What are the reasons for using a cradle with a handlebar mounted drybag? I am talking about things like the cradles that Salsa and Revelate make. The most obvious reason seems to be to keep the drybag away from cable and cable housings. However, on my particular bicycle, I have wide handlebars (Nitto Albatross) with full cable housing, and it doesn't seem like that's an issue for me. I've done test rides with a drybag strapped directly to my bars, and it seems fine. However,  before I head off on a tour, I'm wondering if there any other reasons I would want a cradle that I'm not thinking of.

Having now toured for two weeks using a dry bag strapped directly to my own handlebars, I can now sort of answer this question. I still haven't toured with a cradle, so I can't give a full side-by side comparison, but I can say that I spent two weeks riding without one and I didn't particularly miss having a crade. All of the comments by u02sgb in their answer seem potentially valid – I can imagine maybe it being more stable or easier to attach (edit: mostly easier to attach, stability was fine) – but those seem more nice-to-have than a must-have.

The main reason I can think of where it might become more of a must-have is if you were going to be on a multi-month tour, you might want one to prevent bag wear; I noticed some wear to my drybag where the straps went. Not a lot, the bag is far from worn out after two weeks, but it probably would wear out faster than a drybag would ordinarily. One could probably also mitigate that by getting a drybag that has reinforced tiedown points, or some other scheme to protect the bag from the strap (a wider strap, or a strap through a bit of used firehose perhaps).


Should I upgrade/rebuild an old rusty bike or get a new one? A couple days ago my friend gave me an old bike.

Much of the bike is very rusty although the frame and handlebar does not have as much rust.
I am not a bike expert and have been learning quite a bit about bikes on the internet since the day I received the bike. I looked it up on Google and found that it is worth somewhere around $200 and is pretty much something you can get at Walmart.

Since the bike is so broken down and rusty I thought of reusing the frame and getting everything else to make a new bike. My budget for the parts is about $200. I am planning on riding about 150 miles a week on the bike.

What I am asking is should I be at all concerned about the quality of the frame?

Or do you think I should save up for a pre-built bike?

Personally, I would save up for a decent bike in better condition. The cost of labor to overhaul a bike is substantial, and it's not really worth it if the bike components are crummy to start with. You may end up spending more in components and labor than getting a decent bike. There are frequently deals to be had on decent used bikes.


Rear wheel resistance and vibrations are driving me crazy I've recently purchased a new wheel set for my track bike. It's a Phil Wood High Flange laced to H + Son Archetype.

I've been traveling a bit and haven't really ridden them very long. I immediately set them up on my bike and rode them the following day on a 40 mile ride. Halfway through through my ride I started feeling a bit of resistance, as if someone was holding me back, causing me to use use more energy and slowing me down.

I pulled off, checked chain tension, alignment and wheel rub (no brake rub because I ride brakeless) but everything was fine. I've read on here of similar scenarios from other riders however, many said they were going a particular speed. Somewhere between 20-30mph. Mine is on and off, the resistance does pick up on elevated speeds but for the most part it holds me back.

Today I went for a ride, looked over the rear wheel especially and again, everything checked out totally fine. Though, it went straight into the same issues as before. Only on my way home my rear wheel actually somehow loosened and had major wheel rub. I pulled over and realigned the wheel and tightened. It didn't happen again.

If anyone can give some suggestions or opinions I'll really appreciate it. Cheers

Check if the bearings are worn. I know its new but it's worth checking. If there's no grease on the bearings, apply some grease on the bearings and install the wheel back. But before doing that, check if the bearings were screwed in too tight. if that doesn't make any sense to you, I apologize.


Torque Setting Of A Compression Nut Could somebody please help me as I am struggling to find the answer.
I have searched the internet but cannot find anything specific to my bike,apart from a manual which does not have that much information.
I purchased a second hand Boardman URB 8:9 hybrid bike. It's not the current model, but one from a couple of years ago.
It came packaged in a box, so the usual pedals, handlebars etc, needed to be refitted.
When I came to putting the handlebars back on, I noticed the compression plug/nut inside the steerer tube is loose. With the forks being made of carbon I am worried about tightening this nut without knowing the recommended torque.

