacing pattern you should use.

As always, Sheldon has the answers.


how to remove broken grommet from recumbent seat (without damaging mesh)?

After looking at half dozen videos the easiest means seems to be a Dremel or highspeed die grinder. Using a small diameter stone or steel burr make repeated passes around the inside of the grommet hole. Take care to not let the grommet to get hot enough to melt or burn the fabric. It is not necessary to grind all the way through, just remove enough material weaken the crimp.


Shock bolt size and threading can vary a fair bit. At least they also tend to be easy to find. I believe that takes an M6 x 1.0mm bolt. Probably about a centimeter long. If a 5mm allen wrench is the right size, I'm probably right. It could also be an M8 x 1.25mm, or even M8 x 1.00mm. All of these can be found in any bicycle shop and most hardware stores. I'd recommend dealing with it in person though because online shopping / shipping is slow and you'll get very frustrated if you get it wrong.


You're still young - at 15 you are still growing, so work on endurance and technique, and not too much on raw power.
And remember its not about ultimate top speed, there's got to be an element of enjoyment too.  So work on enjoying your time on the bike, but also have a life off the bike.


Will putting an e-bike chain on a "traditional" road bike give more mileage?

Chains don't stretch under any kind of normal use, even the kind of power that an e-bike can put out (which, to be fair, can be several multiples of what a fairly strong rider can put out for extended periods).

Chains elongate through wear: the combination of lube and environmental grit acts as a grinding paste between the moving parts of the chain, so that side-plate openings enlarge (or rivets wear down), resulting in a longer chain overall.

If you want your chain to last longer, keep it clean.


Presumably what is happening is that the stem bolts are not providing enough clamping force of the stem onto the steerer, and the stem is moving off center. You can check the alignment of the stem and wheel by looking down on then from above. The stem being mis-aligned should be obvious.
There are no 'internal bolts' in the headset, so you may mean either the steerer tube expansion plug or one of the stem bolts. If one of the stem bolts was stripped the thread in the stem may also be damaged.
Try making sure the bolts are tightened to correct torque (should be printed on the stem). If a bolt will not tighten to that torque the stem thread is damaged and you need to replace the stem. You can also try a carbon installation compound that helps grip carbon components.


Updating my vintage Shimano 600 chain rings

There are a couple different approaches. You can select basic, traditional-style chainrings similar to what came on it that don't have any shift-assisting ramps or pins, or you can put fancier indexed-shifting-friendly rings on it.

Traditional plain rings are often sold under house-brand type names such as Vuelta, Origin8, Dimension, etc. They're often fairly cheap, although fancier ones in this camp do exist, i.e. the laser-cut-in-the-US Salsa ones that were around for many years, or something like T.A. rings.

These sorts of rings are more or less designed to replace stock ones on older cranks such as Shimano 600s. They'll probably just work with a 7-speed chain with no issues and no need to mess with anything.

If you wanted to get ramped and pinned rings, which are more designed with 9/10/11-speed era chains in mind, you may run into issues with them being intended for narrower spacing, which may cause issues such as the chain wanting to rub on the large chainring when in many small ring combinations. Chain compatibility issues in this direction can almost always be solved by tuning the spacing with chainring shim spacers, such as the .6mm Wheels Mfg ones or a small stack of the .2mm FSA ones. And on that note, you may find you need them on the other setup too; chainring spacers are always handy to have when replacing chainrings. They're kind of the way to make things work when the "right" chainrings are no longer available or whenever you're using a chain type that's wider (aka older) than the one intended for the cranks or the rings.


How to correctly identify bearing cones for axles, to find replacements?

I find it rather difficult to get cones by themselves in Germany. It is much easier to get an entire replacement axle with cones. Often enough I found the whole assembly to cost less than an individual identical cone.
The good thing about cup-and-cone hub bearings is that there are only two ball sizes. The front always has 4,762 mm (3/16 inch) balls. That means also the races on the cones will fit.
When the outer diametre fits as well and the cones have about the same length a different axle with their cones might do.


