How do the adjustment barrels on a gear cable work?

Your basic barrel adjuster is a tube with a thread on the outside of one end.  The threaded end fits into a female threaded piece, either the shifter itself or another tube.  (If you have this second type, where the female end is another tube, it's necessary to hold that second tube stationary while turning the first tube.)

The cable passes through the tube, and the cable housing "bumps into" the end of the adjuster barrel (which generally has a sort of "cup" sized to accept the housing and keep it centered).

The adjuster works this way:  As you UNSCREW the adjuster, it pushes the cable housing farther out, effectively tightening the cable.  The cable is held in tension by the spring in the derailer, so this adjustment moves the position of the far end of the cable relative to the derailer.

[Note that some adjusters have a thin "jam nut" on the threaded portion of the barrel, and this is tightened against the female piece to keep the adjuster from turning.  It's often necessary to unscrew this jam nut slightly before working the adjuster.]

Note that once you've unscrewed the adjuster beyond the end of the threads it won't tighten the cable anymore, but will just spin.  If this occurs (before satisfactory adjustment is achieved) it's necessary to screw the adjuster all the way in, loosen the cable clamp at the derailer, and pull it a hair tighter.

Also, if some jackleg in the past decided to "tighten things" with a pair of pliers they may have broken off the threaded portion inside the female portion, rendering the adjuster completely ineffective.


How to adjust cleats to lower pain in the right foot's last two toes

I suffer from pain in my feet on long rides. I believe it's caused by lack of blood flow and pressure on parts of my foot. I currently have a new pair of shoes and it is definitely worse when using those. You will probably find the issue improves as your shoes get properly broken in.


What kind of maintenance does a shimano dynamo hub need?

The common Shimano Dynamo hubs don't actually use sealed cartridge bearings, see the DH-3N71 and DH-3D72 techdocs. Shimano dynohubs do use good seals, however, and should hopefully be maintenance-free for many thousands of miles.

Alistair Spence has a good exploded view of an Alfine DH-S500, which is very similar to the DH-3D71.  He also links there to a disassembly guide PDF, the original of which can be seen (minus images) in the internet archive.  The steps are basically the same as a standard front hub, with the caveat that it is important to be careful to avoid breaking the axle wire.


Why are brake levers still bent in form to accomodate more than one finger?

TL;DNR - single finger levers have little (if any) advanatage and some disadvantages.

Most people do not start out cycling with XT/Ultegra quality bikes and therefore (do not) start out on bikes that have brakes good enough for one finger control.  Even today, many low end disc brakes cannot reach full braking potential (i.e. wheel lock), with one finger. Also think of kids' bikes and kids' hand/finger strength.  No way an average child with an average child's bike can brake with one finger.

People transitioning from those brakes would likely be uncomfortable with single finger levers during the transition, and would likely not buy a bike equipped with them. If the bike might be resold or lent out, one with single finger levers would have a smaller potential market.

Poor maintenance, accepting pad contamination can occur at any time, means even the very best brakes may require more force than a single finger to achieve full stopping potential.

Presuming the bike has good, well maintained brakes and single finger braking is how the rider rides all the time, what's the disadvantage of current lever designs? They work very well on a single finger.  A rider can intuitively feel exactly where on the lever the finger is to achieve maximum performance. Changing the shape will not improve braking, and there is no weight saving to be made.

The only advantage would be aesthetics and marketing spin to sell the new shape as a premium product aimed at the cashed up MAMILs.


Fixie Vs Urban bike for small-distance commuting

For practical day to day commuting I would stay away from a fixie because:

You are not a very experienced cyclist, riding a fixie in traffic is actually not that easy.
No fenders, so dirty clothes/mud in the face on rainy days.
No rear-rack, so for luggage you are forced to use a backpack.

I also wouldn't go for the type of urban bike you link because:

You will have a very straigth posture on the bike. This makes quick steering more difficult even though it might be a matter of life or death in traffic.
The straight-up posture with your pedals almost directly in line with your torso is not very comfortable when you have to put some effort into your cycling.
The small wheels make this type of bike unnecessarily unstable.
A luggage rack on the handlebars leads to unpleasant/unresponsive handling.
It looks dorky (but that is just my opinion)).

I would find a nice secondhand bike that looks like the fixie you link but has fenders, a rear-rack and proper brakes.


I suggest borrowing a pump with a pressure gauge and pumping up your tyres with that. Then try your gauge once you know the tyre pressure. Bike shops and a lot of cyclists have a floor pump because they work better than the little portable pumps than most cyclists carry. And those have a gauge on them that's usually fairly accurate.

You say the pressure release button on the gauge "doesn't seem to make any difference". What do you mean - does the gauge drop back to zero? If not it's definitely busted.


Why might my inner tubes be getting consistently punctured?

So, I think the problem is that I have a 25mm tyre on a rim designed for narrower tyres. That means the rubber surrounding the valve is distorted into the narrow valley of the rim, which puts stress on it. As @Batman suggested, failure #2 seems to be a red herring.

So, I've opted for the narrowest tube available and furthermore used a cutting from an old tube to provide padding around the valve, like this, so that the rubber doesn't have to distort so much to reach the base of the rim valley.

It's still inflated so far, will mark this solved if it's still inflated at the end of the day!


What road double cranksets will work with a 108mm JIS square taper bottom bracket spindle?

Going off-spec here is only useful if your spindle is actually symmetric 108mm.  If it's older and asymmetric it may actually be equivalent to a wider modern bottom bracket.  You also don't specify a BCD preference; it looks like the cranks designed for narrower spindles seem to be 110mm BCD.

According to Harris Cyclery, the Origin-8 cranks give a chainline of 43.4mm with a 107mm bottom bracket, which would be only 0.4mm off the Shimano spec of 43.5mm if your spindle is symmetrically wider.

The Sugino XD Swiss Cross lists 45mm as the chainline with a 110mm spindle; that would be 43mm in your case and 0.5mm to the inside.  Possibly good if your frame can handle a narrower Q-factor.

The TruVativ Touro and other TruVativ square taper cranks also seem to be designed around a 108mm bottom bracket.


Are there rim brakes for road bikes compatible to Shimano hydraulic brake levers / brifters?

I would pick up a pair of cyclocross-style brakes levers that are designed to mount on the flat part of the bar and run inline with the brake cables. You can also mount them to the end of the bar and just have the cable terminate at the lever. The angle might not be quite right with the bullhorns, but some levers come with an adjustment screw that lets you set the default position of the lever. I would make sure to get some like that. And then you can just use whatever bar-end shifters you want.


Will a white painted bike get rusty when stored outside?

The problem with sealing it tight is that water will get in, even just as humid air, then it can't easily get out. You'll get condensation, which will cause rust.

It's much better to shelter the bike so that rain can't hit it or blow in easily, but leave the bottom open so that water than run out. A motorbike rain cover would be ideal, but a tarp thrown over with a rope looped around lower down to hold it in place will be fine. Try to cover the rear derailleur and the chain when doing this, as those are especially likely to rust.

Note that it's a really bad idea to spray the chain (or anything else) with a degreaser like WD40 before you do this. You're better off buying proper chain lube and over-lubricating the chain and derailleurs before storing the bike for any length of time. That excess will better protect them, and then when you pull it out of storage add a little more lube, spin the pedals backwards 10-20 turns, then wipe the excess off (that replaces any volatile parts of the lube that have evaporated while it was stored)


Waterproof overshoes: am I using them right?

I've got a couple of pairs, and have had similar experiences.
The best I can do is with my better pair (with a reasonably tight but comfortable ankle strap) underneath my splash - resistant leg warmers. That keeps out a short heavy shower, or light drizzle for a few hours, but persistent rain always gets in (and anyway feet get sweaty in overshoes). Short socks (well below the ankle band) help as they don't provide a part for water to wick.
They'll never seal well enough if your feet dip in a puddle, even if, like me in winter, you tape up any vents in your soles. Even splashing from underneath can get in eventually.
The overshoes are still very beneficial in cold wet weather, as the water in there is much warmer than the rain, and wind chill is reduced. In warm weather I often don't use them (e.g. Saturday I was riding all day, mostly in rain, but would have been too hot with overshoes).
I only cycle in waterproof trousers well below freezing, as a third windproof layer over bike tights and running leggings. Even breathable ones are too hot and get very sweaty.   In fact, in summer rain I'm reluctant to wear any form of jacket.  Breathable ones are too warm and  aren't breathable enough, so I carry something thin and light, but end up just as wet from sweat.


How to get weight over the back under hard braking

Hang your buttocks off the back of the saddle is the only appropriate answer.

You can see great evidence of this in cyclocross races when racers go from climbing to steep descents (in some cases) and go straight to the drops and hang their rear end off the back of the bike.

Here is a downhill rider doing an extreme example of exactly this:


What are the differences in mountain bike hubs (With wheelset recommendation)?

I would look at wheelsets that are for your specific riding style. if you're looking to choose a full wheelset from a specific manufacturer (e.g. Mavic) that includes all of hub/rim/spokes and even tire, then go to their websites for more information. These are generally lighter than a normal wheel that you can build up yourself. If you want to build up one yourself, first find a hub that fits your bike. MTN hubs come in various types based on quick release, so check what type of quick release your bike has and then look for hubs that match. as for your question on hub types, here's a quick guide:

ISO: 32 or 36 holes made for wheels that are laced 3 cross. they have a 6-bolt pattern for the disc. see here: https://chrisking.com/hubs/hbs_ISO_disc
in some instances, these hubs can be laced without crossing spokes, but you run a higher risk of hub failure.

Straight(center) pull: this means that the spokes don't cross one another. in other words, they extend straight out from the hub. This lessens weight, but is generally avoided because they place more tension on the rims and aren't as stiff. there are also wheels that will have one side 2/3 cross and one side straight pull. These are for rear wheels and front disc wheels and lessen weight while keeping stiffness on the side with the disc.

