Realign the cassette gears after removing the rear wheel

Normally, when removing a rear wheel, I shift to the small-small combination since this gives the most slack and gets the rear derailleur out the farthest. (Obviously, this doesn't matter for a front wheel). Then, when putting the wheel back on, put it on in the small-small combination and shift out of it when you've tightened the wheel down.

You need to make sure your wheel is seated all the way in the dropout. If you have horizontal dropouts, this means all the way back up to the little set screws which tell you how far back to put the wheel (you don't need to re-set the set screws). For vertical dropouts, this means all the way up in the dropout.

If the wheel was in properly and the gears were aligned before removal from the dropout, they should be still aligned when you put the wheel back in. In the case that the wheel isn't aligned properly, either your derailleur took a hit at some point, the wheel/tire is somehow hitting the brakes, or most likely, you didn't put the wheel in the dropout properly. (I suppose frame damage is also a possibility, but this would have been something you noticed before removing the wheel)

Try re-seating the wheel in the dropout. If you're sure you've got it in the dropout correctly, follow the instructions on adjusting your rear derailleur here.


I'm just going to make a list of all the factors I can think of that affect stability, but please be aware that this list is not exhaustive.

front tyre size/width
front tyre weight
front tyre pressure
front wheel size
front wheel rigidity
headset angle
trail
front fork rigidity
front fork travel
front fork suspension friction
front suspension travel shape
front fork preload
stem length / handgrip position relative to steering pivot
handlebar rigity
grip size and firmness
primary frame/main triangle rigidity
main triangle size and angles (affects BB to handlebar and seat position)
rear triangle rigidity
rear suspension type
rear suspension travel
rear suspension travel shape
rear suspension preload
slop in suspension pivots (all six axes)
slip in all the other bearings - headset, bottom bracket, wheel axles etc
BB to ground distance
seat height
seat front-back position
seat firmness
Q factor (BB/crank/pedal spacing)
chainstay length
rear wheel size
rear wheel rigidity
rear tyre size/width
rear tyre weight
rear tyre pressure

I am certain that I have missed some, and a few of the entries above should really be split out a great deal more - the rear triangle could be made of composite materials allowing fine, semi-independent control over rigidity in different axes, for example. And vertical compliance of the main triangle is a subject of intense discussion in some cycling circles. Likewise, suspension design is a complex subject that's quite different from suspension tuning, but I've largely conflated them in the list above.


The GT Aggressor 2.0 2014 ships with a rear wheel which uses a freewheel, so if you want to go 9 speed, you need a rear wheel which has a Shimano-compatible cassette freehub as well as a 9 speed rear shifter which is Shimano compatible (and obviously a 9 speed cassette).

Buying a new rear wheel will be likely cheaper and more reliable than having the existing rear wheel rebuilt with a freehub. A 9 speed cassette freehub can use a 7 speed cassette with a spacer.

However, I'd recommend against the whole idea -- by the time you've done this, you've spent likely half the cost of a cheap bike like the Aggressor 2.0 and with the low spec of the rest of the bike, you're not really going to see performance gains (especially for the amount of money you're spending). If you want 9 speed, sell the bike you have and buy something is 9 speed already.


Be careful about the expense. 26" makes this a 10 year old bike. While each change over that time has been small, end result is geometries and performance of bikes have significantly changed in that 10 years,  My sons entry level $1k softtail is in many ways a better bike than my 9 year old Carbon Scott Spark 10. The cost of the upgrades and selling the old bike would go a long way to a new bike.
Unless the old rim is in excellent condition, threading a new hub onto an old rim can be difficult to get a good build. Personally I would avoid doing if at all possible. You would be better to buy a new (new old stock) 26" rim. (The rim cost will be small compared to the labour of wheel building and new spokes. In the unlikely event the  old spokes are the right length, reusing 10 year spokes is not recommended.)
The Sunrace 11-51T cassettes are not bad, provided you use the right one. Ideally stick to the same manufacturer if you want bet performance, which means micro spline if you want 12 Speed Shimano
Have you considered 11 Speed?  You can get an 11-51 in Deore.
You can replace the middle chain ring, you may need short chain ring bolts.  With narrow/wide you can probably remove the front derailleur and not drop the chain - but as always, YMMV.  The chain line will be correct.


Terry front wheel (ISO 520 vs 540), big difference?

Interesting—Sheldon Brown's tire-sizing chart refers to the 540 size as "British juvenile or wheelchair"

In any case: The 520 wheel (which his chart lists as the Terry size—looking at the Terry website, I see they sell both sizes) will pitch you forward slightly and give you a slightly steeper effective head-tube angle. I don't think that would be a big difference. And you'll need to adjust your brake pads. In theory the size difference could be offset by using a fatter tire, but in practice, I think fatter tires are not made for the 520 size.

I've never heard of anyone using a wheelchair rim on a bike—the only possible downside I would imagine might be A) if they aren't available in the spoke count you want, or B) the braking surface.

You might contact Terry directly and see what they think.


You've really got a few things going here.

For going up hills easier, you have 2 aspects for a given bike:

Bike geometry and bike fit: If the geometry of the bike is not good for climbing and/or you're poorly fit to it, its going to be harder than necessary. So play around with adjusting your saddle height + position + stem + handlebars.
Gearing: For going up a hill, you want a low gear (big cog in the back, smaller chainrings in the front). Your tire size does play into this a bit, but its secondary (bigger tires = higher gearing). You can use something like this to calculate gearing.

So, if you want to make it easier for a given bike to go up a hill, fit a cassette/freewheel with bigger gears, and use smaller chainrings in the front. Note that lower gearing means that your top speed won't be that high.

When descending a hill, you also have two things:
- Bike geometry and bike fit: The position of you on the bike and the geometry will determine the stability and control you have when descending.
- Brakes: Brakes are the way you'll primarily stop. If its a big descent, you have to be careful not to overheat the brakes/rims, so you need to choose appropriate brakes (this includes pads, calipers, etc.) that provide the right level of braking for the weather/terrain and modulate them appropriately (e.g. if you go down a long hill and just hold the brake partially on, you may boil your brake fluid on a hydraulic brake, just like you would on a car).

Your gearing won't necessarily matter all that much on a bike with a freewheeling mechanism, since you'll either have a gear that you can accelerate with or you'll be freewheeling (and if you want to accelerate, you'll want to add combinations of higher gears (large chainring, small cog in the back)).

Tires: For road use (on a clean/wet road), you want smooth tires. Knobbies increase resistance on a road, plus when cornering at high speed can flex and lead to wiping out. Also set your tire pressures correctly (this is important for comfort and control). Off-road or snow will favor some form of knobbies. As for tire sizing, note that it does affect the standover height a bit, but this is a personal preference determined by how much you weigh, how much comfort you want (bigger tires at lower pressure are more comfortable), how well the tire stands up to cornering (which is determined by how flexible the tire is as well as the pressures its run and its size -- a big low pressure tire may flop off at a high speed corner when a thin high pressure tire wouldn't), puncture protection, rolling resistance at a given inflation pressure among other things. Note that you don't want to run a very wide tire on a very narrow rim and vice versa due to the tire coming off or hazards damaging the rim.

Unless you're riding on a road and you have knobby tires, I'd probably start with finding appropriate gearing (by swapping freewheels/cassettes so you have a big enough big cogs for the uphills and small enough small cogs for the downhills) and making sure brakes are up to snuff (probably starting with having good brake pads and the brakes are in adjustment). If you are riding on a road and have knobby tires, buy some slicks.


What's the best way to quickly align front quick release wheel?

What I worry about mainly is the horizontal alignment of the wheels and brakes (V brakes or disks). In my experience just pressing fork down on the wheels will then "auto fit" which creates an horizontally accurate alignment.

I press from the handlebars vertically to the ground and the wheel keeps an horizontal alignment with the brakes (accurately set). The operation to press and lock the wheel takes 10 seconds, no more.


Andel crankset, BB axle length and chainline

It will be 3.5 mm off, and that is quite bad. Square taper bottom brackets aren't that expensive or difficult to replace, just get a correct one.


What causes the threads on bike pedals to become stripped?

It probably means that the pedal was never installed correctly: either it was not tightened enough or it was cross-threaded.

It's actually not that hard to install a pedal incorrectly. If you miss perfectly aligning the threads, it's called cross threading. It's possible to cross thread the pedals and still have them feel like the pedal look like it is installed properly.

However, if you look closely, you'd see that the pedal isn't perfectly perpendicular to the crank. When you pedal, you'll feel a pop as the pedal goes around when your foot crests and the pedal (due to not being parallel to the crank) has to change orientation.

Over time movements of the pedal relative to the crank will slowly strip out the threads on the crank, on the pedal, or both.

I could speculate that your raleigh may have been purchased at a department store, and that it wasn't assembled by a professional. They didn't install the pedal correctly.


This can be a regional thing, but here in Germany, many are happy with Ballistol applied as aerosol and not changed during the seasons.

From a material science perspective, its viscosity is very low and has little temeprature dependence. It is also said that it is environmently friendly, to the extend that you can use it on pets, which I never tried as I found chains on my bike much more suitable.


Accommodation (or "breaking in") of cycling shoes

Breaking in shoes is a personal thing.  Some people can wear anything straight away, some people take ages.  I had a set of boots that took over a year to become comfortable but they lasted for a decade.

You don't need to be riding to break them in.   If you can, wear these shoes at work or while sitting down, will help the shoe conform to the foot.  This becomes harder if the cleats are exposed, but MTB shoes are often recessed for increased walkability.

Leather is an interesting choice - if you treat it with beeswax or dubbin then it will become more soft and pliant.   Regular routine application of nugget helps preserve them and maintain water resistance.


On a full-suspension bike, the rear chain- and seat-stays are attached using pivot points. However, what attaches to the dropouts on the chainstay? The wheels. The chain's route is constantly changing as the suspension travel changes. If the suspension is fully compressed, the distance from the wheel to the pedal decreases. If the suspension is fully de-compressed, the distance increases. This essentially changes the amount of chain links between each side. If the increase is sudden, which the back wheel moving at a constant rate, it'll either increase the free-hub/wheel speed or will 'kick' the pedals back. It's an un-nerving feeling, but it essentially means that you're, in a sense, pedaling without actually pedaling as your force downwards is kind of amplified as though your gearing has temporarily changed. However, when the frame pivots re-extend, they usually over-extend before settling, undoing all that awesome work that the pedal-kickback has just done for you.