What bicycle safe anti-car road spikes exist?

Keeping cars off a bike path is easily done with bollards. Good solid posts 1-1.5m apart will completely block cars, and the middle one can be a removable, lockable version to allow service vehicle access. Alternatively a gate can be provided next to the bike gap. This also permits horse riders. Where the primary concern is horse riders but bikes are permitted, a gate that a horse can step over is sometimes fitted. A cyclist has to dismount and lift the bike over - one thing on a lightly loaded MTB, another touring with a trailer. Here a picture of one (CC-by-SA David Hawgood via Geograph.org.uk):

In this case it would also be possible to get a bike round the gate.

Some care is needed in designing the layout of bollards and similar to ensure that recumbents and especially trikes can pass, but a straight stretch of path makes this easier.

I suggest that blocking cars isn't the hard part. Blocking motorbikes is the hard part and not one I've seen a good solution to, as off-road motorbikes aren't much bigger than bikes (narrower than trikes) and can be lifted over a step-over gate.


A big part of your problem is purely what you are used to and comfortable with, however wide, flat handle bars are used on comfort bikes and mountain bikes as they tend to offer more stability (at least, more perception of stability) than drops. I never feel as stable on my roadie on drops as I do on my MTB with relatively wide flats - although on the roadie I never screamed down bumpy technical single track at insane speed, so do not consider the relative instability of drops. However, hard to know if this is purely down to the bars, or the different the riding position, bike geometry etc.


As other have commented it appears to be based a legal opinion. While there is no physical reason they would not work the safety side says having sharp pins sticking out would not be a good idea. The potential for someone to strike a shin against the pedal warrants the warning.


Why use multiple materials on chainrings?

This is actually a matter of the force multiplication that each chainring provides, and the size/mass of each chainring.

Force difference

Let's propose, only for a moment that you had a chainring as big that the radius of it is almost the same as the crank length. If the rider stood to pedal while using that chainring (and using simple platform pedals). The max theoretical force on the chain will be equal the the rider's weight. (Assuming he/she is not pulling on the handlebar).

Now, let's get rid of that impractical and ridiculously large chainring, and install a more realistic one, one that has a radius of approximately half the length of the crank. Now when the rider repeats the previous experiment, now, the maximum theoretical force applied the the rider's weight*2.

If you repeat the whole experiment, but this time with a chainring having a radius of 1/4 of the crank length, the maximum force in the chain would be 4 times rider's weight.

That is, In a simple mechanism like a crankset, the output force can be calculated as:

OF = IF * (Ir / Or).

Where IF = Input force, Ir = input radius, Or = Output radius. And radius is the distance from the axle to the point where the force is exerted.

As you can imagine, most tripe chainring crankset have a large chainring that has a radius roughly half crank length. An the smaller chainring is half as big. Effectively, the typical triple crankset doubles the output force in the small chainring relative to the largest.

Weight matters

However, this is only part of the topic. The bigger the chainring, the heavier it is. And it is also a rotating part of the bike, so, some may argue that it's rotational inertia would matter. As you can guess, CroMo chainring are heavier than Al.

Durability

That still doesn't fully explain the decision, but here it goes: aluminum typically has less resistance against friction wear than steel. For example, if you had to file down a bump in an aluminium piece, you would do it with low effort, compared to the similar job on even mild steel. Added to this is the fact that a new chain in a new chainring engages several teeth with full roller-tooth contact, effectively spreading the load among each contact point. The small chainring can provide less contact points to spread the load, with means that each tooth is subjected to a bigger fraction of the total force applied by the rider and multiplied by the crank. That means that a tooth in the small chainring bears a much greater load than a tooth in the big chainring.

Usage ratio

Into this we can add the rather subjective argument that most riders would spend more time in the middle chainring, perhaps in the small one or jumping a lot between them, while the large one is used more sporadically, usually in fast descents where the rider won't use his/her full strength and not for long.