Straight Pull center lock: see above for info on spokes. the only difference is that instead of having a six-bolt pattern for the disc mount, they have a shimano center lock disc mount. the advantage of center lock is that they are easier to install (6 individual bolts vs. 1 lockring) which allows them to have smaller hub flanges. The advantage of smaller hub flanges is that wheels are more comfortable to ride (If you've ever ridden a purpose built track bike over potholes, you may know the feeling).

if you have a set of rotors, check what style they are(6-bolt or center-lock) and choose hubs based on those. if you don't have rotors, find the set of brakes you have on the bike, or the brakes that you want on the bike, and determine based on that.

once you have the hubs, choose the rims:
rims come in various styles and sizes based on your riding style. first thing is to check the size of the rim. some models only come in one size (26", 27.5"/650B, 29'er) generally wider equals heavier and more aggressive. most companies that sell rims sell them based on riding style. make sure that the number of holes on the rim matches what you have on your hub.

after that you can choose the spokes and nipples. if you are using standard 32/36 hole rims, and ISO hubs, then just about any standard LBS will have spokes for your wheel. You can reduce weight by getting spokes that are butted/double butted/triple butted, but they are far more expensive. If you get specially designed rims or hubs, you generally need to get spokes that match that rim type. higher end hubs/rims generally require this.

based on your question it isn't clear whether you are against getting a full single-manufacturer wheelset, but I hope this clears some things up and helps you get the right wheels.


A method I've used a lot is after the chain is thoroughly clean but still wet, use an old hair dryer rigged up to be pointed into a small bucket, in which the chain is sitting in a wire basket or similarly suspended. It takes about three minutes to get the chain dry and hot. At the particular shop I was at where this was the protocol, we'd then pull the chain out with a spoke and dip it into a jar of Boeshield T9 for a few seconds, then pull out and let drip dry. The heat does a lot to pull the lube into the inners of the chain, and the results look and feel like a new chain out of the package. I imagine a lot of lubes would have the same result, although you need to develop the system in a way that doesn't cause fires (choice of lube and how hot you get it).

An old toaster oven would probably work too.


Is it not literally suggesting cross-chaining?

Cross-chaining is putting a chain at extreme angle between front and rear cogs. The picture above illustrates correct ways to use the front triple. Incorrect ways would be: the biggest front ring with the biggest rear one, and the smallest front one with the smallest rear one.

I'm also thinking about removing two of the chainrings since only one chainring makes more sense.

I've seen/used the Tourney group and agree that the ratio range it provides is unnecessarily big for flat road applications. However, removing all but one front chainring, in my opinion, will leave you with a very narrow range at the back. Most people will be comfortable with existing two front chainrings of the Tourney setup (the smallest and the middle one), as the biggest front cog only makes sense for quite steep descents and high speeds, unusual for leisure cycling (or at least for non-mountainous terrain).
Note that chainrings on Tourney are riveted not screwed to the spider, so removing them will require some drilling or smashing. Putting them back on will become problematic as well. That is why I do not recommend it.

Say, I make it a 1x setup after removing two chainrings, (keeping just the middle one), will I still meet with cross chaining?

Strictly speaking, yes. The 7-speed chains were not designed to bend through the whole range of the rear cassette. Having a middle front cog with either the biggest or the smallest rear cog will constitute cross-chaining, albeit less grave. It will most likely work, just that it will not be in the intended use/range of the setup, and might lead to decrease in chain/drivetrain life, decrease in shifting reliability, may produce additional noise etc.
On top of that, you may start experiencing chain drops if you remove the front derailleur cage, serving as a chain catcher. True 1× setups have additional measures to increase chain retention, which Tourney does not provide. Again, in the Tourney case, the gearing range will just be very limited.


I just bought a Giant TCX SLR 2, but I still have money to spend. Which parts should I upgrade?

A good investment for someone new to cycling who starts with such a sporty bike is to get a good bike fit. Based on the findings of the fit a part that maybe has to be replaced, is the stem. As these come at different lengths but are not adjustable.

You need to get pedals as well. You may choose between flat pedals, clip-less road pedals and clip-less mountain bike pedals. Each have their advantages as well as disadvantages on a cyclo-cross bike. For the clip-less pedals compatible shoes are needed.

Criggie mentioned in a comment useful tools and accessories that you might need depending on your intended use.

But first of all, get accustomed to the bike and find out what you like to use it for, as this changes everything.

For instance, if you use it to practice CX on a lawn, five minutes walk from your home, you will not need spare tubes and tools on your bike. Conversely, if you ride long remote gravel roads, a days march from the next settlement, you will need to be very well equipped for all kinds of field repairs. In addition, each use case requires a distinctly different bike fit.


What is the most efficient way to ride up or down hills, and into or away from wind?

As you have guessed, it is better to work harder on the uphill and rest on the downhill. And as others have mentioned, whatever works for you on the uphill in terms of balancing high cadence and mashing is best. However, there are a few guidelines that you can follow to approach each situation in the most efficient manner possible.

Downhill: Since wind resistance is the biggest factor in reducing your speed in this situation, you simply want to be as aerodynamic as possible. Tuck yourself into an aero position. Basically, you want your upper body as low and horizontal as possible. Check out pro riders on the downhill of a mountain for visual aids. Use this opportunity to rest and only pedal in short bursts coming out of corners that you've had to brake for.
Headwind: You want to maintain a somewhat aero position, so keep low. However, a complete aero tuck compresses your lungs in your abdomen and you can't breathe as fully as if you were sitting straight up. This means you'll need to find a balance between aerodynamics and being able to breathe efficiently while keeping up a constant cadence and pedal force. You'll also want to keep your arms farther apart because tucking them into the center also compresses your lungs within your chest. Most likely, you'll want to either be in your drops or hunched over a bit with your hands on the hoods.
Uphill and/or tailwind: You can pretty much treat these two the same way since wind resistance is less of a concern than your own aerobic fitness. Just sit up and keep your hands wide to keep your lungs as open as possible and pedal with whatever force and cadence works best for you. Studies confirm our everyday experience that standing while you pedal will increase your speed but is not sustainable for very long. You'll only want to stand up to maintain speed over short sections where the road rises steeply (or more steeply if you're already on a hill), when a brief gust of wind has slowed you down and then let up, or any other situation that briefly threatens to lower your otherwise sustainable speed. If you're running out of energy and only halfway up a hill, standing up won't help you.

Of course, in the real world you never have just a hill or just wind from the front or back. There are cross winds, cross-head winds, cross-tail winds, hills with wind from any direction, and everything in between. Add in traffic concerns, road conditions, etc., and you'll almost certainly have to find a balance between pedaling efficiency and dealing with the world around you.

If you'd like to read more, there is a great article on cycling up and down hills: http://www.sportsci.org/jour/9804/dps.html.

And the ever helpful sheldonbrown.com has an qually excellent article on the effects of wind resistantce here: http://sheldonbrown.com/brandt/wind.html.


Can I mount a wheel with a narrow hub to a wide frame?

The simple answer is yes, you can add washers to the axle and shove it in. If you put all the washers on the chain side the disk brake will still work without modification, at the expense of a crappy chain line (assuming you have derailleur gears - with a singlespeed you'll probably have to change the BB or you'll often drop the chain). Or you can space both sides and the disk caliper with washers as well to even things up (spacing the rotor is fraught as the washers all have to be exactly the same thickness and you can't buy them that way. The failure mode here the the rotor deforming under load and possibly locking your wheel up). It will be almost as strong that way as in the right size frame, assuming your washers are flat and the nuts are done up tightly.

The reason you shouldn't do this, especially with a disk brake, is that there is a surprising amount of force applies to the rear wheel of your bike. By adding spacers you're adding longer levers to the little 10mm axle that has to cope with those loads. Since the initial lever is very short, even a small increase can have dramatic effects.

Think about the left hand side. In normal use the wheel bearings are only 10-15mm away from the dropout. Changing that by 5mm makes it 15-20mm. Which is ok if you started at the 10mm end of the scale, but going from 15mm to 20mm with a design rating of 15mm... not so good.

You will probably get away with this because there's so much excess built into most bikes. They have to be designed to cope with 120kg dudes sitting on the seat as they ride off curbs, so your average 80kg bike nut is just not going to stress the bike the same way. So by spacing out the hub you've shrunk that margin of error, rather than immediately breaking something.


There are multiple possible causes for this kind of pain.

Of course, you should see a medical person in case something more serious is going on than our amateur diagnosis suggests.

In general, this is a kind of overuse injury. This can have different causes (and each would have slightly different symptoms). Part of the reason is that you've taken a break and those muscles are just not as strong as they used to be. Common causes are

The most common cause is your seat too high relative to the handlebars, leading you to put more weight on your forearms. This would be more common for mountain bikes and flat-bars, and seems more likely given the posted diagram.
Another cause to gripping too tightly. You could be gripping the handlebars too tightly, or trying to do too many jumps, etc. This can also be due to repeated hard braking.
You could be overstretching the tendons / muscles, by riding with your wrists low so that your hands are higher than your wrists, or with your wrists bent to the side so that each wrist is bent inwards or outwards. This is more likely on a road bike if you ride with your hands "on the corners" a lot. Or perhaps if the handlebars are too narrow.
Even stranger, it can be caused by pushing too hard on indexed gear levers. You would probably know if your enthusiastic gear changes were causing it.

EDIT

Often the solution to this kind of problem is suggested by the diagnosis but requires some experimentation because the the result of a change can be hard to predict. Everything is interconnected, so changing one thing without full understanding can have unintended consequences. If you make changes yourself then be vigilant for other issues.

Taking the bike to your LBS to get them to check your position is recommended.


Are modern forks compatible with older style bikes?

The technical term is "threaded fork". That is, the steering tube has threads on top for the headset to screw onto. The newer design is called "threadless" - that's the one where the stem clamps onto the steering tube with pinch bolts.

You can switch from one to the other as long as the diameter of the steering tube is the same. (You'll obviously have to use a headset and stem designed for the type of fork you have.) The problem is, the diameter is often not the same. Around the same time as the threadless forks were introduced, they started making the steering tubes and head tubes thicker. The old ones were typically 1 inch (that's the steering tube outer diameter). The new ones are 1.125", sometimes 1.5".