This is a painfully hard topic to explain in words, and is usually only suitable to be taught using illustrations and videos, so here's a photo I've found from the internet:

This image is from: "https://polebicycles.com/wp-content/uploads/2015/06/Pedal-Kickback.jpg"

It's a bit math-y, but hopefully it'll help you understand how it works in a sense.


There are many designs of pedal pins.  Some are tiny bolts coming through the pedal body and fixed by nuts on the opposite side, some are instead screwed directly into the pedal body, into blind threaded holes, and some have flanges to control the depth on insertion. Some are seemingly pressed into the pedal body without a possibility to be replaced.
A few of many existing designs are shown on the pictures below.

It is often possible to buy replacement pins that are physically longer so that when installed, they protrude more from the pedal surface.
Other designs, mostly "screw through", may allow to install a shim on the opposite side, thus making the pins shorter (not longer).
For those designs where pins are screwed directly into the pedal body from the "front" side, their incomplete threading makes them protruding more. However, fewer threads will hold them in place. It will incur higher risk of losing pins but also damaging their threaded holes in the pedal body, making installation of replacements problematic. I would not recommend doing so, and instead would seek for longer aftermarket pins.
Finally, longer pins are only needed to get better grip on the soles. Instead of changing the pins, it may be worth trying to increase the grip of the shoes instead. There are many inexpensive MTB-specific shoes, whose grip on pins is much better than of e.g. running shoes.


Is the Shimano SL-M590 shifter compatible with XTR RD-M900 rear derailleur?

Your information is a little out of date, but for 9-speed, all road and mountain rear derailleurs and shifters are cross compatible from xtr and da to Alivio and Sora.
Other combinations work to but for the purposes of your question, there are no issues or likely problems from your component selection.


Suitable remedy for chain damaged by bike shop

@Alexander is right, there is no need to break a chain when you replace a bottom bracket. So your hypothesis doesn't make complete sense, unless maybe they were doing other stuff to the bike?

So if you do take the bike back to the shop, odds are that that's their response.

I know if I got myself a new (second-hand) bike, I'd think about replacing the chain almost automatically. Same as something like brake pads. Just so you know where its come from, plus they're cheap enough its almost a no-brainer.

By the looks of that cassette its an 8-speed, so you just need an 8-speed chain (e.g. http://www.kmcchain.eu/?en/products/multiple_speed/8_speed_derailleur/). Really common, any bike shop will have one. If you decide to buy off the web and fit it yourself (easy enough, just need a chain tool, which is an invaluable tool to have in any case), actually KMC is a decent brand to go for anyway.


In shared bicycle/pedestrian facilities next to a road, do I obey the pedestrian or the vehicle traffic control devices?

Honestly, I think that's a crappy design for a bike path, and I would just ride in the road instead.  A bike path like that is great for a weekend ride, but for a daily commute, it just wouldn't cut it.

If that road isn't safe to ride in, I'd try to find a different route.  And if that's not an option, I suppose I would probably ride against the pedestrian light, slowing down to make sure it's safe to do so.


Ice tires for winter commuting on non-icy roads?

I think the tires would be durable enough (my winter commute in nearby Kitchener, ON is about 20 km/day and my Marathon winters hold up pretty well) but they're definitely going to feel more sluggish than a road tire.

If you're normally running them with enough air pressure to keep the studs clear of the pavement, I think that kind of defeats the purpose of them (and that much pressure makes the ride a little harsh for my liking as well). Carbide studs will last as long as the carcass of the tire holds together, and there's always a chance of running into an icy patch somewhere, even if 99.5% of your route is bare and dry.


How should I clean salt out during Winters?

You can use water to remove the salt if it's bad enough, but immediately wipe off the water and generously re-lubricate the chain. You do not want to let the chain sit around with the salty water on it, as it will readily rust. So if you use water, just make sure the chain is completely dry afterwards, then re-oil it.

Metal doesn't really get porous, but AFAIK rust kind of does-- if the rust is that bad, you may want to consider cleaning the rust off with a toothbrush or getting a new chain altogether.

Oiling often in winter is a must. Some people use hot wax instead, but depending on your situation, that might be overkill. You may not need to oil it every day (if it still has plenty of oil visible on it, I don't bother with my chain).


You've got two things going against you:

Height: I'd suggest avoiding 700c wheels and going for 650b (pricer) or 26" wheels. For short riders (I'd say shorter than 5'5"), these provide better fit. Surly, for example, only makes their small bikes with 26" wheels.
Weight: You're going to have to check each manufacturer's weight limit. Generally, hybrids and mountain bikes will be rated up to 300 pounds. That being said, expect more risk broken spokes and rim damage if you hit a road hazard. Cheap wheels are going to be your primary adversary. You also want big tires so you don't have to run them at insane pressure (which can increase chance of wheel damage) to avoid pinching the tubes (unfortunately, big tires increase the standover height, which can be a problem for short riders). On the road (and light off roading), you don't need suspension (and for high weight riders, you're going to load the suspension unnecessarily, especially on cheaper stuff).

My recommendations are:

Find a bike shop in your area to buy the bike. With high weight and low height, online bike buying isn't going to be very good for sizing or comfort and you'll likely want to swap out some parts on a stock bike anyway (saddle, tires come to mind). And most people won't ride a bike thats uncomfortable.
You may want to buy upgraded wheels (or more likely, upgrade wheels when the ones that come with the bike may start to fail). In general, don't cheap out. Reading Peter White's page on wheelbuilding is a good place to start.
Look for bikes with no suspension that can take big tires. 700x32 minimum (preferably 35 or 37) if you choose to go 700c wheel sized (though I recommend 26"). 26x2.0" for 26" is ideal. Hybrids, mountain bikes (front suspension is OK but no suspension is better; swap on slick tires) or touring bikes are all good candidates. Cruisers are also not a bad choice, since a lot of them have step-through ish frames which can be easier to get in and out of. Step through and mixte frames in general are good idea for shorter riders (mixtes being stronger than normal step through frames).
Don't buy a bike just cause it looks cool.
Men's bikes work fine for (most) women. Most of what makes a women's bike is maybe a slightly lower top tube, a wider saddle and a ridiculous paint job. That being said, some women's bikes do have better specs for women (Trek's Shift line has 26" wheels, and their mountain bikes aren't all 29ers, though this seems to be happening on the mens side too).

You may want to look at bike forums with sections like "athenas or clydesdales" -- these are typically heavier riders (clydesdales are generally men over 220 lbs, athenas are women over 165 lbs). Example is this one. If you're upgrading components, they may have specific recommendations which may be useful.


I like to use an excellent power calculator to answer questions like these. Play with the numbers, and you can see the exact effects on wind resistance of different rider positions or changing the type of tire.

In short, at race speeds, wind resistance requires by far the most power to overcome. It ends up being anywhere from 85%–90% of your overall power expenditure. For example, with that calculator, it takes a fully-crouched 150lb rider somewhere around 650W to maintain a 35mph pace. Remove air resistance entirely and it only requires an astonishing 50W. At the same power output (650W), with no air resistance, the same rider could reach a ridiculous speed of 475mph.

Sheldon also covers the topic, providing an excellent cost–benefit breakdown for various aerodynamic improvements. And Wikipedia makes the claim that "lowering a bike's weight by 1 lb… will have the same effect over a 40 km time trial on flat ground as removing a protrusion into the air the size of a pencil".


If they don't sell/manufacturer them anymore, then your best bet might be the used market, such as Ebay.  This article has some interesting information.  It seems like it's possible to mix 6770 and 6870 parts if you haven't updated your firmware. Otherwise it says something about using 6870 derailleurs with 6770 levers. Which I think means you could upgrade your entire drivetrain to 11 speed, without changing the levers, which would make the upgrade a bit cheaper. You could probably keep your crankset the same as well, as I'm pretty sure that it would be compatible.

I don't have Di2 and I'm just going by what I've been able to find on the internet.  Do some more research. There's probably a good solution that doesn't require upgrading the entire groupset. I read a few other other articles while searching around, and it seems like Shimano did a pretty big disservice by dropping the 6770 product line.


Slime Smart Tube Exploded when I put it on mountain bike

I can think of three scenarios that caused your issue. The tire was damaged from running flat before you got it. While installing the new tube it was pinched between the tire and rim. After inflation it lifted the bead off the rim resulting in both the tire and tube failing. The tire was grossly overinflated resulting in the tire sidewall and bead separating.


Well, a google image search of my image came up with Norco.


Before re-inserting a stuck seat post what should I do to the steel/alloy surfaces?

I would not advise reducing the seatpost, nor widening the frame's ID.   A close fit is a good thing for a seatpost.
Instead, clean the seatpost using your preferred solvent, and allow to dry.  If its not smooth, a very light buff with medium/fine sandpaper would help, but you're only taking off the bumps.
If the post has nicks or damage, then you may need to do some localised hand filing and then sand smooth.
As for the steel frame, it likely has iron oxide in the seat tube, AKA rust.  I would start by using a small ball of rag or a cotton ball on a stiff wire, to "paint" the inside using a rust reformer.  I personally use a Phosphoric-acid based product called "Rustbuster" but there are many other options.
Your aim here is to chemically inert the rust, and replace it with a more-stable oxide.    Do note this stuff will dull paint, so wipe up.  It will also dissolve your skin, so gloves, and use it outside, with eye protection.
I'd lay the bike on its side and work the inside of the tube.  Then flip the bike and do it again.  This should minimise chemical getting down onto the bottom bracket and bearings/races.  If you have a cartridge BB, this is much less of a problem.
Leave the product to cure as per label - mine takes anything from an hour to a day depending on how thick the rust is.  A bike tube will only have thin rust.
Then get a suitable 10mm or 3/8" wooden dowel, and cut a slot in the end.  Slip a piece of folded sandpaper in so that as you twirl the down in your seat tube, the abrasive rubs the inside.  Mount the other end in a drill chuck and "whiffle" the inside of the tube while moving the sandpaper back and forth.  It won't take much.  Then give the tube a clean with some air or tap it upside down to get all the dust out.
On refitting your seatpost, use grease or similar.  I have a copper/clay based product that works well, and repels water too.  You only need a thin layer, and only as far up the seatpost as will go in the frame.
Prevention Often I've found the reason for seatpost corrosion is water in the wrong place.  The two ways water gets there is either

Rain/road spray/fog/sweat/etc dribbles down the outside of seat post and wicks down inside the collar, and/or
The bike has a slotted hole in the rear of the seat tube for the clamp to compress.  This slot collects road-water thrown up by the back wheel, where again it wicks into the joint.  This is worse if your area uses salt on winter roads.