Conclusion

All of these arguments make the chosen materials good compromise between weight, durability and maybe, cost.

Aluminum small and middle chainrings would wear out too fast, and would be prone to bending from incorrect shifting technique. A big chainring made of steel would be heavier and the difference would be easily perceptible while holding the crankset in hand, so the crankset with the aluminum big chainring would make the best buy among the two.

The weight difference between small chainrings made of these materials would be less perceptible, and the buyer may not be so appealed to pay the price difference for such a small weight loss(gain?).

Also, aluminium small chainrings may be better suited for professional riders, whose may ideally be properly sponsored, so spending a chainring per race is not a big deal. Also, he/she may (ideally) have an optimized shifting technique (i.e. the rider has identified his/her shifting technique faults and has corrected them).


Rear derailleur and front shifter are not indexing "together"?

If you need to replace the cable, try this:

Shimano 105 Shifter Cable Removal

Take the bike for a short ride and shift into the gear that gives the shifter cable maximum slack. For the front gear shifter, maximum cable slack corresponds with the lowest gear. For the rear gear shifter, maximum cable slack equals the largest gear.
Loosen the bolt on the derailleur that secures the shifter cable with a 5-mm hex wrench. The shifter cable is attached at one end to the Shimano 105 shifter and at the other end to the derailleur.
Cut the metal cap, called the "ferrule," away from the end of the cable, using cable cutters. Grab the cable where it enters the derailleur and pull it free.
Squeeze the shift lever on the Shimano 105 gear shifter to expose the head of the cable. The cable head is located on the side of the top of the shift lever.
Grab a portion of the cable and push it forward, forcing the head of the cable out of the Shimano 105 gear shifter. Grab the head of the cable and pull the cable free.

Shimano 105 Shifter Cable Installation

Thread the replacement shifter cable through the hole in the Shimano
105 gear shifter. This is the same hole from which the old cable
emerged. The cable has two ends, with a metal fitting at one end,
which is designed to anchor the cable inside the shifter.
Pull the shifter cable taught until the metal fitting is fully
anchored.
Pass the cable along the bicycle. The cable follows the exact route
of the old shifter cable, passing through the cable housing and
cable stops before arriving at the derailleur.
Thread the shifter cable beneath the derailleur bolt and pull the
cable tight.
Tighten the derailleur bolt onto the cable, using the 5-mm hex
wrench. The cable will be excessively long and will need to be cut.
Cut the cable just past the derailleur bolt, using the cable
cutters. Leave enough cable, approximately 2 to 3 inches, to allow
for future adjustments of the cable.
Press a new ferrule onto the tip of the cable. Squeeze the ferrule
onto the cable using pliers.

from: http://www.ehow.com/how_7706040_replace-shifter-cable-shimano-105.html


Short answer: Yes easy.

My recommended process:

If you are the original owner of the bike check out SR Suntour's upgrade program.

https://www.srsuntour.us/pages/upgrade

The RAIDON XC-LO-R 26 with a straight steerer would be a really good fork for that bike at $199 down from $299 with the deal.

If that isn't appealing you'll want anything that has support for a 26" wheel, 100mm of travel, and a straight 1 1/8" steerer. I doubt you'll be able to fit anything over a 2.3-2.4" tire in there.

Note: For the fork from SR Suntour I mentioned, it has a 160mm flat mount support for brakes, so you'll probably have to upgrade your front rotor to a larger size as well.


Do I really have to replace the cassette when I replace the chain, or is this a scam?

At our shop, we suggest a new cassette every 2 times you replace your chain, IF you stay on top of your maintenance schedule. With 99% of customers this would mean a new cassette every 1-2 years depending on how much you ride it. If you are a commuter and ride everyday, your timeframe for replacement gets much smaller.

We would also assess the condition of the bike. If it looks like it has been neglected, we can, with high confidence (we do hundreds of these bikes a year), tell that you would need a new cassette as well.