You should measure just to be sure, but I bet you have a 1". It's possible to get a 1" threadless fork, stem and headset, but the choices will be pretty limited.


What is a substitute inner tube for 27x2.125" tyres (in Prague)?

Tl;dr: use 700c or 29"
27x2.125" is very rare.  27x2⅛" would be more likely, and wouldn't quite be the same thing, but for tubes the answer would be the same.  Generally though, 27" tyres are narrower than this, up to about 40mm or 1 1/2"
Schwalbe says that for 27" tubes you should use 700c, which are very common.  The bead seat diameter of 700c is 622mm; for most 27" sizes it's 630mm.  As your tyres are on the wide side, you'd want to use 29x2.1" (as 29" is a marketing name for wide 700c)
Tubes are really rather forgiving.  Examples: I'm currently running a 26" tube in one wheel of my 29er hardtail (a pain to fit, but I'd taken the wrong tube with me and had to get home); I've replaced a tube with a puncture only to find that I'd been riding one old bike for a year on a 26" tyre with a 24" tube.
Note that the width is also given as a range, so one tube might be suitable for 1.5-2.4" widths.  Schwalbe's SV19 is a common example tube, and is specified as suitable for ETRTO diameters from 584mm (27.5") to 635mm (28x1 1/2"/700B) and widths from 40-62mm.  I wouldn't choose it for the very largest diameter and width specified, but it would work.
For info, tyre sizing systems are bizarre - 1/4 is not the same as 0.25 for sizes in inches, and 29"=28", while 27">27.5" (and can be bigger than 29").


Speed to power calc on a 'basic' magnetic trainer

The short answer to your question is: no, there's not enough information.

In the main, the information you lack is about your particular trainer's resistance curve as it varies with roller speed. Each magnetic trainer has a particular "design curve" for its resistance, and you can see some examples here. As you can see, magnetically-braked trainers tend to have a "flatter" power curve than fluid or turbofan trainers. Different manufacturers will use different numbers of magnets and different thicknesses and materials for their rotor in their resistance units. Some magnetic units allow you to alter the distance to vary the resistance. And, each load generator typically has a way to dissipate heat so the load often varies even for the same roller speed when the unit is cool vs. warm. You can often see this by directing a fan at the load generator and noticing a change in resistance. In addition, as parts wear over time the load units and bearings can become misaligned.

You are (almost surely) correct that your total mass (you + bike) is irrelevant since for (almost) all basic magnetic trainers, the roller-to-tire contact is set by turning a knob to press one against the other. That roller-to-tire contact is the same whether you are on the bike or not. When you ride on the road, on the other hand, the road-to-tire contact is determined by your mass. As an aside, trainer rollers are typically about 3 to 4 inches in diameter so for a given total mass the roller deforms the tire more than it would on a regular road surface, so a Newton of force on a trainer roller imposes more rolling resistance than the same Newton of force on a road.

BTW, here is a way to check your "cask on pedal" method for calibrating rolling resistance: Adjust the tire-to-roller contact so that your 5.2kg weight just begins to move the rear tire in a 48-14 gear ratio, as you've been doing. Then, vary the gear ratio and find the pedal weight that will once again move the rear wheel. The ratio of mass to gear ratio ought to be constant.


Finding a road bike for 5'2'' girlfriend

I'm answering the unasked question: "How do I find a hard-to-find bike?"

Certainly this bike exists, but you may have to stick with your search for some time before finding it. (I sympathize with the situation. I take a 19" frame in mens, and most bikes are too large for me.)

Mens' bikes often have a reach that's a bit too long, and handlebars that's a bit too wide for ladies. (Not always, depends on your girlfriend's dimensions.)

Some general thoughts:

Work with your bike shop. They may have something in stock, but more importantly, a good shop will keep an ear to the ground for you.
Try a bike co-op. You may find a used frame inexpensively, or even maybe a complete bike.
Keep searching on Craigslist and Ebay. Learn what frames and bikes you're looking for; on Craigslist in particular, sellers often think that bikes only come in the sizes "kids", "boys" and "girls", and don't list the frame sizes. If you find out what bikes came in the sizes you want, you can at least target your searches better.
Do you have a bike club? Spend time on bikeforums? Subscribe to any mailing lists for bikes? Spread the word!
Did I mention to work with your bike shop?

Stick with it. Keep searching.

If you're not willing to wait, you'll have to either adjust your budget or your expectations. But don't lose hope; the right bike is out there somewhere.


Well, it'll depemd on how the narrower tyre sits on the rim, specifically whether a 25mm tyre will be wide enough, but as long as this is ok, you should be fine. Be aware that wider tyres will have a larger surface in contact with the road, and therefore more grip, but if you're happy to trade that off, go for it.


How to identify/find replacement bolt for STI

You should be able to source a replacement many online industrial parts suppliers. You may not get an exact replacement, but you should be able to get a bolt that works.

Presumably there is a identical bolt on the other shifter. You can use that to find the diameter and length you need. It will be a metric size. I believe that small metric bolts only come in 'standard' pitch. You'll want to get a bolt in stainless steel for corrosion resistance.

In the US McMaster Carr is a well known parts supplier. https://www.mcmaster.com/stainless-steel-bolts


inner tube width range relative to tire width: reliability effects?

If you're getting flats regularly, my guess is that its not the tube's fault, but you to need to make sure that you have sufficient tire pressure and switch to puncture-belted tires (e.g. Schwalbe Marathon). A tube is just a balloon, and you can often put a tube marketed for a not too different size tire into one which slightly different without problems (so long as you don't have the extra width bunch up; e.g. don't put a 29x2.5 tube in a 700x18 tire; I normally do this with 700x23 marketed tubes in a 700x28 tire without problems). Just like most balloons, even the smallest prick will deflate it, so you really need to protect the debris from getting to the tube in the first place. The thickness difference between the rubber in the bigger and smaller tubes will likely be too small to make a difference. And in this case, since the tube is designed to work for tires of your size in both cases, you should expect to have perfectly acceptable behavior with both sides (that is, dumb luck should determine which works better).

Empirically, if anything, the brand of tube might have a slight effect. I've had bad luck with tube reliability from one manufacturer in particular, so I don't buy their tubes anymore.

If you're really paranoid, they make tubes which have extra thick rubber called puncture resistant tubes (useful if you have goatheads) and you can fill your tube with tire sealant (Slime). These will be more resilient to punctures compared to other tubes, but they are more expensive and Slime is messy. But I'd start with some puncture resistant tires. In short, if you don't have these speciality tubes, its likely the case that it doesn't matter which tube you have.

I'd suggest avoiding using tire liners, since they can actually increase flats unless you're really not in good shape. A puncture belted tire is a better idea for most people.


Is it worth to get a Bianchi Caurus 909 and rebuild some parts?

From economical standpoint, rebuilding bicycles is almost always unreasonable. For the same amount of money spent on replacement components, it is often possible to buy a new decent bicycle of the same or better level, thus saving workshop time.

If, however, money is not a deciding factor for starting a rebuild, then the answer depends on whether you like spending your time with bike tinkering, and have no other better/enjoyable things to do. If you do enjoy working on your bikes, restoring old things, or want to learn new skills and things, then go for it — wrenching on a bike is often a rewarding experience.


What's the most useful style of chain gauge?

"Useful" is hard to define for everyone. For me, "useful" tends to mean "has a lot of uses". The very specific chain wear-checking tools you list above are "handy" in that they do one thing and they do it reasonably well. Useful? Well...if you need to do it a lot and/or it is difficult.

But there is a tried-and-true method using a simple tool that many people already own, and which has a lot of other uses: a tape measure or ruler with inch markings. You simply align an inch mark on one side of a rivet, then look at the corresponding rivet 12 full links away. On an unworn chain, the rivet will line up exactly at 12 inches. A worn chain will be more than 12 inches. On most bicycles, you won't even need to remove the chain to do this. And it works with virtually all modern bicycle chains.

Chain wear in general is a bit of a "religious" issue, but a rule of thumb if you must have one is: within 1/16 of an inch, no problem. Between 1/16 - 1/8 of an inch, probably time to replace the chain. Past 1/8 of an inch, you've probably noticed other issues in the drivetrain.

This (along with many, many other chain-related issues) is summed up nicely at Sheldon Brown's site (see 'Measuring Chain Wear', towards the bottom).


How can I tell number of speeds on my road bike? 9, 10, 11?

Traditionally 'speeds' meant the number of gear configurations available. This is the number of sprockets in the cassette (or on the freewheel for older bikes) multiplied by the number of chainrings - hence the iconic '10 speed racer' for a bike with 5 sprockets in the rear and 2 chainrings.

These days people tend to use 'speeds' to refer to just the number of sprockets in the cassette, and it seems to have come to refer to the technological advancement or quality of the groupset, as newer more expensive grousets have more sprockets and older or cheaper groupsets have fewer.

If you want to talk about the number of gear configurations you bike of groupset has, most people now write [number of chainrings] x [number sprockets in rear], e.g. '2x11' (spoken: 'two by eleven') instead of '22 speed'.


There are several questions here.
You were on a road trip and found a hole in your tire...

I swapped front and rear tyre to have the weak one in front because it gets less pressure. Was this correct thing to do? Also, should I have deflated the air pressure in tube when I saw this?

And...

Should and could I have put both my old and his old tyre to prevent leak of the tube? It seemed like a good idea, especially because they were damaged at different places, but I didn't want to risk some other stupid thing that might have happened. If that would have been a good idea, what about if the tyres were damaged at the same spot? Would then make sense having both of them?

To summarize:
You found yourself in a bad situation and improvised several amazing solutions using what you had on hand to get a little further down the road until you had no choice but to walk.
Your solutions were the best you could do in the situation.
Suggestions:
Do an equipment check and solve problems before you start your road trip. Identifying marginal tires, brake pads, etc. and doing basic maintenance before you start on a trip will reduce (not eliminate) issues on the road.
What your bring in the way of spares and tools depends on how long your trip is.
You brought a spare tube and the tools to install and inflate it - which is excellent. On your next trip consider bringing a spare tire. As a rule of thumb its nice to have a spare tire if you are going to be riding further from home than you want to walk back. Even if your tire is new they can be damaged while riding in a way that requires replacement.