Mitigations could include fitting a rear mudguard/fender, reducing water ingress by adding grease to the area, or fitting a short piece of old inner tube over your seatpost and then down over the interface to the frame (once your saddle height is dialled-in of course.)


May I ignore the frame damage (or should I get a budget carbon frame)

My guess is the alignment was like that before the accident and the reason the gears wont adjust is the derailleur hanger is bent, which is a $10 part and/or a visit to the LBS with a tool to fix it.

Even if the frame has been bent, although less than ideal, it is not a safety issue and would not stop me using it - as long as the derailleur hanger can be aligned correctly.

However there may be other more critical, but less obvious damage (cracks etc), that you are not aware of, and this be the reason for the insurance write off.

As for going to carbon frame, for the same money you are almost certainly better off with a steel or alloy frame. Cheap carbon, like everything, is cheap for a good reason. As Carbon is seen as a material with God like qualities by many novices, it commands a price premium based on that perception at the budget end, its until you are paying mid range prices that carbon really shines.


My crank fell off, how do I re-attach it?

In general, crank fixing bolts need A LOT of torque.  This chart list torques for several varieties of crank arms.  (I suspect you have a variety of Octalink.)  You're probably looking at something in the neighborhood of 350 inch pounds, which would be 35 pounds applied to a 10-inch lever arm.

Too much force and you shear the bolt.  Too little force and the arm works loose again.

The torque spec embossed on the bottom bracket cup is most certainly for the cup, not the crank arm.

Unfortunately, if your crank arm fell off I suspect it's been damaged, and is apt to no longer fit tightly, no matter how tight the bolt.


Beginner bicyclist question about purchasing a new road bike

Welcome to cycling. 325 bucks is really not too much for a complete bike (you'll understand this better later on). So, go for it as long as the sizing is correct for you. If you are not sure about sizing, take the bike to an LBS and have them do a (paid) assesment and fit in case you buy it.


Unless you're out derbying or have a complicating balance issue I wouldn't worry about it.  Falling off a bicycle when commuting or recreational riding should become an extremely rare experience with practice.  Tank tops and shorts are perfectly acceptable bike wear in the summer.

Ice is of course a different beast; the best advice I have for ice is that you should be prepared to fall and do not have anything in your pockets that you don't want embedded in your leg.


I had a similar issue last year. The threads on the frame to take the bottom bracket were too worn to hold the bottom bracket in place. A bike mechanic should be able to confirm this for you (for no fee). After some research I found two solutions, one of which is considerably cheaper than the other:

1: bike frame specialists / frame refurbishers can re cast the frame thread with a tough resin, and then rethread the resin, allowing a bottom bracket to sit securely. This is the expensive option.

2:You can buy bottom brackets that tighten onto them selves to stay in place. This is a sample: http://www.kingstreetcyclery.com.au/self-tightening-bottom-bracket-u118.html
However! do your research before you buy; there are different spindle lengths and other options. I replaced mine with one from ebay for about £40. After retightening a few times initially, I have had no problems since.


Are front and rear tires on BMX bikes interchangeable?

Look at the sidewall of the tire if it is marked front or rear the tire is designed with a specific position in mind. It may also include rotational direction arrows. Without any marking I assume it is a multidirectional and multiposition tire.


If you have proportionately short legs and a long body and arms, I would recommend against buying a bike unseen. You really need to test ride some bikes and get an idea of the geometry you need.

You’ll need is bike that has a sufficiently long ‘reach’ (horizontal distance between bottom bracket and bars) so that your upper body is not cramped, but a short enough seat tube so you can set a shorter bottom bracket to seat distance. You probably also want a short ‘stack’ (vertical distance between bottom bracket and bars) so the bars are not too high.

You’ll need to seek out and try a number of bikes to find a model that suits you.


Are 700 x 28 , 700 x 32 and 700 x 35 tires interchangeable?

You can (theoretically) mount any 700x(something) tire on any 700c  (ISO 622) rim. However, you need to make sure the frame (and brakes if rim brakes are used) can clear the tire without rubbing.

You generally want to match the rim width to the tire though -- too narrow or too wide of a tire on a rim can lead to tire/rim damage or bad handling.

In your case, the rim width is 17 mm and the chart linked above says 25-37 should all be fine.

As for overinflating, why would you overinflate? You will use a higher pressure with a narrower tire, but overinflating means putting too much air in. And this can be bad for the rim. The right tire pressure is not whats written on the sidewall of the tire -- in fact, you'll almost never use that much pressure. We have many questions on tire pressure setup, so I encourage you to use the search feature to look at some of them.


Finding which gear on my bike is closest to a single-gear bike

We can't tell without more information about your gears.

However, you can figure it out for yourself quite easily, by looking at the ratio of chainring teeth to rear sprocket teeth on the single speed bike (the most common I've seen is 44/18 = 2.44).

Then you just need to figure out the size of your current bikes chainrings, the size of the sprockets on your current bike, and calculate all 21 gear ratios, and find which is closest to the single speed ratio.

If I had to guess, I would say it would most likely be equivalent to your middle chainring (39 teeth?) and somewhere near the third smallest rear sprocket (16 teeth?) because 39/16 = 44/18.

Of course, you can almost always pick and choose the gearing on a single speed bike, so realistically you yourself get to pick "what gear on the 21 would be for a 1".


It sounds from the audio like the tyre is rubbing somewhere. The sound is certainly related to the wheel because the frequency speeds up and slows down with bike speed, not pedalling.

You say the tyre isn't rubbing, but the sound doesn't happen when bike is unloaded, so perhaps when it is fully loaded, the frame is flexing enough to cause a rub - is there any point like behind the downtube or close to a mudguard or chain stay where the tyre is close to something? Then when it is loaded up it is able to rub.

It's also making the noise once per revolution of something (the wheel) so something is out of balance. Maybe the wheel isn't true, radially or laterally, or the tyre is bulging at one point on its circumference.


Mountain bike front derailleur won't shift up

First follow the cable run from the shifter to the derailleur and check the cable housing is properly inserted in the shifter and all frame stops. If the housing is not secured the shifter cannot pull the cable to activate the derailleur.
Check the derailleur has not been rotated on the frame. This is easily done by bumping the bike into something. The cage should be parallel to the chainrings
Detach the cable from the derailleur, tension the cable a little by pulling on it with a pair of pliers, work the shifter and make sure it shifts through all gears and pulls in and lets out the cable smoothly.
With the back wheel of the ground, manually pedal and carefully push the derailleur cage out to make sure it will move between the smallest and largest sprockets. If the derailleur range is too limited check the limit adjustments and look for anything jamming the parallelogram.
Reattach the shift cable and follow a guide for derailleur set up and adjustment. Park Tool has a good one.


Most bolts should have their tensile range marked on them somewhere, often stamped inside the hex cap. There should be a short number - 3.6, 8.8 etc.. Even a fastening rated as low as 3.6 is capable of 27 tons per square inch, more than 300n per square meter. A stainless steel M6 can probably handle 1.25 tonnes, the aluminium you're bolting into / through will fail before that.


Solved - I've bought new derailleur(claris ~20 eur) and I was able to configure it very easily. The problem in old one is really in broken inner plate geometry. This probably happend during my accident. Plate is bent in X axis towards towards the chain, which makes it really hard to bent back.


Do hardened chains cause more chainring and cassette wear?

There are two sides to this question, for the two places chains contact chainrings and cogs with force: the outer plates and the rollers.

There is probably a grain of truth to the statement in question regarding the hardness of outer plates. Sometimes you do see chainring ramping get worn to the point of not performing as well as a result of the rider, usually a racer, habitually shifting under load. Every once in a while you see it somewhat in advance of the teeth being worn. I don't see why this effect wouldn't be exacerbated the harder the outer links are. (That being said, I'm not sure which if any chains, expensive or not, have outer links that are any harder than other ones, since you don't really gain anything by it, and I'll bet the writer has no data on this either.)

For all the other parts of a chain - pin, roller, and inner link (or the bushing in the case of a traditional 5-piece chain) - you want it as hard as you can get it as long as the other mechanical properties (ductility being the big design counterbalance to hardness here I think) are what they need to be. That's how you get a chain that resists elongation the best and in turn keeps cogs and rings going longer, which is what most cyclists are interested in.

So basically the statement is misleading.


Replacing entire drivetrains on fixed gears is usually pretty straightforward. The main point of compatibility is making sure you're using a 3/32" compatible ring and cog if for some reason you use a 3/32 chain. In the more normal and advisable circumstance of using a 1/8 chain, it's hard to go wrong from a compatibility standpoint.

Unless there's something wrong with your cranks or you want something fancier, the normal thing to do would just be replace your chainring. If you are replacing your crank, you want any track-ish crank that's strikes your fancy, the nicer and more expensive (generally) the better for concentricity, plus a bottom bracket of it's manufacturer-prescribed spindle length, which will be spec'd to put the front chainline at the standard for track/fixed gear bikes, around 42mm. If you do decide just to replace your chainring, get anything of the right BCD and the tooth count you prefer that's made for singlespeed use. I've become extremely partial to the Surly stainless steel rings because they're well made, beautiful, strong, and economical for how long they last. If you're in the US, most of the house brand rings you'll encounter are totally fine too (Origin8, All-City, Dimension, etc.)