What I tell every customer in your situation is as follows:

  A chain that is not cleaned regularly will attract and hold dirt. That dirt will act like 50-grit sandpaper on everything it touches. When the chain stretches out, it will wear the cassette equally. If we try to put a new chain on a worn out cassette, the teeth on the old cassette will match the old worn out chain and won’t properly hold the new chain. We recommend replacing the cassette for every 2 chains so we can guarantee shifting performance from our tune. If replacing the cassette is something you want to hold off on we can try to put a new chain on the old cassette, however we may find that we can tell what your favorite gears are and it may skip under load.

You can always ask them to just put a chain on, check to see if they can make the adjustment, and call you if it is skipping or poorly shifting.

However, since your chain and cassette were only a month old when the chain snapped, unless you have a bent/broken tooth on your cassette, it should be good if everything else is adjusted correctly.

As far as the snapped chain, it may come from manufacturer defect, improper installation, or you may need to revise your shifting strategy.

  You want to make sure you’re not cross-chaining. This will put a lot of stress on the components and will wear things out quickly and possibly snap your chain. Also, your bike doesn’t have a clutch, so you have to back off on power when your shifting. Right before you’re about to shift, let off pedaling a bit and wait for the gear to change. This will increase shifting speed and accuracy.

We do see a lot of customers resolve shifting problems with proper information on shifting. (If you’re shifting the proper way, then disregard. It’s more for people who will view this post later.)


It's (a lot) harder to achieve in-out motion than side-to-side, and generally requires (much) more that 1/2 turn adjustments.  Plus you must usually loosen spokes on either side (2-4 spokes away) of a high spot, or tighten spoken on either side of a low spot.  For low spots sometimes you need to tighten ALL the spokes except those over the spot.

But at some point you need to either scrap the rim or employ a tool to bend the rim.  Bending out low spots can be effectively handled with a jury-rigged tool consisting of a couple of blocks of wood with holes drilled in them and a piece of "all thread" with a couple of nuts and washers.  (I've never dealt with high spots serious enough to require the opposite tool.)


How to choose between a race bike like a Madone and a classics bike like a Domane

I think you answered your own question when you stated "I don't race."  I know many in our club who enjoy the Roubaix.  I personally prefer riding my steel Soma ES over my carbon race bike for most things, including fast club rides.  Don't get me wrong, a twitchy race bike is great in a crit, but the other non-race bikes have had their design optimized for non-race road riding.  It is too easy to get up caught up in all the bike porn the industry pushes.  A solid, well sorted, well maintained, properly fitted road bike of any class and age can be a great riding tool.

In the end this is just all opinion, but I would be careful not to get caught up in the industry's push for "race" performance, which only serves a small minority of road riders.


Racing bike feels bad to ride, can it be fixed?

Pro XC racers often like a responsive bike. 'Twitchy' in the hands of a pro is fast. My guess is you are used to the 29er and the new bike is a 650B - 29ers like straight lines and turn like beached whales. If you are used to a 29er, anything remotely responsive will feel twitchy and take a bit of getting used to. I had the opposite problem moving from 26 - 29er - same end result - crashes and swearing for the first few rides.

There are things you can do nothing about -geometry, wheel size, things that cost a fortune to change - fork rake, and low cost fixes. Low cost fixes I would look to first are stem length (Increase to reduce responsiveness) and wider handle bars.

Tires and tire pressure.....

Zero cost fix is to keep with the bike till you get used to it...

Edit:
Play with shock set up and tire pressures and see if it helps. "Twitchy" could be too much rebound (not enough rebound dampening) - are you experienced enough to have a feel of how the shock/tire/track interactions are working?

Its really hard to provide an answer as there are so many things we cannot know about you, the bike set-up, the trails you ride etc.  In the end the fastest way to a solution is visit your LBS and get a bike fit, explaining your problem. A good bike shop will be able to sort you out, or at least, tell you what is  wrong.


What is the recommended type of tire for riding on wet pavement?