I need to identify what kind of bike I have

The logo is that of Mirraco BMX, which was started in 2006 by the late Dave Mirra. Mirraco got out of the BMX business in late 2013 or 2014. You might be able to match up your bike with some of these on RBikes.


It seems that brake pad is touching your tire on the one side. Make it parallel to rim and/or move it a little bit down, if you don't same thing will happen to your new tire!

(via http://www.parktool.com/blog/repair-help/linear-pull-brake-service)


If many bottom-outs are happening, should air pressure or compression damping be increased?

Increasing positive chamber pressure would reduce bottom-outs, but at the expense of reduced "up" travel.  Increasing compression damping will also reduce bottom-outs but without reducing "up" travel.  This would have the negative effect of reducing the shock's compliance which will make the ride harsher, so it's a balancing act where the goal is to optimize the shock's action for the riding you do and how you want the shock to work for you.  If you mostly ride smooth trails but with occasional drops, then increasing positive chamber pressure so that you can keep compression damping low while still not bottoming out very often might work best.  If the shock is bottoming out every time you hit a big rock, then may you have to increase both positive chamber pressure and compression damping.

If you can't find an effective combo that doesn't reduce bottoming out, then maybe you need a longer-travel fork.


Bike computer that logs all data to smartphone

Yes, but the SRM computer is designed (and priced at close to $800) with the professional athlete in mind. It is said to autostart.


Sorry to hear someone vandalized your bicycle. I've been a bike mechanic in the past and there is a point of no return for rims in my opinion. This issue is that point can be subjective based on bike use and needed quality. From this point on, the wheel will tend to come out of true easier due to the weakened rim. Interesting, what you did by stepping on the rim I've seen done at shops and recommended in how-to videos. You can get a spoke nipple wrench and improve the rim by truing between the brake pads. Grep "how to true bike wheel" on Google for a start. I've seen side-to-side improve a bit in extreme cases but up/down hops will be harder to get out. If you do take the self-serve option remember use little corrections at first. Also, attempt to keep all spoke tensions even. Taking it to a shop is an option but labor plus and parts will be a chunk of cash towards a new wheel at the end you'll still have a wheel on a rebuilt rim. Finally I don't know how the bike shops are in your area, I would give you a free assessment if you came to mine. After all this, if the wheel refuses to stay in true sorry but it would be replacement time.


Would using compressionless brake housing for derailleur be a problem?

It's fine as long as there are no unusually tight internal routing frame fittings that will only play nice with a 4mm shift housing, rather than a 5mm (all modern brake housings, compressionless or coil, are 5mm). I can't think of anything like that I've seen offhand, but the array of housing ports and guides that frames have come with is now pretty vast, so there are probably examples out there.

I've done this many times using Odyssey Linear Slic and similar BMX cable kits for funky color scheme purposes. Also from observing how low-friction they can be even when wrapped around bars multiple times, I personally also suspect that braided (aka compressionless brake) housings work a little better than everything else in routing schemes with tight housing bends. I don't have any proof, but I've used them successfully for this purpose on at least a couple bikes with horribly designed internal routing.

The bigger cable/liner gap does not make any difference in practice. The cable is following the path of least resistance and is under tension. Remember that standard 4mm and 5mm shift housings both work totally fine, and they have different amounts of gap. It's uncommon to see 5mm compressionless shift housing on new bikes now, but it was very common for a long time.

Ferrule outside diameter is the same across all the common ferrule types (4mm shift, 5mm shift, 5mm brake, and 5mm compressionless/braided anything). Compressionless brake kits and rolls usually come with special stepped-down ferrules, like the Jagwire POP ferrule, that are intended to be used on brakes and levers that were designed to not use a brake housing ferrule at all, such as many caliper brakes and brifters. Ferrules with an appropriately thick end surface are required on all types of compressionless housings because other wires will blow through over time otherwise. If the extra length of the stepped ferrules is causing an awkward bend, and the part in question can take a normal OD ferrule, it's fine to use a standard 5mm brass or aluminum shift ferrule instead. (But not a 5mm brake ferrule, because the thin end surface won't be strong enough to keep the wire blow-through problem from happening over time.)


Putting a longer travel fork on a bike not designed for it will alter the geometry of the bike, and usually the handling.  Depending on the amount of change, it might be barely noticeable, or it could also appreciably degrade the ability of the bike to be ridden.  You could put a 200mm travel fork on a road frame, but the resulting geometry would render the bike unfit for anything serious.

The change you are talking about will likely result in a rideable but slightly awkward ride.  It's unlikely you'll snap your frame (highly unlikely).  However, it's far more likely that if you use the front fork (a 200mm dual crown monster) to it's full potential, you blow out/prematurely wear the rear shock which is not designed for that kind of abuse.  Considering what a fork like that (or a replacement rear shock) costs, you'd probably be better off selling that bike as is and trying to by a bike more suited to the type of riding you are planning.


It’s much easier to push than it is to pull.

So I suggest you remove your bottom bracket entirely and then push the spacer all the way down into the bottom bracket space where it can be then cut, folded, spindled, and mutilated.

Appropriately sized wooden dowels or PVC tubing would be your best bet if you didn’t want to mar the seat tube. Very long handled minus screwdrivers can be used if you don’t care anymore. An aluminum spacer may have cold welded itself to a steel seat tube and in those cases, chemical or thermal assistance may also be needed.

Ps. I don’t actually see a seat post clamp on your bike in your pictures and so I’m assuming you do actually have one.


Sachs Torpedo 3 gear vs. SRAM T3 vs. SRAM i-motion 3 gear

SRAM acquired Sachs in 1997.

The main visible difference between the (Fichtel &) Sachs Torpedo 3 hub and the SRAM T3 is that the SRAM T3 comes in an aluminium body, whereas the Sachs Torpedo 3 comes in a chrome plated steel body and the brake design has been changed (but is compatible). There apparently was a successor model to the Sachs Torpedo 3 called Sachs Spectro T3 in between the SRAM T3 and the Sachs Torpedo 3. Around 1996 the coaster brake mechanism was changed by Sachs. So the timeline is:

~1977: H3111 (Sachs Torpedo 3) -> ~1996: MH3111 (Sachs Spectro T3) -> ~2000 MH3115 SRAM T3.

For the (Fichtel &) Sachs Torpedo 3 (H3111) speed hub see:
http://www.scheunenfun.de/f+s_h3111.htm (German)

For the Sachs Spectro T3 (MH3111) and the SRAM T3 (MH3115) see:
http://www.scheunenfun.de/sram-t3.htm (German)

So those mentioned above are internally compatible, at least if you're willing to replace some parts.

I am not exactly sure about the i-motion 3, but SRAM states that it is the successor of the T3 hub (see http://www.sheldonbrown.com/harris/pdfs/sram-internal-gears.pdf) it has a different shifting mechanism (a broken cable leaves it in low gear (opposed to high gear on the T3) among and some other differences, as far as I can see (see http://cdn.sram.com/sites/default/files/techdocs/sram-techmanual-my10-gearhubsystems-english-reva.pdf) and the internals are not compatible with the t3.

Some people have had problems (broken axles) with the i-motion 3 hub, whereas the old Torpedo hubs rarely break, which should be the case for the T3 as well, as it is mostly the same design (see http://www.bikeforums.net/archive/index.php/t-394516.html).


Warmshowers is certainly not a "social" network in the meaning of socializing only on the internet. But it is an internet-organized network for socializing with other cyclists in the real world. Certainly a good fit to this question's tags touring and social. It's a great opportunity to meet really nice and interesting people - highly recommended!


The item you removed (BB-06-PSPL - 113/68) is the bottom bracket. The 113/68 means that it s 113mm spindle length and 68mm bottom bracket length this means that it is a standard size and will be easily replaced. The PSPL means that it has a Powerspline interface with the cranks, this is a Truvativ/ SRAM proprietry system so if you wish to keep the cranks you are using you would need a replacement Truvativ cartridge.

If you are willing to change the crankset as well you are not limited in any way as long as:

The bottom bracket is 68mm and English thread and has the same interface as your new crankset, or you could choose and external bearing set up.
The crankset is built for the right drive train, if you have a 9 speed rear derailleur you need a 9 speed crankset as chain widths are different.
You can achieve the same chain line as your current set up with a new crankset through selecting the right spindle length.  (this may take a few internet searches for Shimano this is available in the Tech Docs for each crankset).


What is the lifespan of a typical road tire?

Here is Sheldon's take on it: Your backbrain should be niggling you when you start to get some punctures or the fabric layer/belt (which gives the structure of the tire) of the tire is about to show or is damaged. Unlike a radial, where the tire is integral to keeping the wheel working, all a tire has to do is protect a tube. The rest of the stuff is aesthetic. Proper inflation is important for controlling wear though.

Schwalbe's marketing material says that Schwalbe Marathons should last between 6000 km and 12000km, but I'd be inclined to say thats conservative in good riding conditions - I have much lower quality tires than Schwalbe Marathons which are closer to the higher end of that range and show no signs of giving up (this is for commuting, and they have around 7000 miles on them, but this is on a 26" rigid mountain bike so significantly bigger tires than you're likely considering, so maybe not a fair comparison).


Are the wheels of Thule and Burley two wheeled trailers interchangeable?

Got a reply from a dual owner (burley and Thule) that they have a slightly different axle-witdh (should have been thickness). :(
https://thismombikes.net/child-trailers-chariot-vs-burley/


Can I change from short to long derailleur to increase cog size

It doesn't look like you'd be able to use an 11-32T cassette at all with a 10-speed Tiagra rear derailleur.  From [Shimano's documentation] (http://bike.shimano.com/media/techdocs/content/cycle/SI/SI_5XN0A/SI-5XN0A-001-Eng_v1_m56577569830746860.pdf), the largest sprocket that either the short cage or long cage version supports is 30T.  If you wanted to use their 12-30T tiagra cassette, you would need the long cage because the tooth difference has to be 16 teeth or less for the short cage, whereas the long cage supports a tooth difference up to 22 teeth.