For the bottom bracket, if you stay with the existing cranks and presuming the chainline on the existing bike is good (the plane of the ring teeth and the plane of the cog teeth are within around 1mm), all you have to do is match your current spindle length.

Cogs are a place not to skimp ever. In the early days of the fixed gear revival and in the years before that, cheap stamped track cogs that are prone to stripping threads and in the worst case destroying hubs were fairly common. They're still out there, but a lot of us have been taught the hard way to steer clear, and thankfully the good options now outnumber the bad. Of the commonly seen good ones I would count Shimano, Surly, EAI, Origin8, and All-City (there are more but I'm speaking from what I've used/sold). I honestly don't think it matters too much which you pick once you're out of the junky price bracket, but I'm partial to the Shimano Dura-Ace cogs because of their increasingly rare confluence of exquisite precision and humble, utilitarian finish, plus they're quiet and last a long time. Lockrings are pretty much indefinitely re-usable.

For chain, the choice is basically use a basic, cheap, and functional singlespeed chain like the KMC 410, SRAM PC1, etc, a dedicated track chain, or a BMX chain if you want to get crazy. There is little to no downside in going basic. The other options have cachet value, and the nice track chains can be a little quieter perhaps.

It should be noted that some would answer your entire question from a perspective of what's quietest in each category, and that's not entirely wrong because it is an area where there are real differences in singlespeed drivetrain parts, particularly cogs.


How to get a broken torx bit out of a bleed screw?

From the photo you posted reasonable option is to drill a hole in the bit and use drill extractor, spinning it anti-clockwise.

Bit is made of hardened CrV steel, so drilling it may be hard, since it should be precise and centered. If you feel unsure about your skills, give it to professionals, to locksmith or to your local bike service. It may appear cheaper, since damaging caliper housing would be much more expensive than spending some extra euros to have it fixed.


Have a look at Sheldon Brown's handlebar reference. It lists typical clamp and outer bar diameters.

Unfortunately it does not contain oversized mountain bike handlebars, like your 31.8 mm riser bar. I suspect that the typical diameter for mountain bike bars at the handles at the grips is still 22.2 mm. You may see in the table that while the clamp diameter changed often, the outer diameter stayed constant at 22.2 mm and 23.8, respectively, for mountain bikes and road bikes.


Three possibilities that I see

You did not suddenly lose air you just did not notice until you got to the cobble stone
The rubber tube failed and recovered
The valve failed and recovered

No so sure you had a sudden loss of air.  If the tire when from 90 psi to 20 psi in a short period of most likely you would have heard that.

Since the valved is the only mechanical device I going with valve failed and recovered. Either random or by force of the cobble stone the valve unseated and before it lost all air it re-seated.

I am definitely ruling out rubber tube failed and recovered.

If this has happened to you before on that tube then I would replace the valve or tube and valve.  If this has happened to you on more than one tube/valve then wow - it has never happened to me.

I agree with the comment a patch could fail and then recover at a lower pressure but if you were able to air it back up and hold I would rule that out.  My mountain bike was down to 20 psi once and tube only at low pressure could not find a leak but with tire on at 50 psi it did leak (at a patch).

See picture below. The little gasket may have deformed or it has a little slit that is held together with compression.  Another possibility is the the valve itself (not the knob) is not screwed all the way in.  Where you see the flat spot on the the threads screw that in with pliers.  I had a set of tubes that by unscrewing the pump some times the valve would unscrew so I would use a dab of thread lock.  I think that is actually a picture of a presta valve that the core does not remove - so screwing that in would do no good.


What you do strongly depends on the road layout:

There is a dedicate bike lane
Stay on the bike lane and, if it also goes to the left where you want to go, follow it. Avoid cutting corners just to shorten your way and signal in time your intention (also other fellow cyclists prefer to know where you are going in advance). If the lane doesn't turn left where you would, follow next point.

You drive in the normal traffic
The normal procedure to turn left (assuming you ride on the right) is to get to the center of the lane and then turn as soon as no vehicles are coming from the front. Therefore put your left hand out in advance and make clear you want to move left. Wait some time with the hand out, check that no vehicles are approaching at your left and slowly but steadily move to the left. Complete the turn as soon as possible.

Alternatively, cross at a pedestrian crossing (dismounting from your bike if necessary).

In all cases:

Be visible: wear high visibility gears. Bikes are small and easily slip past consciousness in traffic.
Be assertive with your movements and don't zig zag. You don't want the drivers to assume you are just erratic in your cycling.
Listen and read the traffic. Learn to understand the context around you: are the drivers calm? Do you see anybody who is distracted or plainly a jerk?
Don't wear headphones or fiddle with your smartphone while cycling
Be fit and avoid cycling if you are not in condition of doing it. You want to be sure you can react promptly on the road
last but not least Safety first


Have you looked at the instructions for the derailleur? If not, it might help.

If the bike is a recent purchase, have you contacted BD? I'm not sure they will be able to help (how recent is a "recent purchase?"), but you have nothing to lose.

Your other alternative would be to go with the bike to a local bike shop, and let them repair it. It won't be free, in all likelihood, but you'll get results.


Could I use a 30 tooth chainring with my current crankset?

The key measurement for chainrings is the Bolt Circle Diameter (BCD). If you imagine those four bolts being points on the circumference of a circle, then the BCD is the circle's diameter. As always, Sheldon Brown's site is a good reference  here (and his crib sheet will help you work out your bike's BCD).

So having found out your BCD, any shainring with that BCD, and with the same number of bolts, should fit onto your existing crankset.

Now, you also need to consider how wide the chainring is. If you imagine the chain going around the chainring during cycling, what you're looking for is to have a perfect fit as the chain feeds into the teeth.

The problem is that there are two common chain widths out there: 1/8" (generally used by track bikes, some fixies, bmx, probably others) and 3/32" (generally, any bike with a derailleur, including road bikes and mtbs). So when you're looking to buy a chainring, it will generally be spec'd either 1/8 or 3/32 to denote the chain that it is paired with. Without getting too bogged down in detail, the best combination is where both chain and chainring are matched, although you'll get away with a mismatch, as long as the chain is wider than the ring.

Now, you say that your BCD is 104, and point to a chainring that might be a good fit. Certainly the BCD is a match. Also, while that url doesn't say explicitly 1/8 or 3/32, it does say that the ring is compatible with 9/10/11 speed drivetrains. In other words, with a geared bike. So you can deduce that it is a 3/32 ring, and should therefore fit with your current chain.

Lastly, note that if you are going to fewer T, you may need to shorten the chain.


Are Merrell Barefoot shoes suitable for bike touring?

I own a pair of these shoes, and while they are good for "barefoot" style running. I wouldn't want to bike with them except in an emergency. They are very flexible, with a thin sole that you can feel everything through. As such, I would say that they are definitely not fit for touring.


Are single chainring mountain bikes usual?

A 1x drivetrain (single chainring) is pretty much the standard now in mountain biking - you will notice the rear cassette is much wider than the classic 3x7 setup you are used to.  The wide rear cassette gives a wide range of gears (although not always as wide as the old 3x7). Most also have also moved to more speeds(sprockets) in the rear (i.e., 11-12 speed), if the 1x9 has a large range (which it appears that it does), it will have larger steps between gears than a 3x7 drivetrain you are used to.
Other changes in modern mountain bike drive trains are:

rear derailleurs are usually clutched to better retain the chain and control chain slap
a front single chain rings using narrow/wide tooth configuration to again better retain the chain

Better chain retention and a single rear derailleur means that riders have to think less about gears. In the modern setup you do not have to think about chain management, as the chains generally remain in the selected gear. Contrast this against a 3x7, where you often had to remember to shift Big-big (big ring, big cassette) before downhills to improve chain retention. This leaves the rider to focus more on navigating the terrain.
In terms of the pictured bike, the drawbacks relative to a 3x7 are likely a reduced range between the hardest and easiest gear and larger jumps between gears.

Update  - on road usage
The OP updated the question to note that the bike is intended for casual on road use.  The 1x setup is really tune  for trail usage were speeds are slower. Relative to the reference drive train (a 3x7), out of the box it will be less functional for on road use due to it being under-geared for the road (i.e., on the road you may find there is not a "hard" enough gear).  This can be alleviated by swapping out the front chain ring for a larger chain ring (as well as road friendly tires).  The gearing is more "tunable" than  reference drive train, where there were little option in the market  to change the 3x chainrings to different sizes.


Swapping out my front and rear derailleurs

Sora is a road groupset. Road front derailleurs are all bottom cable pull (I believe), your bike (and most mountain bikes) is top cable pull, so that is not going to be compatible.

I don't think swapping a derailleur within the Tourney range is going to make very much difference. You will probably get much more value out of having a bike repair shop adjust the derailleurs properly.

Currently the Shimano mountain groupset progression is Altus then Deore (between those two, Alivio and Altus were offered in the last few years as well).

Upgraded components will work better. You have to decide if it's worth it for you. Bear in mind that Altus and Deore are 9-speed groupsets so you'll be replacing derailleurs, shifters, cassette, chain, cable and housing at the very least. Your rear wheel hub may also have an older style 'freewheel' system rather than a 'freehub' system, if so you will not be able to upgrade.

Often, with bikes at the cheaper end of the spectrum, upgrading components is not worth the hassle, and just getting a better bike is the preferable option.


Hydraulic disk brakes vs hydraulic rim brakes

Some arguments in both directions:

Avoid disc brakes on a bike with quick release (QR) rather than through axles.
On the front loosening of QR by brake action may be a safety concern.
At both ends it is often difficult to position wheels with QR reliably enough to ensure there is no disc rub.
A QR equipped bike might be more convenient with rim brakes.
Six-bolt rotor bolts need to be tightened with exactly the same torque. One needs a small torque wrench or key for that. Uneven torque may lead to slightly warped discs and disc rub.
It is much easier to keep the brake surfaces of disc rotors clean than those of rims.
Riding in the wet may cause brake noise with disc brakes as well. Rain rides on lose surfaces usually kick up enough dirt to the rear disc to cause constant rub and noise.
Disc brakes allow much nicer rims. In particular carbon rims.
Magura rim brakes require mounting posts like cantilever brakes. There are no levers for drop bars. This rules then out for most road bikes. However, SRAM offers hydraulic rim brakes. *This is not correct, see comment by @stijn.
Don't restrict yourself to Magura when considering disc brakes. That they offer the best rim brakes and the best hydraulic system for rim brakes does not necessarily translate to disc brakes. For example, heat stability of their brake fluid might be an issue for discs while it does not matter for rim brakes.