If you are riding on the road, slicks are fine in the wet. If you need to go over any mud, etc. then you'll need something else.

From Sheldon Brown:

  Bicycle tires for on-road use have no need of any sort of tread
  features; in fact, the best road tires are perfectly smooth, with no
  tread at all!

  Unfortunately, most people assume that a smooth tire will be slippery,
  so this type of tire is difficult to sell to unsophisticated cyclists.
  Most tire makers cater to this by putting a very fine pattern on their
  tires, mainly for cosmetic and marketing reasons. If you examine a
  section of asphalt or concrete, you'll see that the texture of the
  road itself is much "knobbier" than the tread features of a
  good-quality road tire. Since the tire is flexible, even a slick tire
  deforms as it comes into contact with the pavement, acquiring the
  shape of the pavement texture, only while in contact with the road.

  People ask, "But don't slick tires get slippery on wet roads, or worse
  yet, wet metal features such as expansion joints, paint stripes, or
  railroad tracks?" The answer is, yes, they do. So do tires with tread.
  All tires are slippery in these conditions. Tread features make no
  improvement in this.

Also worthy of note is:

  Car and truck tires need tread, because these vehicles are prone to a
  very dangerous condition called "hydroplaning." This happens when
  driving fast in very wet conditions, which can lead to the tire riding
  up onto a cushion of liquid water. When this happens, there is a
  sudden and total lack of traction.

Bicycles can NOT hydroplane because:

A bicycle tire has a curved road contact. Since a bicycle leans in
corners, it needs a tire with a rounded contact area, which tends to
push the water away to either side.
A bicycle tire is narrower, so not as much water is in contact with
the leading edge at once.
The high pressure of bicycle tires is more efficient at squeezing the
water out from under.
At high speeds, hydroplaning is just possible for car tires, but is
absolutely impossible for bicycle tires.


r9000 Dura Ace inner chainring vs r7000 105

There are component tables on the tech website you can look up, but the short answer is yes, it will work as intended for shimano manufactured rings.
People seem to wear out the 50 outer ring quicker on Road as it's used considerably more than the 34, so don't worry about durability too much. Keep your eye on chain wear like normal to extend ring life.


What features should I look for in a mudguard?

Mudguards / fenders work by intersecting an imaginary line between your wheel and you/the bike frame.

There are two main reasons for having them and they're similar but different.

Keeping your bike and rider DRY from water
Keeping your bike and rider CLEAN from mud/dirt

In addition mudguards might offer an increase in aerodynamics, and somewhere to hang more lights/reflectors.

So the best mudguards will look something like this:

The rear mudguard starts after the rear tyre.  So there is no straight line from the tyre to the rider or backpack.
The guard is close to the tyre, so spray can't flick off the sides of the tyre, evading the guard and hitting the rider under the thigh.  My ass-saver does none of this.
At the front of the rear mudguard, it does right down to the chainstays.  This somewhat-protects the bearings of the BB and your chain and chainrings from spray.
Up the front, the rear edge is quite low too, and this protects your face and front from upspray when turning.  It also shields the BB somewhat.
But in addition there's a mudflap behind the front guard.  This dangles and helps catch roadspray that would hit your chain/chainrings and BB housing.  Mine's made from a leather tongue from some worn shoes.
Finally, the front/leading edge of the front guard goes forward of the front wheel axle.  This stops water from being thrown forward or slightly upward and catching the wind, coming back either into your headtube bearings, your hands, or your chest and face.

The only thing missing is a flap on the rear guard - this is more for the benefit of someone riding behind you though.

A second downside, this style only works on rigid bikes.  If you have suspension then your guards can't be too close.

Notice the rear guard is fastened to the rear triangle, so as the suspension flexes, the guard stays in the same place.   The front guard is much shorter because it can't use stays for support, and is a very long way from the tyre.
The tyre/guard clearance has to be bigger if the bike is likely to be ridden in mud too, else there can be a buildup of mud enough to stop the wheel turning.