If you really want to go up to 32T and stick with a road derailleur, it looks like you'll have to upgrade to the newer 11 speed stuff and get the long cage version.  The [11 speed Ultegra] (http://bike.shimano.com/content/sac-bike/en/home/road/shifting---braking/rear-derailleurs/rd-6800-gs.html) derailleur looks like the only road derailleur from Shimano that would support an 11-32T cassette.  Incidentally, that's the derailleur that came stock on my 'cross bike and it's got an 11-32T cassette on there.


Does anyone have experience with Bottom Bracket Tap/Facing sets?

Bottom Bracket Taps and Facing tools are an expensive and highly specialized tool. As a workshop, owning them and knowing when and how to use them properly, is one of the key signs of a professional shop.

Many new frames are moving to design without threads, but these tools will continue to be valuable for years to come.

These are the brands I'm familiar with, and recommend:

The Park Tool set is quality, and durable. For a set of taps and facing blades that will be durable, and also are likely to maintain compatibility with future similar tool sets from Park, it's hard to go wrong there.

The Campagnolo set has been the quality standard for shop use for 30 years at least. I know of one shop that's had theirs in continuous use for at least that long. You do pay for it, and the Campy tap set is a separate tool.

The Cylus Tap sets are excellent as well, although durability is yet to be proven. They are a more complicated machine, which allows a speedier, and very well done, job to be performed. It also allows for more things to break on their system. This is an impression I have only. I have not seen one fail. It does require a separate tool for english and italian BB's, and the parts are not interchangeable.

The VAR tool set is the original, the one that Park Tool based their original design on. It's simple, durable, and classic. The design allows purchase of an Italian thread set to be used with the English handles, and vice versa.

Hozan Tools makes an excellent tap set, but not facer currently.

All of these tools are excellent quality and have reasonable likelihood of replacement taps and facing cutters being available through the years. Campagnolo, and Park Tool are fairly certain to stand the test of time, and I'd recommend on of those two.


What are the minimum requirements to commute comfortably through the winter?

The bike doesn't matter that much, except when there's snow or ice on the roads.  What you need most is the right clothing.  It needs to be well-adapted to cycling (not loose or apt to get caught in the chain), layered so you can take off pieces BEFORE you get too warm, with wind-resistant and rain-resistant layers.

Your shoes need to be somehow protected from wet spray, with rubber booties or such.  Wet feet can get VERY cold.

Lots of opinions on gloves -- you should probably have several pair, from warm "ski gloves" for really cold days to lighter-weight gloves for most days.  "Glove liners" are a good idea -- you can use them alone (under regular cycling gloves) on warmer days, and they come in handy when you need to work on the bike in cold weather since you can work reasonably well with them on.

For the bike, any bike will work for plain rain or cold (though fenders are nice in the rain).  For riding in actual snow (where the roads have not been cleared) you want a substantial tread, and possibly lugged "mountain" tires.  For any sort of ice you MUST have studded tires -- riding on ice without studded tires is suicide.

I don't feel that commuting is apt to "ruin" a bike, but you probably wouldn't want to subject a $6000 bike to the bad weather, road salt, being parked outside at the other end, etc.  And if you do want to ride in the snow and don't already have a bike suited to knobby tires, it does make sense to purchase a modest "mountain" bike.

Added:  Forgot to mention the head.  I always wear a helmet, making a bulky hat impractical.  At one time I had a "helmet liner" (probably purchased from Performance or Nashbar) that was a sort of diamond-shaped piece of blue polypro fabric with loops to fit the helmet straps.  This worked well -- kept the ears warm in fairly cold weather, which is the main challenge -- but I lost it and never found a replacement.

I've tried several balaclavas and face masks but never found one that would fit comfortably, without either obscuring vision or interfering with breathing.


There are three "parts" or zones to a cable-operated brake.

1) The hand lever
 2) Inner cable and outer housing
 3) The caliper.

So you released the inner cable from the caliper.  Try pulling the cable through the outer housing and see how much hand pressure you need to apply... it should be relatively minimal.  If you have to get a good grip and pull with shoulder muscles, then the cable is suffering friction with the outer.

The fix here is to replace both the inner cable and outer housing.

With the cable disconnected, the lever should have tension and pull itself back to the open position without problems.  If it doesn't restore by itself, then it may be corroded, or deformed (ie plastic or metal bent)

You do say cheapo kids bike which normally means terrible plastic levers and budget stamped metal single-side pull calipers.  Sometimes these just get tired and the spring power is not enough to overcome the resistance from the inner cable.

Sadly some cheapo bikes are really not worth fixing - you have to make a judgement call.


Counter to the answer that 'cmaster - reinstate monica' gave, you CAN put your backpack directly in a basket on a rack. It's easy!

Install a rear rack as many other answers suggest. If you're not comfortable doing this yourself, have a shop do it for you. Get a full rack, not one that relies on just clamping to the seatpost.
Get a milk crate as a basket. Don't laugh! Milk crates are often easy to find and can be free if you look around hard enough. They're tough and are not affected by water or temperature extremes. They have wonderful handles that assist in moving your bike around.
Attach the milk crate to the rack using metal hose clamps. You might be tempted to use zip-ties. Zip-ties do work (for a while), but become brittle with age and will break at the worst possible time (when your crate is heavily loaded).

Putting your back-pack in your milk create is easy! Just throw it in! The high walls will make sure your bag stays in. If you're concerned about it falling out, use an old innertube tied between the handles on the side. (An old innertube makes a great tie-down for other things in your crate as well!)
Your bike is now much more useful. You can stop for a bag of groceries which fit nicely in the rack (and your back-pack can go on your back for that leg home from the store).
Do a google image search for "milk create bike" and you'll see some examples.


What steps should I follow to patch a tube?

Somewhat generic instructions for using a patch kit:

Remove the wheel from the bike, check for obvious damage to the tire
Remove the tube from the tire

You can use tire levers to remove the tire from the rim. Be sure not to add additional punctures to the tube by pinching it with the levers.

Note the orientation of the tube within the tire so you can trace down the puncture point.
Find the puncture on the tube

May help to put some air in it and use your cheek/eye to feel for leaks.

Once you've located the puncture, find the point in the tire where the puncture occurred and make sure there is nothing stuck in the tire (like a shard of glass) which will re-puncture the tube.

Assuming it is a puncture and that the tire isn't actually torn/worn through, you can proceed to patch the tube. If the tire is too damaged the tube will just pop again, so there isn't much point.
Apply the patch

Typically this involves gently sanding/roughing up the surface of the tube, applying adhesive compound, letting it dry for 5-10 minutes, and then applying the patch. Most patches I've seen have a brown side, and a black/brown side. The black/brown side stays upwards, the fully brown side is applied against the tube. Wait another 5 to 10 minutes for the patch to bond to the compound.
Install tube in tire

Inflate the tube slightly to make sure it holds air. Insert it into the tire, then mount the tire on the rim, one wire bead at a time. The first bead should go on easily, the second may require tire levers or strong thumbs.  Be very careful not to puncture the tube if using levers.

I find it helps to completely deflate the tube to get the last bit of the wire over the rim. There are some good tutorials on getting the last bit of the wire onto the rim, which can be tricky to do without damaging the tube.
Inflate tube, checking again for damage/bulges/splits as you approach full pressure
Ride away


Is it possible to combine rod brakes with a coaster brake?

You won't be able to simply bolt on a coaster brake. Coaster brakes are typically built into a single speed or 2 or 3 speed internally geared hub.

To fit a coaster brake you will have to replace the rear wheel hub, which obviously means a wheel rebuild, or whole new wheel with a matching rim.

Whether a modern coaster brake hub would fit in your frame depends on the dropout spacing of your frame. I guessing that single speed or 3 speed coaster brake hubs come in narrower widths as used on older bikes, likely around 120mm.

If your bike already has a internally geared hub then there are extra complications, if you replace it with a modern internally geared hub you need to fit a shifter and necessary cabling.


Advantages with longer seatpost in the seat tube?

Frames have a minimum insert requirement - 100mm-120mm for carbon is not uncommon. Seat posts also have a minimum, which is usually marked on the post - typically 75-100mm.  Both these limits should be adhered to. A long seat post may be too long to lower the seat to the correct position.  The difference between the minimum insertion and maximum will vary based on the frame, however it can be quite a small range especially on some more exotic shaped frames (e.g. Softtail MTB's)

The only advantage of going to the minimum insertion is weight savings. However going short adds stress to the seat tube.

The only significant disadvantages of a longer post is weight.

What length post to use between these minimum and maximum insertion depths will depend largely on your own preference for weight saving over strength and your weight and riding style.  My lightweight XC MTB  has 100mm inserted (100mm minimum), but I am 66kg, and don't do jumps. If I was 120kg and loved big air, it would have 200mm or more.

You can cut the end of the current seat post. Find the minimum insert for the frame and post, measure that much below the current posts location in the seat tube and rip into it with a hacksaw. When I have done this in the past, I also sand off the minimum insertion mark put a new one on the post.


Chain skipping on new single speed freewheeel

One two options given that your freewheel is new:

The chain is too loose. A chain tensioner might help. Alternatively, if you have semi horizontal dropouts just pull the rear wheel back and tighten.
The front chainring is worn. This has happened to me before. Replacing the chainring solved the problem.


What are the standard shifter designs and mechanisms?

With the exception of the new electronic stuff, every shifter out there that isn't the old friction style works on a ratchet and spring mechanism to index the amount of cable being pulled or released. Is that what you are asking?


Sorry, that frame will not take larger wheels.

Triathlon/aero bikes have minimal clearance between frame/fork and wheels which do not even allow larger tires in some cases. Additionally, bikes equipped with rim brakes will not take different size wheels because the brakes will not line up with the rims.

The assertion about smaller bikes needing smaller wheels to maintain geometry is true.

An XS size sounds too small for someone 167cm (5'4 1/2"). As you bought it used you may want to consider selling it and looking for a bike the next size up.