How to alter a sports cycle to avoid wheel bend

If your rims are bending under normal loads there are a couple of things you should check and maintain:

Tire Pressure: Running at the higher range of pressure for your tires will help you avoid bending the rims when you hit holes or other obstacles.
Wider Tires: If your brake clearance supports it, you can run slightly wider tires. This will give you a smoother ride at the higher pressures you are running in (1).
True the Wheel, Tension the Spokes: Have the wheels professionally trued and the spoke tension equalized. When the wheel is out of true and the spoke tension has marked differences, you are far more likely to break spokes and bend the rims.

You should not have to switch to a different size rim, and doing so may not work with your brakes anyway. Riders for decades used 27" rims and if maintained well, do so with few problems. Note however, that if your current rims are in bad shape, they may not be able to be trued, and in that case, new wheels of the same size are recommended.

If you are riding on bumpy roads a lot, learn to true and tension the wheel yourself to save money. Constantly riding cobbles or bad roads may require you to true the wheels every few days or weeks.


This answer depends heavily on Shimano documentation and has a number of links to the Shimano website, which will inevitably suffer from rot. My apologies to all those reading this years from now when Shimano has changed all the URLs.

I think that in general the last couple of digits in Shimano component names/codes denote variations in the spec or quality level of the components.

One can dig around in Shimano's tech documents looking for answers. Current URL is http://si.shimano.com/#/

The Line Up Chart offers some insight into the compatibility of current parts (note there is an archive also).

The Nexus Inter 8 Chart indicates that the SG-C6001-8R hub can be used with the SL-S503 lever.

I note that the the 8R postfix in the hub name denotes 'roller brake spec', but I'm not sure if that means it has a roller brake built in or it is compatible with a roller brake. There seems to be a specific compatibility with brake levers for roller brakes.

Update: after reading the Sheldon Brown / Harris Cyclery page on roller brakes, I found out that the 'R' postfix hubs are compatible with an add on brake unit.


What Size Screw Holds the Up and Down Shifting Levers on Ultegra Shifter?

Surest way: Measure the screw on the other shifter and get a replacement at any place which sells screws. Use screw glue if you already know the screw comes loose easily.


Remove the valve cap
With the lever folded flat against the pump insert the valve into the Schrader port of the pump
Lift the lever so it is perpendicular to the pump body this will lock the pump and valve together
Pump the pump until the tire feels firm
Fold the lever against the pump body and quickly remove the pump from the valve
Measure the pressure with a tire pressure gauge
If the pressure is less than desired repeat steps 2 thru 5
If the pressure is above the desired pressure release some air and recheck it with the gauge
As a side note the more you use the pump the closer you will be able to judge the pressure by the effort required to push the pump


Best bike for neck in straight position?

A lot of recumbents, including the Cruzbike Sofrider pictured below, allow you to ride in the same kind of seated position you do in an office chair, and the ones that have high bars (instead of having the handle bars under the seat) allow you to mount rear view mirrors so that you needn't turn your neck to look backwards.
Recumbents are lower to the ground than upright bikes, which makes them a fast efficient alternative to "comfort bikes", though it also makes them harder to use than a road bike for fast city riding in dense traffic since you can't stand up to see over cars.

which are the best for:

flat area
hilly area

Recumbents are great for riding in flat areas, though not as good for hilly areas -- they're not quite as stable at low speeds since you can't as easily reposition your hips, and you can't stand up to torque when you run out of gears.

mountain bike, european city bike, touring bicycle ,recumbent bicycle

Mountain bikes can be ridden with back and neck straight but they're designed for people who ride with a slight forward tilt, and they're not efficient on roads.
Many European city bikes are similar to US Comfort bikes, and others like Dutch cargo bikes are designed with carrying capacity in mind.  They're good for riding wearing everyday clothes at a pace that isn't going to get you all sweaty, but are no good for recreational riding with people on faster bikes.
Touring bikes cannot as they have similar geometry to road/cross bikes.
As explained above, recumbents come in vastly different geometries, but many do allow the kind of riding posture you describe.


How differently will two bikes handle that have 1 degree difference in their head tube angle?

There is far more to the stability of a bike than just fork rake and head tube angles. I have designed bikes for a couple of years and the number of parameters is sometimes beyond believe. I have seen research that proved that a bike with a 90 degree head tube angle will stay upright by itself. Aha, you will say than it will be the centrifugal power from the wheels! Nope, the bike had two small skate wheels stacked on top of each other, so no influence there. It turned out that for this bike 'simply' altering the balance by shifting a weight made it stable :

             or look for Two Mass Skate Bicycle on Google.

So to answer your question : you will not notice the difference in the headtube. What you will notice is the overall difference in handling between the two bikes coming from the sum of all components in the frame design. So go and test them to make sure you get the one that fits you best.


What's the name of the tool to bevel bar ends?

When the tubing is cut the cutting tool leaves a ridge in the inside of the tube. A reamer removes this rough edge or burr. It is hard to say if your mechanic used a bicycle specific reamer which may be part of a bearing facing tool or a generic deburring tool.


I don't know what kind of bike this is. I need the name of this frame before I trade somebody

Its a BMX - but couldn't give a specific brand.

The front or back wheel appears to be a different colour and at least one of them has been replaced.

In addition the tread pattern on the tyres is different, so one of them may be newer than the other.

The gearing looks very small - both the chainring and rear cog look quite small, but that might be partially the white-painted chain.

Also the rear brake is interesting - it appears to be a U brake or a centerpull brake.  There doesn't appear to be a front brake at all, so it may not be road legal (depends where in the world you live.)

The front reflector looks like an afterthought, and the rear one is mostly obscured by the saddle and the rider.  However their presence suggests its for road use.

So it looks like a relatively modern BMX bike intended for road use, but its not a stunts or trials bike.


Full-face helmet/downhill context and short sightedness

I've considered using some road-style wrap-around cycling glasses with inserts.  My goal was to reduce the eye-drying effect of a downhill or a cold ride.

The frames on the inside clip into the housing, so can't be worn separately because they have no temples.  If you take these riding glasses off you'll need a normal pair to wear or go without.

The front part should be a polycarbonate, so the same plastic as a workshop safety goggle.  Some have a set of interchangeable fronts for different colours, which may be useful or may be for show (colour coordination).

You would need to get an optometrist to commission lenses that fit the inner frame.  This is just like getting a new prescription for a new frame, and most optometrists would be happy with that however some get snitty if they didn't provide the frame as well, so you may have to shop around.   You should be able to get a print of your prescription details from your optometrist then take that elsewhere for a lens quote.

I've not done this myself yet - my present solution is to wear normal glasses and squint a bit more when the wind gets cold.  This wouldn't be a good solution for you.


Super Heavyweight Biker keeps destroying Dutch bikes

My experience is with load bikes rather than people who are loads, but the principle is the same. A tandem rated wheel is your best bet, and possibly a heavier frame. Unfortunately most Dutch bikes are built for tall Dutch people who are generally not that heavy. 370 pounds is about 170kg, which is heavy. Pacific Island rugby player heavy.

What I would do is another custom wheel for your current bike, but with everything focussed on the weight. You can get hubs that are rated to a lot of weight, and Rohloff for example rate their hubs for tandem use even with only 32 spokes. But you should try for more spokes, I think, like the DT Swiss 540 Tandem with 36 or 40 spokes, or if your bike will take it the Halo Dozen with 12mm axle. Pair that with a heavy eyeletted rim like the Velocity Chukker or Mavic 719 and get it put together by someone who builds a lot of wheels.

Getting a custom wheel built with exact components can be mildly annoying, and not necessarily cheaper or better than finding a decent bike shop and letting them recommend something for you. That way you get their warranty. I suggest a load bike shop like Practical Cycles (found via google, I've never been there or to any part of the UK). If you do that and they get it wrong, it's on them to fix it. The magic words are

  fit for purpose  The goods should be fit for the purpose they are
  supplied for, as well as any specific purpose you made known to the
  retailer before you agreed to buy the goods.

(italics mine) Which incidentally means you should be able to get a complete refund for your current wheel if they can't fix it.

When we had this problem with a customer at the bike shop I worked at we first re-tensioned their existing wheel, but it broke more spokes the same day he got the bike back. Luckily he came back, because we were at least the third bike shop he'd been to, and even though I said "look, this probably won't work but I think it's worth trying" I wouldn't have been surprised to have him disappear. So we put together the heaviest duty rear wheel we could find, a downhill MTB hub we had in the shop with a 36 hole Chukker and somewhat oversize spokes (3mm straight gauge instead of butted just so it looked stronger). When I built it I took extra time to get it exactly right, and ran over it again after a test ride. He rang a few months later to say he hadn't had any more problems and just wanted to tell us.

(editing in some comments)

My feeling is that you can spend a lot of time and money trying to avoid just paying for something that will work.

The derailleur wheel is dished it's not as strong, as Rohloff discuss here and this Rohloff fan page might help :).

Use a 26" wheel in whatever frame you have as you will be using disk brakes so it's easy. A slightly smaller wheel is slightly stronger. Also, look closely at the rear wheel of this thing. That's a 9 speed 20"/406 wheel with 36 spokes that I threw together the night before I left on that ride. Normally it had four large panniers plus stuff on the rack, but a band is more interesting to look at. It was still going strong several years later when it was stolen. Smaller wheels make everything easier. If I could suggest a 406 wheel bike for you I would


What causes the different types of tire skidding noises?

The screeching that you describe is unlikely to be caused by the tyre skidding. It's more likely to be the contact between the brake pad and the braking surface causing the sound.

On an alloy-wheeled rim-brake setup, this is the rubber pad rubbing on the rim. If it's squealing, then it could mean that the surface of the pads has picked up some shards of the brake track and is scraping them on the brake track.