The MTB guard has to be much wider too, because the tyre is wider.  Knobblies catch and throw a lot more water/mud/stones than smoother road tyres.

As such, this offers much less protection from water and mud.

Materials will probably be either metal or plastic.  There are wooden ones, but they're not common.   Metal ones can suffer from stress fractures due to vibration, so more stays work better.  Plastic ones are a bit more forgiving, but they crack slightly easier than metal and can embrittle with UV/age.

A final option is a home made hack.  All you need to do is intersect the flying droplets.  So search and you'll find fenders made from strips of plastic, old bottles, even tyres with the bead cut off.   If you have a rear rack, simply line it with flat plastic and you've got protection


What variables are considered when determining wheel size and how do they affect these variables?

The first variable is the size itself. When talking about folding
city bikes, they have to be as compact as possible so you can take
them as normal luggage when folded.
There's also the aspect of weight - smaller wheels are lighter but
also have lower rotational inertia. This means they are easier to
accelerate but once they gained speed, they don't hold it for quite
as long as large wheels.
In mountain bikes the wheel size is a very individual thing. Smaller
wheels offer better acceleration an better maneuverability (such bike
is generally shorter and of course requires less force to turn a
wheel). On the other hand, large wheels give better angle of attack
meaning it's easier to roll over any terrain obstacles. Also, on a
larger wheel you can have larger contact patch giving better grip.
There's also a question of stiffness, Small wheels, especially in
cheaper ranges are stiffer because of shorter spokes used.
In most disciplines of cycling the wheel diameter is 550-650mm (not
too precisely), so the differences are not enormous. Smaller wheels
are used in folding bikes and BMXes - in the latter because of easier
handling of a sherter, lower bike both on the ground and in the air.
I've partly mentioned the changes in bike geometry, but I'd like to
make it clear - wheel size can affect your position on a bike. In
particular when really large diameter wheels are used, handlebars
will be up pretty high and there's little you can do about it with
manipulating the frame geometry.

There's no single standard of wheel size for any bike types, which shows that manufacturers change their approach and priorities over time. It's also hard to determine the perfect wheel size for each person (talking about MTBs here), because it depends on people's personal preferences, experience and use of the bike.


How do I mount rear derailleur on frame without separate hook part?

Some Tourney derailleurs have a sort of extension ('hook' as you call it) that your new Acera derailleur does not. That is fine. The Acera derailleur simply bolts to the derailleur hanger on the frame (the piece if metal pointing downward in your first picture)

Your new Acera derailleur has what is known as a 'B pivot' which I believe the Tourney derailleur lacks. The B pivot is located where the derailleur bolts to the frame. The entire derailleur rotates around the B pivot, the B pivot spring tries to rotate the derailleur anti-clockwise underneath the cassette.

(There is also a 'A pivot', around which the jockey wheel cage. rotates.)

The blue painted screw you mention is the 'B screw', which is used to adjust the position of the derailleur about the B pivot. It is likely that your B screw simply needs to be adjusted properly so that the derailleur is moved away from the cassette

You can look up instructions on how correctly the adjust the B screw. Park tool has a good video on derailleur adjustment which includes B screw adjustment.


You'll need a new chain, since the chain will be slightly longer.

You need to see what the ratings of your rear derailleur are. It has to have enough capacity (i.e. the capacity rating has to be greater than or equal to large chainring - small chainring + large cog - small cog) for your setup. It also has to have appropriate ratings for the largest and smallest cog (i.e. the smallest cog rating has to be <= your smallest cog on the cassette [this is practically never a problem], largest cog rating has to be >= the largest cog on your cassette). If your RD meets these, great.

If your rear derailleur doesn't meet these, well, you need a new one. Here you have to match the cable pulls. Shimano 7-9 speed have the same cable pulls between road and mountain so you can use any RD in the 7-9 speed case, if you have 7-9 speed shifters. Shimano 10 speed mountain uses a different cable pull than Shimano 10 speed road (which is the same cable pull as 9 speed).