How to waterproof Shimano dynamo connector?

I use ShoeGoo or Sugru (you can Google both brand names) for waterproofing connectors.

The advantage of both is that they are flexible and waterproof, but also relatively easy to remove in the field without any gooey residue (which tape tends to leave). I also find it hard to use shrinkwrap to waterproof connections where the diameter of the two parts is more than 1:2 in ratio, because of the limitations of the shrinkwrap shrinkage. Nail polish becomes very brittle very quickly.

For the dyno connector, I'd use ShoeGoo. Assemble the connector. Put just a very small (lentil pea) size on your fingertip and rub it in like caulking compound on the outside of all mating surfaces. You want to get into all the cracks but you don't want to apply too much and weld things together. . This ensures that you'll be able to still take it apart in the field.

The one exception is where the wires enter the connector body. I might put some ShoeGoo on the outside of the wire before sliding it fully into the connector to ensure that it's well sealed.

As Daniel Hicks has mentioned, some dielectric grease on the bare wires will help. You can get a tiny squeeze tube at the checkout counter of the auto parts store for under $2.


How did cyclists get over curbs before BMX era?

People were doing tricks on bicycles almost as soon as they were invented. While I couldn't find references about curb hopping in particular, I'm pretty sure that these tricksters from the late 1800s wouldn't have had a problem pulling it off.

Cyclocross has roots that go almost as far back. The first organized cyclocross races were around the end of the 19th century and the first French National Championship was in 1902.

I would guess that prior to BMX most people got over curbs the same way that most people get over curbs today. They slowed down a bit, lifted the front wheel over the curb, and leaned forward to get the weight off the rear wheel. Keep in mind, most cycling commuters can't pull off a decent bunny hop and many commuter bikes aren't designed to do so.


Specialized rockhopper crankset replacement - please help

Stout is a captive brand for Specialized, so if you want an identical replacement, the first place I'd go is to the Specialized dealer who sold you the bike. They should be able to source replacement parts. If you didn't buy it new, just find a Specialized dealer near you.
Alternatively, you can look online for a matching crank. The ones you'll find for sale are usually used or taken off of a new bike, since these cranks are not sold separately in other stores.
Note, though, that if only one arm is cross-threaded (usually the left because people try to put the pedal in as if the threads are normal right-handed), you might not need to replace the whole crank. You might be able to just replace the damaged part.
If you aren't attached to that specific brand and want to replace the whole crank, another option is just to buy a different brand crank that is compatible with your bike. The key specifications are the bottom bracket type (yours is square taper, though you often buy a new BB with a new crank anyway), the width (73 mm), the number of chainrings (1) and the crankarm length (175). The 73 mm standard is very common for mountain bikes, so you should have no trouble finding many options for replacement cranks.


What bike should I get? For forests and city mainly

I don't think there is anyone who can tell you what you will like.

It's all about the test ride.
If there is any way you can rent/borrow or test ride at the bike shop lots of different bikes to get a feel for the differences in the different kinds of bikes it's the best way to know what you want/need.

It's all about trade offs and the best way to know is to get out and try things. Build up your knowledge of how different bikes feel so you can make an informed decision.

Sometimes you can get something you really like by going to wider or narrower tires and a different seat.


Do I need to replace my chain ring and cassette? Images attached

The idea is that chain force causes wear on the edge of the upcurve of the U-shaped gap between each gear tooth, eventually eroding the tooth profile so much that it becomes V or shark-tooth shaped in extreme cases (instead of flat-topped).  The gear gap where the chain roller sits is then much wider than the roller itself, and the gear tooth is much narrower than the gap between rollers, so the chain can have slop and even slip on the gear, causing problems.
Steel gears will normally wear more slowly than alloy gears, and chainrings (front) will normally wear more slowly than rear gears of the same material.  The chain roller connections will also wear (this is called "stretch" but is just wear making the chain looser). Normally, chains get replaced more often than rear gear cassettes, which in turn get replaced more often than chainrings, but it will all vary with the materials and riding style involved.


What type of bike has the most similar feel to a stationary bike?

This really depends on the type of stationary bike you are talking about. There's the older style as well as bikes that resemble road bikes (at least in terms of body position), as well as some recumbent bikes. There are bicycles that match pretty well to all three of those stationary bikes.  However, it's worth mentioning that just because you are comfortable on a stationary bike, does not mean you will be comfortable on a bike with the same posture.  For instance the first bike I linked to is very much upright.  A bike like that would be fine for a quick trip to the corner store, but you would probably tire of it quickly if you were trying to get some serious exercise.


Crankset arms length and chainring for 5 year-old

Gearing is a very subjective question.

Using Sheldon Brown's Gain Ratio Calculations, 36:17 on 110mm cranks will give a 1.25% lower gain ratio than 38:35 on 130mm cranks.


You are correct.  The reason for the rebound control so so you can adjust the fork for your riding.

If the rebound is too fast, the fork acts like a pogo stick - you hit a bump, the fork soaks it up then 'pings' back so fast it unweights the front wheel, (with fairly predictable consequences) when it happens while cornering.

If the rebound is too slow, you go over a bump, the fork soaks it up, but before it rebounds back you hit the next bump. A few bumps later, the fork is at the bottom of its travel (with predictable consequences).

The trick is to adjust the rebound so its fast enough that the fork recovers without bottoming out, but slow enough that it holds the front wheel firmly on the ground. There is a little science behind this, but as every rider, bike and trail is different, there is not way to tell you how you should set your fork up.  On top of all this is (if its an air shock) - the amount of air pressure in the shock affects the amount of damping needed.

If you have air shocks, there is now some science around setting them up - you can buy/beg/steal/hire a Shockwiz


Any way to transport kids on a folding bike?

In my opinion, this should NOT be done.

Bicycles are very versatile, and one can not only use a single all-purpose bike for many purposes, but also to have/design specialty bikes, as it is the case of a Strida. And, by the way, is the case with a lot of child-carrying specific bikes and/or equipment.

But, as it seems to me, a Strida is a SPECIALTY BIKE NOT SUITABLE TO CARRY CHILDREN! It has its purpose (portability and compactness), and this purpose is not compatible with child-carrying, unfortunately.

My suggestion would be to increase your fleet, just in case you really WANT to carry your child on a bicycle, which by the way is an EXCELENT EXPERIENCE with no age limit! (only size/weight limit)

Hope this helps, and I didn't mean to be rude or disappointing, but concerned with the child's comfort and safety.

(by the way, transporting kids ALWAYS defeats the purpose of compactness, whatever "compactness" might mean...)


What power adapter to use for the Cybex 700 stationary bike?

Most information appears to have vanished from the official website, but other specifications suggest it's just a 12V power plug.
I've tested a universal power supply and 12 V, 1 A turned out to work fine with the Cybex 700. The correct plug was the green one in this model (6.3*3.0 mm).


Has bicycle gearing become 'easier' over the last few decades?

I think gearing has become more "complex" over the last few decades, but I wouldn't say its become "easier." Material weight of the frame and parts have gone down on affordable bikes, which translates directly into a lighter bike under the average rider. Also, There are a number of people who believe that a higher cadence isn't a bad thing:

http://coachlevi.com/cycling/high-vs-low-cadence-pedaling-speed/

Also, most mid-level road bikes have a large cog of 52/53 and the rear cassette will go down to 12. so thats pretty close to your granddad's ratio!


What hand signals are there for communicating with others when cycling in a group?

Yeah, what Stephen says is about all I know (though I don't run with the racing crowd).  Pointing at road debris is commonly done, but probably useless, since it doesn't allow time to react -- I prefer to just yell "Trash!", especially now that I have a bad arm and the signaling is more difficult.

Using the hand signal (left arm (US) extended with elbow bent downward at about a 45 degree angle and with open palm facing backwards) for slowing is a bit more useful than pointing at road debris, but shouting "Slowing!" or "Stopping!" is still a better signal -- easier to accomplish, and more likely to get the attention of the rider behind.

And, of course, there's the shouted "Car back!" signal given from the rear (no possible hand signal here) when a vehicle is overtaking a group of bikes, and "On your left/right!" shouted when overtaking another bike.

(I'm sure that some cycling groups have additional agreed-upon signals, but I don't know of any others that would be generally recognized in the US.)

For motorists, I use the basic hand signals -- left arm extended for left turn, right arm extended for right turn.  I occasionally use the "slow" signal (described above) when needed to signal that a motorist needs to use caution (because, eg, of cyclists ahead that he may not be able to see), and I've used it once or twice when occupying a full lane to signal that I'm going to retain occupancy (such as when negotiating a single-lane bypass through a construction site).  I also sometimes use the left (US) hand extended, palm down, with a repeated downward motion to signal "slow down", when there are cyclists or some other hazard ahead.

When following others at all closely, cyclists need to learn to watch the feet, rear derailer, and rear brake caliper of the cyclist ahead.  These signal speed changes, and careful observation will clue in the cyclist behind even when the cyclist ahead fails to somehow explicitly signal.


Most probably not.

There’s no standard communications protocol for motor controllers and displays. Each manufacturer has their own system.

Adding to this, you’ve listed a controller which could have come from any dozens of factories using any number of generic designs. It’s not even clear if your controller has display support — looking at the wiring harness on the listing  I don’t see a lead for a display controller:

But many times the listings are incorrect and you get something else in the box, so who knows?

Unless you can find someone who says it works or who has tried it, there’s no way of knowing. That said, many things on amazon have a 30 day return policy so you could be the first.


Looks like you have done the research and You have a good idea of what you want to do and how you are going to execute it. You have a torque wrench and know what the torque specs are.
The only thing I have found difficult about crank replacement is the axle can be tight in the bearing inner races and requires some force to get it through.
If you want to learn go for it. If things go wrong you can always go to your LBS.


Looks like a Specialized Epic frame.
Hate to post an ebay link but they had good pictures. And when I say "good" I mean that there were many detailed shots. The pictures are of a pretty frightening frame.