On a carbon-wheeled rim-brake setup, this could just be the standard sound. Some carbon wheels are just loud under braking and there's nothing to be done.

On a disc-brake setup, this could indicate that the pads are contaminated, requiring replacement. If the pads are sintered, then like the carbon wheels with rim-brakes, there's only so much you can do. Sintered pads are just known to be a bit noisier.

In any of these types, worn-out brake pads can also cause a screeching sound. If this is the cause, then you just need to replace the brake pads.


How to brake without falling during wet weather?

when I pressed the rear brake lever, the wheel stopped turning immediately, despite the slight pressure

if it locked up with only slight pressure, either your brakes lack modulation, or it had really poor traction.

The first (modulation) is generally adjustable.

The second depends on your tyres, the road surface, possibly oil/petrol/diesel spills, loose material etc. etc.

Since you don't think there was loose material, and say the traction was fine previously, an oil spill is certainly possible - look out for those rainbows on the road surface.

  Worse, the bike didn't stop, it started to accelerate

If the back wheel is locked, skidding it should still have some braking effect, so I'm inclined to view this as evidence for poor traction.

  I assume lowering the saddle would've necessitated much more effort from the front brake to throw me

Did you go over the handlebars, or just lose grip with the front wheel and crash?

If the former, which I think is what you're suggesting - lower saddle might help on steep downhills, but generally you need to brace yourself down & backwards with your arms. The goal is to stop yourself sliding forward relative to the bike as it slows down, and also to reduce the angular moment about the front axle by keeping your weight low.

Interestingly, this does suggest there was no traction problem with your front wheel, so something happened to impair traction at the back only.

  My bike is suited for XC racing

Does that mean it has knobbly tyres? More contact area is generally better on asphalt, so slick or textured tyres will have better traction (and, as a bonus, generally lower rolling resistance).

  Should I have kept the rear or both brakes engaged constantly

I'd usually drag the back brake to control speed on descents - to avoid overheating, don't do this continuously, but pump it and ease off to let it cool. Alternating with the front will also give the back brake a chance to cool - but note the front brake affects steering more, so definitely keep braking to the straights as much as possible.


How should I train for a century while still commuting by bike to work?

Take a "short cut".  I commonly take a "short cut" on my 10-mile commute, riding up to a neighboring community and then down a bike trail, adding another 17 miles.

Added: The advantage to this is that you're already dressed and on your bike, so the time required will be ONLY the additional time you actually spend on your bike.  Get going 90 minutes earlier in the morning or get home 90 minutes later in the PM -- no extra changing, no extra showers, no extra hauling the bike around.


Do clipless pedals that can have toeclips exist?

There are pedals that have a cleat clip on one side and a traditional platform pedal on the other side. You could attach the clip to the platform side and use the cleat side when you're riding with cycling shoes.

You might have problems when you're clipped in because the toe clip might hang too low and catch the road when you're leaning into corners.


Why is the swingarm design uncommon / rare on full suspension bicycles?

This swing arm design has fallen into near complete disuse in the bicycle world for 2 reasons:

First, there is translated suspension activation from pedaling. This design does not isolate pedaling or other rider generated forces from ground generated forces. Because of that, there is a loss of efficiency which makes it a poor choice for a bicycle suspension design.
Second, the travel path of a single pivot swing arm carries the wheel forward as it moves through its travel path, because of the arc described by the wheel. If your rear brake is in use, the wheel is prevented from following that arc, and some or all of your suspension travel is lost until the brake is released. In a 4 bar linkage design, or similar vertical travel design, brake activation does not prevent suspension activation. Thus it has become the default design for high quality dual suspension bikes.


The 8i uses what Shimano calls a cassette joint. It's wraps the cable around the back side of the hub and as the shifter pulls the cable it moves a bracket counterclockwise backwards on the hub body. Cable tension on a brand new Nexus/Alfine 8-speed hub needs to be precise.

Do this:

Shift the bike into 4th gear
Find the cable tension indicator. There is one on the top and the bottom of the hub. The top one is a small plastic window. The bottom one is a small piece of metal painted yellow. It may be easier to find if you can flip the bike over
Turn the barrel adjuster on the shifter until you see the outboard yellow line move
Keep turning the adjuster in either direction (probably out, counterclockwise) until the yellow lines are aligned
shift into 3rd gear, then back into 4th and adjust again
shift into 5 gear, then back into 4th and adjust again
repeat until you're satisfied with adjustment.

This should stop your gear slippage. If the shifter cable isn't properly lubricated or there's binding somewhere then you should see a problem while dialing in the adjustment. If you can't get this adjustment right to your satisfaction take the bike back and have the shop do it. They shouldn't charge you for this if the bike is new. Make sure they test ride it so they can experience the problem.

If this is an old hub and you've ridden it misadjusted for a long time it is possible to damage the hubs innards. Replacing the hub guts should only be done at a shop that deals with these hubs regularly and has the special lubricating bath that they require for proper maintenance.


What are the current options for short crank arms?

There aren't many options out there for cranks shorter than 165mm. Your best bet is to buy a set of longer crankarms and get them shortened at a service like Bikesmith Design.

Also, if you are legitimately having knee problems, I'd suggest that you find a professional fit service in your area and have a fitting done. The length of your cranks may not be the issue, but it may be the size of your frame, position of seat, etc. Online calculators can be good, but a professional service will certainly address these issues in a more targeted way and perhaps save you from spending unnecessary money, modifications to parts and perhaps save you a lifetime of pain or discomfort.


Maximum down position is odd - that's when the power stroke is over so its not the pressure causing your noise.  Did you assemble it yourself?  Could be a loose pedal, or a pedal bearing needing lube.

Try popping the chain off the chainwheel and pretend to pedal.  See if the noise still exists.  If yes then its not your chain.

Finally - since your bike is new, have you taken it back to the shop for a tune up?  Almost all bike shops offer a tune after 6-12 weeks to fix up cable stretch issues etc.  A minor creak like this should be covered by that, or by warrranty.


spoke end poking out of rim, thinking it may be reason why Im getting flats

If you can see the end of spoke going out of the nipple, you should polish it with a rasp. If you do not see it, but feel with your hand, the tape will be enough (if it put right, as Batman wrote).


Is conserving energy something to do on a day-to-day basis, or over the week?

All other things being equal and provided the commute is no more than an hour you should be able to recover in full for the next day.

I reckon that with decent food and rest you will always recover in time.

That said if the week is long and tiring and you don't get enough rest you may be slower on the Friday than on the Monday.


At some point the spokes become too fatigued and start snapping.

At some point, with rim brakes, the rim wears through until it's no longer stable.

At some point the bearing races in the hub become too worn.

Of these, only the third reasonably demands that the wheel be replaced -- wheels with worn spokes can be relaced, and rims can be replaced without relacing.  But in some cases, especially if more than one of the above problems is looming, it may be more cost-effective to replace the wheel rather than repair it.

And, of course, there's always the case of some sort of actual damage to the wheel -- ripped spoke holes in the flange, bent flange, "taco-ed" wheel where both spokes and rim will need replacing, etc.


Winter tires with removed studs as summer tires?

While the tire itself might or might not be intact after removing the studs, the tube inside the tire would suffer. Studs are installed by piercing the tire itself, and you'd have to patch the hole left by each stud or you'd have blowouts.

I suggest selling the extra studded tires.


The frame seems suspicious: it clearly was TIG-welded, just look at those smooth tube joints and compare to 80s lugged frames, which means the MY should be at least in mid 90s. The Dyna looks very similar, but the the dropouts don't match (holes vs no holes). Newer frames either have seatpost bolt inline with top tube or a modern collar, but the frame in question has the bolt at least a centimeter higher than the top of the top tube. The paint doesn't match the time period either, the most similar paint jobs date to 80s lugged frames, just like the head badge. I think it was repainted with the use of an aftermarket decals set.

I'd look for any branding cues in every crook and nanny and ask the previous owner about the model and paint job.


MTB Cassettes- are they universal to wheels

There are currently 4 MTB freehub/cassette standards for SRAM/Shimano drive trains:

7 speed - Shimano/SRAM - based on Shimano HG
8/9/10 speed - Shimano/SRAM (a 7 speed cassette with a 4.5mm spacer also fits) based on Shimano HG
Shimano 11 speed - fits an 8/9/10 freehub (MTB only) - based on Shimano HG
SRAM 11 speed - XD driver freehub - SRAM proprietary system

Campagnolo has two spline patterns also, 8 speed and 9/10 speed.

Unless you a running a SRAM 1x drivetrain it's generally safe to say cassettes will be compatible for the same number of gears.


Are MIPS helmets actually any safer than standard helmets? Independent Research?

Summary

Research into brain injuries has been ongoing, but tended to focus more on direct impacts. In the last 70 years there has been more research into rotational brain injuries, and in the 1990s and 2000s scientific, evidence based proposals were made to reduce these. The Multi-Directional Impact Protection System is an implementation of these, and it's effectiveness has been validated by independent research.

Discussion

There is lots of research into brain injury. While much of it has focused on direct impact leading to scull fracture, the effects of sudden head rotation have been studied since the 1940s. These (pay-walled papers) are typical

A study on rotational brain injury (1984).
Physical model simulations of brain injury in the primate (1990).

Such studies progressed to proposals, such as

A proposed tolerance criterion for diffuse axonal injury in man (1992).
KINEMATIC ROTATIONAL BRAIN INJURY CRITERION (BRIC) (2011).

  [In] 2008 ... Swedish neurosurgeon Hans Von Holst, along with mechanical engineer Peter Halldin, developed a new technology called MIPS (Multi-Directional Impact Protection System).

A couple of (non independent) articles are

New Helmet Technology Reduces Brain Injury
MIPS

Mips has been received with acclaim

Precious Protection (2010).
Senseless: An In-Depth Look at the State of Bicycling Helmet Technology (2014).

There has been at least one study of their effectiveness

Angular Impact Mitigation system for bicycle helmets to reduce head acceleration and risk of traumatic brain injury. (2013).
This found a 34% reduction in peak angular acceleration and predicts that AIM helmets reduced the risk of concussion [by] 44%.