There's a common enough drill that we teach kids on our HS MTB team that could also serve as a warmup.  The idea is to practice keeping the body vertical (and off the seat, of course) while turning the bike into the turn.  The foot on the outside of the turn is kept down.  A variation (an "I trust my bike" exercise) is to maintain that posture while keeping the bike moving straight-- essentially riding straight on the side of the tires.  The first exercise is more useful, imho.  We've seen an improvement in confidence as the kids understand a bit of the physics of the turn and see that there's more to it than, "fling yourself into the corners and hope the brakes are good enough".


The advantage is that it's quicker and easier to get the tube out and tyre off, and you never have to deal with jammed nuts.

IME the nut will be wedged unbelievably tight the one time you get a puncture at an inconvenient moment, and you'll end up breaking the valve (if you have pliers) or not being able to get at the hole (if you don't). The problem there is that you do the nut up firmly when the tube is inflated to 100psi, then it goes flat and without the air pressure "firmly" becomes "OMG".

The fix for that over-tight nut is obviously to inflate the tube. Which is fine if there's a wee hole somewhere away from the valve, but if the tube burst or you brought a spare tube instead of a patch kit you just have to somehow get the value out of the tyre. Which is surprisingly hard to do if the only tools you have to hand are whatever is on the side of the road.

Disadvantages of leaving it off: The nut is slightly useful if you have a flat-section rim drilled for Schrader values, in that it stops sand and muck getting in through the gap between the valve and the rim and rattling round in a hollow rim or causing punctures. Obviously this isn't an issue if your rim is drilled properly, and a better solution is to buy tubes with Schrader valves.

The nut can make putting a loose tyre back on by holding the bead in place by the valve while you try to balance the bead around the rim so it doesn't blow off. But a properly fitting tyre doesn't do that. And you could carry one nut in your repair kit, rather than one on each wheel (a saving of at least half a gram!)

(edit) the nut has to be tight enough that it doesn't loosen when the tube is fully inflated, but not so tight that it's hard to undo when the tube is flat. But often when you tighten it with the tube flat, when you pump it up the nut turns out to be loose. So to get it right you need to let the air out of the tube, tighten the nut some more, then pump it back up. Possibly more than once. Or you can tighten it once the tube is inflated and hope for the best. In which case you can easily end up back at the start of this answer.

The other 99% of the time the nut does nothing harmful. Nothing very useful either. It's just there.

(edit) Note that the question is not "what are the advantages of using the nut" or even "how do you use the nut", it is specifically "advantages of not using the nut". I don't think "if you do this the nut works fine" is an advantage of leaving the nut off.


I don't know why, but Merida seems to be confusing the terminology. Cross is typically short-hand for cyclocross and used interchangeably. If you told me you were looking for a cross bike I would instantly assume you mean 'cyclocross.'

Cyclocross bikes, are somewhat race specific and sacrifice suspension for speed. Most cyclocross forks are going to absorb some of the vibration, but not much.

If your back is giving you trouble, I would go with something that does have front suspension like the XT you had.


When does a Marathon Plus tire (not) need replacing?

If this helps at all, I used a set of Marathon Plus tires on a cross-Canada tour last year (8200km), plus a bunch of commutting, totaling about 11,000km. I did not get any flats at any point, but by the end of that distance, the rear tire was pretty bald and I decided to stop using it.

Here's a picture of the tires around 10,000km, front tire on the left rear on the right. I consider the rear tire bald here since the part actually contacting the road has none of the factory tread remaining.

Three thoughts I'll share:

The Smart Guard is an extra layer of rubber between the road side and tube side of the tire, and depending on tire model it is one of a few non-black colors. I think the Marthon Plus is blue, and they do green on some tires, etc. Inspect your tire carefully in good lighting and see if you can see the colored middle layer anywhere, even a small patch. If so I would chuck the tire since that means you've broken through to the middle layer and the road side of the tire could start delaminating from there.
If your tire is bald but you can't see Smart Guard showing through, and you want to keep using it but are getting a lot of flats, check it for small embedded puncturing agents that may be stuck in the tire and puncturing your tubes repeatedly. E.g. on our tour, a couple of the other guys who were also using Marathon Pluses had a run of flats, i.e. one a day for several days. After careful inspection we found a couple of tiny wires, like human hair thickness and 2mm long, embedded in the tire that were almost invisible, but poking through to the inside and putting pinholes in the tubes. We eventually determined they were radial belt wires being picked up from the side of the highway from areas where transport trucks had had blowouts. You can get similar repeated slow punctures from tiny glass slivers.
If your tires look like mine (rear very worn and front quite new looking), resist the temptation to swap them between front and rear wheels. A worn tire is a greater candidate for blowouts and other major failures, which in turn are more likely to cause injury when they happen on the front wheel. If you don't want to replace both tires, then chuck the fully worn rear tire, move the partially worn front tire to the rear, and put a nice new tire on the front. More info on this here.

Hope that helps.


Removing bottom bracket from 79 peugeot frame

Usually one only needs to remove the left cup to service the bottom bracket. With Fench/Italian BBs the right cup is usually so tight it's not worth even trying (I personally attempted two times but never succeded EDIT. I also managed to damage a Park Tool BB remover, worth 15 quids...)

The left cup is always right threaded, in any case the lockring must have the same thread orientation of the cup.

As for the oversized lockring, I have had a good rate of success using adjustable pliers, just hold them tight enough so to avoid losing grip.

Finally, it's always worth repairing, or at least trying to!


I'll leave it to others to post a full answer, but I found this page about this very topic.


3 flats in 650 miles (1030 km) on hybrid bike. Tire pressure wrong?

Depending on your attentiveness while riding, the hazards in the area you ride in and a few other factors, that may be a reasonable amount of flats.  I know a few commuters in my area that expect roughly a flat a week in their roughly 100 mile weekly commute.  I've ridden with this particular pair of guys, however and found they have a tendency to shortcut through glass filled abandoned parking lots and the like, and they don't pick careful lines through that mess.

I will say this about flats, when you change a flat, you should always figure out why/how you got the flat.  If you don't, you'll just get the same flat again.  Pull the tube, keep it oriented, re-inflate it and figure out where the hole(s) are.  There are articles out there telling you where to look based on the placement of your tube holes and their configuration.  If you are getting repeated puncture flats from objects, you may consider switching to more puncture resistant tires.  Keep in mind more expensive does not mean more durable.  I've bought ultralight and expensive race tires before that didn't make it 13 miles around a loop before picking up 3 punctures from gravel that wasn't even that sharp.  I ended up switching to a much heavier but more puncture resistant tire that was 30% cheaper and hasn't had any punctures since.  I don't race, so that works fine for me.

If your awareness doesn't keep you out of glass patches and the like (or they are just unavoidable in your area, I am pointing at you Honolulu) and you get repeated puncture flats, you may also consider switching to a tubeless setup with juice in your tires to minimize the impact of these.


How to tell if a tire should be replaced?

A tire's job is to (not a complete list):

Stay attached to the rim
Protect the tube from damage
Contain the pressure inside the tube (this is why the pressure rating is on the tire and not the tube)
Provide a good connection to the ground

Tubeless tires also do the job of the tube.

The tube's job is to:

Hold air

In the drawing below you have a "Clincher" tire.

A simple guide on the essentials of wheels, rims, and tyres

You have two different problems.

Your tire is badly oxidized which compromises it's ability to do all four of the things listed above. You need to replace the tire.
Your tube is leaking air. This has nothing to do with the condition of the tire. You need to find the leak and replace or repair the tube.


Replaced faulty Shimano twist shifter but front derailleur still won't catch 3rd

That bike, and many similar lower-end bikes, comes with a clamp on derailleur, so the steps to troubleshoot your problem are:

Pivots do get dirty; give it a thorough cleaning with degreaser and then drop a few drops of chain lube on the pivots. While you are doing this, dial all the barrel adjusters back to their beginning positions.
Check the derailleur cage and make sure it is not bent.
Make sure the derailleur is mounted to the frame properly. The cage should be exactly parallel to the chain rings, and it should be placed low enough on the frame that the teeth of the largest cog barely clear the bottom of the cage.
With the cable and chain loose, ensure that the derailleur cage moves freely by hand. You can take this chance to begin to adjust the limit screws. Start with the low side, making sure it easily comes to rest to properly shift to the small ring when there is no tension on the cable. At this point it should be clear whether or not the derailleur is functioning properly.
With the cable housings detached from the guides Attempt to move the derailleur by gently pulling the cable by hand near the shifters. If this works the problem is likely in your shifters, or with friction in the cable housings. If you can shift it by hand, this is a good time to start to dial in the high limit adjustment.
If you make it this far, adjust the cable tension and dial in the shifting with the barrel adjusters.

My experience with that particular bike is that the derailleur is frequently mounted high, is easily bent, and notoriously difficult to keep in adjustment.


There are many available.  Here is one example: http://www.ebikestop.com/axiom_cascade_frame_pack_black-BG6638.php

Attaches to the seat tube and the top tube, providing a triangular storage space.  This one also is padded to aid with portaging (if you have a big enough triangle).

I know some people who tour with home-made frame bags that take up the entire triangle.

These bags are a great idea because they keep your load close to your center of gravity.


What is the max weight a standard bycycle would take?

178kg would put significant strain on most off the shelf bicycles. Most critical parts would be wheels, bottom bracket, crank set, and suspension if any.

I would suggest that you go to your local bike shop and have custom assembled bicycle for you with:

wheels 26" with at least 36 spokes, best quality double walled rims, best quality spokes and good wheel builder
robust steel frame with no suspension
wide tires
bottom bracket and crank set with external bearings like Hollowtech II, or better


Is it okay to true (align) a wheel with a missing spoke?

No, you cannot true the wheel with a spoke missing - at least not as a permanent solution. I'd only do this to get home or to a bike shop if it was not a long ride.

Remember that spokes alternate coming from the drive (right) and non-drive side (left) of the hub, and a properly trued wheel balances tension from spokes from either side.

If you have a drive side spoke missing the two non drive side spokes on either side of its position will pull the rim toward the left, you would have to slacken these spokes because they are not pulling against the missing spoke. This is going to cause tension imbalances in the wheel which will stress other spokes and accelerate their failure.


Certain manufacturers sell different tires for front and back and I have run different tires on front and back on multiple bikes when one tire is worn or punctured and needed to be replaced, but the other tire still has tread/life.  Mixing brands isn't an issue other than one tire wearing faster than the other one.
It shouldn't matter which tire goes where, but judging at the rate that my tires wear, put the newer tire on the back since it will wear faster than the front tire. I usually move the older tire to the front since it will wear slower and if there are punctures caused by the age of the tire, it is easier to replace a front tire than a back..


How to clean and brighten reflective wall tires

Hit the tires with a bush and some concentrated soap.
In the dark shine a light on them and you would be surprised how much they shine even if they look dirty.
Once you scuff em up bad then just time for new tires.


Tools and spares needed to repair a chain on the road

Replacing your chain at regular intervals is by far the best maintenance money you can spend on a bike. Generally what goes wrong with a chain is a "stuck link" and
the chain tool you have can fix that. Either by slightly tweaking the pin to loosen the link or by taking the link out altogether. If you do need to take a link or two out, avoid attempting to use the big/big gears. Generally there is no reason to carry a complete spare chain, only enough stuff to remove a link or two
and put the chain back together.

Some chains require special replacement pins. Check with the manufacturer. Exactly what's required varies between 9,10,and 11 speed chains.

For chains that have quick links, the quick links can break. Carry a spare quick link. You can use this to make repairs quick and simple. You can have more than one quick link in a chain w/o problems.

For the new narrower chains, I am not confident about reseting existing pins using any chain tool that you can carry on a bike. This is why I only use chains that have a reusable quicklink.

I'd think about switching to a chain like this in your case. Makes any on road repairs much simpler. However, I don't know of any 11 spd chain links that are
reusable.

I've done a bit more reading on 11 spd chains and I would definitely add a few spare used master links to your kit. KMC makes them and from what I read the old school method of pushing the pin back in just not safe with the very thin plates used to get chains narrow enough for 11 spd. KMC claims their quick links will work with any 11 speed chain.


What type of brakes is least subject to failure in the winter?

Like the other answers, disc brakes are the only way to go if you plan on your brakes getting wet at all. After riding disc brakes for a while now, I will never go back, even in good conditions. I would also really recommend hydraulic disc brakes over mechanical ones, especially in poor conditions. With hydraulic brakes, you don't have to pull as hard to get the same amount of stopping power.


Are small radially laced motor hub wheels like Swytch trash?

This is a poor design that can work due to several properties:

On an electric bike, only part of the load is supplied by the motor. Most of the load is still actually supplied by the pedals. Thus, this should be not considered a primary motive propulsion device but rather a hill assist device.

An electric assist provides continuous torque. In contrast, the cyclist pedaling provides an oscillating torque. So if you ride 50 meters upwards on a 8% grade hill (625 meters linearly), the cranks would probably rotate about 140 times, meaning there's 280 power strokes and thus 280 load cycles. However, an electric assist would create only one load cycle in this hill.

The hub flanges are large. The larger the flange, the better the system is able to withstand torque. Optimally the spoke pattern should probably be 1-cross or 2-cross, in which case there is already a large effective "torque arm" to create the torque. On a radial wheel, the effective "torque arm" is created by the hub flange rotation with respect to the wheel rim. Creating such "torque arm" on radial wheels of course affects the tensions of all spokes (tightening them), so I would expect the wheel to fail in a very short amount of time, unless stress relieved. However, stress relieving the spokes could make them withstand the amount of time it takes the buyer of the "electrification kit" to realize the kit might not be such a good idea and purchasing the electric Brompton from official source would be a far better idea.

Thus, the design is marginal. It will probably last few thousand kilometers. It could last few tens of thousands of kilometers if using the lowest assist level and if the weight of the cyclist is low.
I wouldn't buy it.


That model number you provided does not end in the numeral "1". Rather, it is the letter "I" which stands for "interactive glide." That means that although it is of the Shimano HG model series it is only compatible with IG chain. IG chain has an external width of 7.1mm compared to HG's 6.6mm.

Your KMC Z8S chain has a outside width of 7.1mm. It is therefore in the family of Shimano IG compatible chains along with KMC's Z51 and Z72. What you may try is adjusting your B tension screw on your rear derailleur. Adjust it so that your upper carriage/gear pulley is close to the low gear sprocket but not hitting it. Doing so will improve chain to tooth engagement.

Also, check that your derailleur/gear hanger is not bent and that your derailleur limit screws are properly set.

If this doesn't work then your sprockets may be worn despite appearances. I have encountered freewheels/cassettes that appeared un-worn but exhibited the slipping you mention even after installing a new chain. The problem was solved upon installation of a new cassette. Slipping sensation may also be caused by a worn or damaged hub body (aka, freehub) as the pawls fail to properly engage the freehub teeth. In such case it isn't the chain but the freehub itslef that is slipping but it can feel like a slipping chain.

Lastly, if your chainline is way off you may have chain rub or slipping front or rear. If you recently changed the bottom bracket, serviced your rear hub, or swapped sprockets within your cassette cluster check that all spacers were replaced properly. Also verify your new bottom bracket spline width and offsets match the old.


Freehub movement on Reynolds hub--is this OK?

I think what's going on in that video is either a slip fit endcap has partially slid off, or a threaded one is loose. If they're slip fit than of course it will all be fine once the wheel is back on the bike. If threaded, they should be re-tightened.


Sounds like your derailleur cable broke or got loose and so your derailleur is moving to its default outermost position, the smallest gear (assuming your shifter is labeled such that 6 is the highest gear).

You might be able to find where it's loose and retension it. More likely, you'll need a new derailleur cable. About five to ten Eurodollars.

However, in a situation where your bike toppled, you could have bent your derailleur hanger. It's worth just having the shop do the cable replacement and rear derailleur tuneup and realignment. It should be around half an hour of shop time labor.

Note: another scenario if you have index shifters  is that the crash yanked the derailleur with such force that it broke the index shifter internals such that they do nothing and the derailleur is reverting to default. Again, the shop should be able to tell. New shifters are only fifteen to thirty Eurodollars for the inexpensive lines.


Can I replace the front front derailleur with chain guide?

The simple test is just to remove the derailleur. Some of them have a screw holding the bottom of the cage together, in which case it's easy - just undo the clamp holding the derailleur to the seat tube, the cable clamp, then once it's loose undo that screw and wiggle it off the chain.

Without that cage screw you'll have to break the chain which requires either a quick link that can be undo by hand, or a special tool. Putting it back on afterwards is slightly more complex but quite doable for most people. If that works, you can then remove the cable and outer, and possibly the shifter (these days likely to be built into the brake lever so not removable).

But as Batman pointed out, the front derailleur is not the heavy part of a multi-speed setup. Most of the weight loss from a single-speed conversion is in losing the extra chain, cassette and rear derailleur, and the maintenance benefits also come mostly from not having to adjust the rear derailleur. So the total benefit is likely to be low. You might also lose a little weight by removing one of both of the extra chainrings, but again not every much.


Slick tires and Knobby tires vs Bumpy roads!

YES smoother tyres are better than knobblies for road usage.

Knobblies means your tyre's carcass is a little higher off the road, and if your knobs land on the corners of the bumps, then there's a lot more rubber between the compressed air and the edge.

Downside is knobbly tyres (tires) tend to be less thick between the bumps.  So if you hit the obstacle between tyre knobs, then there's less thickness.

Generally you want smoother tyres for on-road.  Commuter or touring type tyres tend to have more thickness, at the cost of more weight.  Racing tyres tend to be made thinner, for weight.

Also your cornering on smoother tyres feels better, because knobs tend to squirm sideways under load.

But the biggest thing is your technique.

don't go over bumps and into potholes, if you can avoid them
If you're riding up and down curbs/kerbs, stop it.
Unweight your saddle when going over bumps - get up on your hands and feet only
Clipless pedals are good for quick spontaneous last-second jumps, more-so when in the unweighted posture.


Does it make sense to switch to single chainring on an older mountain bike?

The more general form of the questions is: is it worth upgrading a bike vs buying a whole new bike?

In many cases it is not worth it. Individual upgraded components are compromised by remaining lower end ones. Full upgrading of components is as expensive as a new bike. The bike is still saddled with older technology (such as rim brakes).

However, if the point is to mess around wrenching on a bike, give it a new lease of life, the components to be replaced are worn out anyway, and the limitations are well understood; then that in fine. Especially so if the builder is prepared to spend some time on Craigslist and Ebay finding cheap serviceable parts.

[Full disclosure - I own a mountain bike with components spread over two decades.]


Preparing for a long distance ride - long term

You have more than enough time, so use it.

Start at 25km, increase distance by 10% per week.  This would mean just six months to 280km. Key thing is start slowly, don't over do it, because of your time frame, do less not more, if you take time off (more than a couple of weeks), drop back a bit. Plot a line on a calendar - from now at 25km to May next year at 280km, this is the easiest to sustained buildup. Plot another line, From November at 25km to May. Think to yourself this is the line you must no drop under. For most people, due to 'life' getting in the way of training the reality will be in between these lines.

Better to do 3 rides a week than one big one. Every few weeks have an easy week where you do maybe 1/2 to 2/3 of you previous week.

The biggest obstacles will be being short of time during the week, in which case maximise you training effort, but make sure you get at least one long ride a month in. Failing to get out over winter (depending where you live) can be a problem, indoor trainer, or cross training at gym and pool will get you though winter in good shape. Still try to get out on the bike if you can.


How can I stop my mudguards from rattling?

I think it's a problem that must be solved on a one-off basis, since there so many different fender/bike combinations.

First make sure the connections are really tight.  Often they work loose over time.  Then try to observe what's rattling.  Some heavy tape applied to points that tend to knock against the bike frame may help.  Different fenders that are stiffer and have more stays is another possibility.  In some cases you may simply want to cut off, eg, part of the front fender extending forward from the fork, as that area tends to be less well secured and vibrates quite a bit.  (Mine cracked at the fork and the front part fell off some years back, and I haven't missed it.)