But not everyone is convinced regarding helmet effectiveness. For a helmet skeptic's view see

Cycle helmets and rotational injuries.
The views expressed here are out of date, but it's the only skeptical view I found regarding rotational brain injuries.

Certainly, more independent validation would be good, and in future better designs could appear. At present MIPS seems to set the brain protection benchmark.


Upgrading a entry level hybrid bike or purchasing a new better one

Upgrading an existing bike piecemeal is always going to be more expensive than buying a new bike with the specs you want, because manufacturers get components at a discount.
Regarding Option 1, upgraded components will not transmit more stress to the frame, if that's what you're asking. It is possible (but seems unlikely) that the frame was engineered with just enough safety margin to allow for light trail riding, but not more intense off-road riding. I wouldn't let that guide my decision.
The gravel-bike category is a broad one, and some bikes are more road-ish, others are more MTB-ish.
If you frequently cover both tarmac and dirt in a single ride, that sounds like a good argument for a gravel bike. Everything is a compromise, and you need to figure out what compromise you're most comfortable with.


Shimano shifter neither reaching top nor bottom gear

Common reasons for a derailleur not getting to the low gears (larger sprockets) is the shift cable slipping through the pinch bolt that secures it on the derailleur, cable housing has come out of shifters or frame stops or bad adjustment via the barrel adjusters.
The common reason for a derailleur not getting to the high gears (smaller sprockets) is the cable hanging up in the cable housing and preventing the derailleur spring from moving the cage outwards.
First follow the cable run from the shifter to the check the cable housing is properly inserted in the shifter and all frame stops.
Detach the cable from the derailleur, tension the cable by pulling on it with a pair of pliers, work the shifter and make sure it shifts through all gears and pulls in and lest out the cable smoothly. If the cable does not move through the housing smoothly take the cable out and wipe it off, if you still have problems replace the cable and housing.
With the back wheel of the ground, manually pedal and carefully push the derailleur cage in to make sure it will move between the smallest and largest sprockets. If the derailleur range is too limited check the limit adjustments and look for anything jamming the parallelogram.
Reattach the shift cable and follow a guide for derailleur set up and adjustment. Park Tool has a really good one.
Cleaning the chain, derailleur jockey wheels and sprockets and re-lubing the chain will help also.


Help with setting up Windsor Kensington bike on CycleOps Mag+ trainer

I have a cyclOps trainer.... The way the attachment works is pretty cool and does not require a quick release.  Essentially, each side of the attachment point is a slotted tube that fits around the axel  (the slots are to make room for quick-release scewers) the non-drive side slotted tube can be threaded in and out to get the tension right for your bike width.  The drive side has a lever that pushes the drive-side slotted tube in and then locks into place  (the bike is secured by clamping using the lever and the non-driveside adjustment).

It is pretty universal, you will place you bike on the trainer, adjust the mag (another handled adjustment) such that when the rear wheel sits on it your non-driveside axle lines up with the non-driveside slotted tube on the trainer...  to tighten the bike-to-the-trainer pull/rotate the lever on the drive side of the trainer.

The first time performing the process will be iterative to ensure you get the adjustments just right so the bicycle is secured to the trainer.  Once done it will be good to go.  To remove the bike just release the trainer driveside lever... to put the bike back on the trainer just line it up and re-engage the lever.


Stripped threading on upper rear rack bracket

A few ideas:

Buy a seatpost-mounted rack (this would be a good solution for the long term if you want to keep taking your rack on and off, but check the weight limits).
If you're going to keep doing this, when you've solved the immediate problem, put some stainless studs in the holes with threadlocker and use a nut on the outside. You should probably use a dome (acorn) nut to avoid hard edges.
If there's a rubbish thread but just enough to get a bite, degrease the hole, cover the first few turns of a stud in epoxy and screw it in. Leave overnight before fitting the rack.
P-clips onto the seat/chain stays can replace the mounting bosses for all but the heaviest racks.
You could probably tap it out. I'm used to M5 rack mounts so you'd need to go to M6. I'll the hole out with a 5mm drill then use an M6 tap. You'll probably need to start with a taper tap then change to a bottoming tap. You'll also need to open the hole on the rack to a little over 6mm (if you can't get a 6.2mm drill, use 1/4"). I reckon a metric tap set is worth having, but be sure to get one with pilot drills as these are otherwise uncommon sizes.

On my bikes I'd go for (1) P-clips (or tap if high loads and plenty of material); (2) tap it out (3) seatpost rack; (4) epoxy and only on my old bike.  But I already have all the tools/materials for all these options.

All links are examples rather than recommendations.

It should probably go without saying but if you've got a child seat mounted on the rack, you should probably forget about the repair, or using the rack in its current state. But you can get a seat that fits to the seat post.


I would say yes, use copper grease / ti prep / anti-seize on any titanium-to-metal contact (and especially ti to aluminum) that you anticipate staying put for a long period of time.

Length of the seatpost - yes
Seat post clamp - yes
Bottle cages bolts - yes
Rear derailleur - yes

The front derailleur clamp seems more questionable because it isn't threaded or a tight fit in theory, but sure, why not? Applying liberally is better— you want the copper grease to stay put through washes and rain to do its job.


Why do I always get punctures in my rear wheel?

The back wheel is the wheel bearing most of the weight and also the wheel providing the driving force. For these 2 reasons it is likely that the forces being exerted between the wheel and surface are much greater on the rear wheel than on the front. This makes it more likely that you will get punctures on the rear wheel than the front - all other things equal.


How can I run a dynamo wire from my front hub to my dynamo light?

I was finally able to do this by taping the end of the wire so it extends about 1/2" past the end of a bent-straight coat hanger. Using this, I was able to get the tip of the wire near the bottom vent hole, and wiggle it around enough that I could locate the wire ends. Then it was a bit of work to catch the wire and pull it through with fine needle-nose pliers, but I was able to get it twice within a minute or so after burning nearly an hour trying to fish it through using other methods.


Cycling is cheaper than walking.

I asked a few people what they think is cheaper, walking or cycling, and everyone answered that walking is cheaper. It seems logical, because to walk, all you need is shoes, while to cycle, you still need shoes, but you also need a bike and arguably a helmet and gloves.

There's a wide range of prices for both shoes and bikes, and it's up to everyone to decide how much they want to spend on each, but to make this a fair comparison I will use lower midrange UK prices in my calculation.

One pair of shoes is obviously cheaper than a pair of shoes, a bike, a helmet and a pair of gloves, so if you are comparing the cost of going 10 miles, walking is definitely cheaper:

However, at 10,000 miles, the numbers look very different:

The cost of walking 10,000 miles is 20 times higher, while the cost of cycling didn't even double. Already after 10,000 miles, the bike has payed for itself and is saving you money, even compared to walking.

I know that there are other components that you will need to replace, such as brake pads and cables, but these could last 10,000 miles depending on your riding conditions, and even if they don't, they are so cheap that they will barely make a difference to final cost. I also didn't include the cost of labour and the tools needed to perform the maintenance. Most maintenance tasks are easy enough that you can perform them yourself and the tools needed are generally pretty cheap. Again, it wouldn't make much difference to the final cost.

Now, there are a few things that would make a huge difference to the calculation. If you put a price on the time spent traveling, cycling is several times more cost efficient than walking. However, over short distances, you might find yourself spending all the time you saved, by going faster, on parking and locking your bike. Theft and accidents, can completely ruin the numbers for cycling, but you can also get mugged or have an accident, while walking, so it's not completely one sided. I left these things out, because they are too situational and hard to predict.

Cycling is also more energy efficient, but I don't think most people would notice any difference in their food consumption, so I don't think it's worth trying to estimate how much money that would save.

I think my calculation is fair and even if my estimates are a bit off, I think it's quite clear that, given a long enough distance, cycling is cheaper than walking. Any feedback is welcome and I really don't mind to be proven wrong.


Best bet with quick releases when they are hard to remove because of the frame in the way is to get a rag, place it against the frame and then use a long-handled screwdriver to pry it up. That works all the time in the bike-shop I work at. Good luck!

EDIT

I should actually say, if you have carbon fiber release levers, be VERY careful not to crack/crush it, otherwise that's gonna have to meet the wheelie bin.


Sorry to say that you can't if you want to stay with SRAM.

Looking at the list of SRAM cranksets:

Mountain: https://www.sram.com/sram/mountain/component/cranksets
Road: https://www.sram.com/sram/road/component/cranksets

There are none that have 11sp and 3 chainrings.

But looking at the spec of the bike that I think you have:
http://www.halfords.com/cycling/bikes/mountain-bikes/carrera-fury-mountain-bike-2015

It appears that it's 2x10, rather than 2x11 (it says 20 gears "SRAM X5 20 speed").  Can you check if it's really 11sp that you need?

If you need 3x10, then you'll need to change the crankset and the left shifter - and possibly the front derailleur - though you can probably get away without it.

You can find a matching X5 SRAM 3x10 crankset online pretty easily e.g. http://www.ebay.com/itm/SRAM-X5-GXP-175-10-Speed-44-33-22-Crankset-/272056712049

Note that going to 3x10 does not give you easier gears.  It just gives you smaller jumps between gears.  If you want easier gears, then there is a much simpler and cheaper solution: get a smaller small chainring, and/or a cassette with a larger big cog.


How can I tell what frame model/year this bicycle is?

Bikepedia is a good resource for indentifying models, year and spec levels.


What you most likely have is an old-fashioned coaster brake, along with a hand brake.  In reality the coaster brake is probably more "natural" for someone learning -- the hand brake is mostly an affectation designed to make the bike appeal more to boys (of all ages).

But it is possible to disassemble the rear hub and disable the brake in most cases.  There are 3-4 different mechanisms used, so it's impossible to give you detailed instructions, but it would be apparent to anyone with sufficient mechanical aptitude.  (But note that the rear hub, in addition to being very greasy inside, contains lots of little parts, and reassembly requires some skill.)


14G and 2mm are synonymous concerning the spoke thread. It should just fit.
The flats should have a distance of 3.23mm.

https://en.m.wikipedia.org/wiki/Spoke_wrench


Most of these older design entry level fork have no serviceable parts the best you can do is disassembly it and cover all the moving parts in grease. On most this requires removal of the little plastic caps on the top. If you shine a flashlight in you will likely see a 5mm allen screw. To remove the screw you need a "LONG" allen wrench. Alternatively you can purchase a 3/8" drive 5mm socket and use a 3/8" drive socket extension to remove the screws. Count the number of turn it takes to remove the screw so they can be reinstalled in the same position.  Once the screws are removed the lowers will slide off. Clean everything on the lower inside and upper outsides. Examine the upper legs for rust and if necessary sand smooth and spray with epoxy paint. Cover everything with grease (I use white lithium) and reassemble. After all of this you may notice  little if any difference. Most of the forks I have seen on kids bikes are so stiff that children don't weigh enough to compress the fork anyway.


Bailing out with SPD pedals on a mountain bike

Your best option is to practice a lot on how to unclip your foot, so you get accustomed to it. I suppose you have already done this. So you must now adjust the spring tension on your pedals. Refer to the instruction manual on how to adjust it.

Aside from that, I have found that dirt, grime and other pollution in the cleats makes it extra hard to get the foot free. It gets to your pedals every time you step on mud or soft soil and then go back to he pedal, something that does not happen so frequently for a road biker.

When you cleat after stepping on mud or soft soil your shoe picks up little stones, little stems, leaves and all sort of things that clog up the pedal's mechanism, and the pedaling action makes all this dirt get to critical places.

That's why I recommend to thoroughly clean the pedals and oiling them between rides. Normally you won't get too much dirt in only one ride, but you don't want it to get accumulated, for this worsens the performance of the release mechanism. Oil helps a lot for clipping in and out, but also helps a little by not allowing some dirt to stick to the mechanism (Your pedal won't be so dirty by the end of the ride).

Tip #2: you should periodically inspect your pedals and cleats for dents, deformations and other that can affect your ability to clip out. Specifically I've had trouble with the "ramps" that push the cleat out when you twist your foot. For some reason these develop a kind of hook that prevents the foot from twisting. You can easily file out these deformations, usually they are surprisingly tiny! Use a fine file or a rotary tool (dremel) with a fine grit grinding stone.

Tip #3: Part of some training I also did, was about conquering difficult technical sections without removing any foot from its pedal. I did this by  building small obstacles in the middle of an ample flat terrain. The Obstacles where made of stones and logs, trying to make then with increased difficulty every time, but always made then in such a way that if I fell it wouldn't hurt much, hence the flat clean terrain around the obstacle. This kind of training gives the rider a lot of self confidence and builds the necessary skills that make the use of cleated pedals more intuitive at the required level for MTB riding.

These tips have kept me clipped for 10 years of mountain biking, doing XC, and a little all-mountain and downhill.

My final comment: IF you're accustomed to SPD on your road bike, make an effort to stay on SPD for your mountain bike, if you remove them, almost sure you'll miss them!


Schwinn closed the Chicago plant in 1983 shortly after opening a plant in Greenville MS. They were also importing many bikes at that time. Your '85 Traveler was built in Greenville MS. The headbadge still read "Chicago" because Schwinn's corporate offices remained there.

The serial number SC5xxxxx indicates the frame was built in March (C) of '85 (5), and the 1025 headbadge number indicates the bike was built on the 102nd day of '85, or Friday April 12th, 1985: http://www-air.larc.nasa.gov/cgi-bin/jday?month=3&day=11&year=1985&Show_Calendar=Show_Calendar

This of course means your bike is an '85 model as depicted in the catalog here: http://bikecatalogs.org/SCHWINN/1985/LightWeight/Traveler.html


Campagnolo drivetrain compatibility and noise

I ended up taking my bike to Dickie at Waverley Cycles. I had a couple of problems:

The chain was too long (I hadn't removed enough links)
The cable adjuster on the derailleur had stripped threads so had movement

He shortened the chain, screwed the adjuster further in and used the adjusters on the cable stops near the front of the bike to tune it and everything is now silky smooth


Why are puncture-resistant tires not used in professional races?

To a racer, rolling resistance and handling top the list; durability is far down the list. The coefficient of rolling resistance (Crr) for a racing tire on typical French or Italian roads used during a Grand Tour is about .004, or even lower. The Crr of a puncture resistant tire can be > .01. Crr scales like gradient, so the difference between Crr's of .01 and .004 is like constantly climbing a slope of .006 (=.01 - .004), or slightly more than half a percent. On a 150km stage that's like climbing an extra 900m hill. No racer willingly gives up that much advantage, especially when there's wheel support from either a team car or neutral support (and for team leaders, a wheel swap from a team mate) should you get a flat.


Do I need to be concerned about a carbon frame if I attach a bike trailer?

I'm not sure of the type of bicycle you have, the trailer you're using, or how much you plan to tow. However, I have a BOB Yak that I tow behind a 2007 Specialized Allez Expert (with carbon fiber seat stays, but not chain stays), and I have not had any problems carrying groceries, textbooks, and other paraphernalia.

If your wife's bike has a similar setup (carbon seat stays but aluminum/steel elsewhere) it should be okay as long as you are careful about weighting the trailer and try to reduce the rotational forces (my trailer is single-wheeled, so it leans with the bike) by not standing in the saddle and rocking from side to side for hill climbs.

You're also right about the wheel taking most of the acceleration and braking forces, as well as weight. On that note, you may want to consider how beefy her rear wheel is, if she has a lightly spoked rear-wheel, you may want to consider a heavier wheel to avoid destroying a 'lighter' racing tire.


would you use vo2 max intervals increase your functional threshold power using a power meter?

Those should both be staple type workouts in your folder. There are basically two types of workouts that you should be doing to increase your speed, and both of them are described fairly well in your examples.

The first is a threshold workout - This is a pace that is at or near your race pace, with relatively short recovery. This is the second workout you describe, with the 80-85% FTP. (Remember that an FTP measurement is generally described as the maximum effort you can sustain for one hour). In this you are doing near a race pace, with short recovery compared to the length of the sustained effort. This type of effort is designed to increase the amount of time you can hold a high effort level.

The second is an interval workout, which is what your first workout describes. This is short periods of very intense effort, with enough recovery to ensure that you can complete the next interval at the desired level. If you note, the recovery period (3 minutes) for this one is nearly as long as the recovery for the threshold workout (4 mins) for a much shorter effort. This workout is designed to increase your top end speed.

Taken together over time, these workouts will increase your top speed, and increase the amount of time you can spend near that speed.

They are also somewhat dependent on the time of year. During the "off season" if you will, you should be concentrating on long distance riding, not much intensity, to get a good base for the next year. A couple of months out you should start adding in some of these workouts, and increase the frequency in which you do them through the first few months of the season, then change over to fine tuning and maintenance type workouts. If you are unsure of how to do that, a coach can be a huge help.

As far as measuring FTP, I'm not a big fan of the 5 minute tests. I prefer either an hour time trial if you can manage that, or the 2x20 method, preferably on the road.


Cyclocross courses are (generally) too smooth and relatively fast to warrant the use of suspension. Sure, it might be more comfortable, but the added weight would only slow you down and leave you behind  your competitors on a typical muddy course.


No.  That indent or wear groove is to indicate the amount of wear on the rim.  If you can no longer see the indent, it means the rim is worn and should be replaced.  Sheldon Brown's take.  It's similar to if you no longer had tread on a tire.  You couldn't re-indent the tire to make new tread.


Training plans are all well and good, but the first goal is to be able to ride 9 hrs.

There is no substitute for doing long rides to prepare to do a long ride. In my experience,
for just developing pure endurance you get 80-90% of your training effect from a long ride. The rest of your training should be focused around reducing the recovery time to enable you to do your next long ride. There are also lot's of logistics around eating and drinking for 9hrs on the bike that you'll have to figure out as well and there is simply no way to know what will work for you without getting some 5-6 hr rides as practice.

Given that you'll be inside the next 3 months, you should probably focus on consistency with some intensity work. Do as much cross training as you can. It's very hard mentally to do significant endurance training on trainer. If you can find another activity like XC skiing or a similar winter endurance sport, that would be beneficial. The most important part over the winter is to stay consistant and to not mentally burn out. You want to be raring to go when the weather gets good, not disgusted with riding due to burning out on the trainer. Going to the gym to work on flexibility and core strength is also a good winter activity. 9hr rides will make muscles painful that you normally don't notice riding.

Once the weather gets nice start working towards a regular extra long ride at least every 2 weeks, every week would be good if you recovering in that time. Start at 3 hrs and add a half hour until you start to reach a point where you can't recover in time for the next ride. Stay there for a while until you're ready to make the next increment. You'll know you're ready to move to the next level when you're excited to do a long ride, if it starts to feel like a job or an obligation, that's the time to step back.

Endurancing training is as much about managing recovery as it is actually training. People with the mindset to enjoy endurance sports rarely have trouble with training, but they almost all struggle with overtraining. Learning when to push through and when to back off takes a very long time. As a relative beginner, I'd urge you to err on the side of caution. Taking a rest week every now and then should be part of your plan. Taking a week off will not significantly affect your fitness at all and might provide suprising benefits. Overtraining that extra week can destroy months of training with injury and illness.

300 km in 9 hrs is a very ambitious goal. If you want to be confident I would want to be
doing training rides of at least 6 hrs, 7 or 8 hrs would be better.

You'll also need to taper at some point before the event. Plan on at least 2-3 weeks of reduced effort leading up to the race.


Can I change my derailleur without changing my shifter?

Yes.
All Shimano MTB groupsets up to 9 speed all used the same derailleur actuation ratio (how far the cage moves for a given cable pull), so all 8 speed MTB shifters are compatible with all 8 speed MTB derailleurs.


Cyclocross racing with fixed gear road bike with cross tires

Neither option is a good idea:
If you use caliper brakes for the cross race, they can easily be filled with mud and became useless.

If you go with fixie you'll be very slow on steep uphills and it will be dangerous to downhill without a freewheel.

But you can try if it will be very simple race :)