The steerer-tube plug or bung has two functions:

Provide a backstop for tightening the stack;
Resist the crushing force on the steerer tube from the stem pinching it.

So the plug needs to be tightened just enough to serve the first function (for which some friction paste may help); this will naturally put it in a position to serve the second function.
It's also difficult to torque down hard on the plug, as there's nothing except friction against the steerer tube to hold the body in place as you tighten the bolt.


How to carry a step-through/mixte bike How can one carry a bike with a step-through/mixte frame effectively?-- In comparison, any diamond-frame bike is a breeze for me to shoulder regardless of weight (okay, carrying a 25+-kg roadster is not exactly enjoyable, but it can be done): I've tried carrying a "true" step-through frame (but never a mixte) and it seems that, no matter how I hold the thing, I feel like an idiot and become exhausted after only a couple of minutes.

Online, I haven't been able to find much actual info on how to do it despite loads of discussion about how diamond-frames are so much easier to carry. On Lovely Bicycle!, however, there is an explanation of doing this for different models of step-through bike, but unless the girl pictured in that post is a deadlift champion, I don't see how it's possible to hold those bikes for very long.

Find the centre of mass of your bike, which is usually just above the BB+downtube.

There are two strategies for carrying the bike, assuming that the bike does not have any heavy accessories such as pannier rack+bag, which would otherwise alter the centre of mass of the bike:

flat/downstairs: one hand go over the top tube, grab the down tube so that the bike naturally leaning forward. The seat should rest on to your shoulder. Your shoulder carry most of the bike's weight.
upstairs: reverse the bike, one hand on down tube (or chainstay for a very tight stairs) with the (back of the) seat resting on shoulder. Again, your shoulder should carry most of the weight of the bike.

Downstairs/Flat

Upstairs: as Criggie has suggested, carrying on your left (non-drive side to your body) would be cleaner (although my pants are usually black and my bike has a chain guard so I have no problem). I would like to note that if you choose this option, take care not to dirty your sleeve. Holding the seat tube is a little bit awkward, you could try to hold the crank and see if it fits your style. You can also use the other hand, holding the chainstay, to guide/stabilize the bike


How much does rider weight increase tire pressure? When a person sits on a bike, the air pressure in the tires must go up because of the additional weight. With 100 PSI in 700x23 tires on a riderless bike, what is the air pressure when a 100 lb rider is sitting on the bike? A 200 lb rider?

As a first approximation you could use zero.

But more accurately, with a 23mm tyre you probably have about 20mm diameter of air inside. A 700c wheel is ISO 622, so has an inner radius of 311mm. So your tube forms a torus with major radius 321 and minor radius 10mm. A litre is a cubic decimetre (a cube 1/10th of a metre or 10 cm on a side) so it's easier to use dm for this. So, major radius = 3.21dm, minor = 0.1dm.

  Volume of a toroid = 2 π² minor² major = 2 π² 0.1² 3.21  = 0.63 litres

Now, at 100psi with a 200lb rider the flattened area is 2 square inches, or 1290 mm². So we want the volume of a toroidal section having that flat area. Conveniently the section is an ellipse, so the area is π (major radius)(minor radius) (and a circle is πr² because both radii are the same). As a first approximation let's say that the minor axis is half the width of the tyre (so 10mm) and see what happens:

  a = π R r =>  R = a / π r = 1290 / 10π = 41mm

That seems a little on the short side, but it's vaguely plausible, so what's the volume? Unfortunately the volume of a toroidal section is a bit beyond my rusty calculus, so I'm going to cheat. A lot.

First, what arc does this represent?

  sine θ = 41/321 => θ = 0.0004 radians (about 7°)

That's about 3.5° each side of the centre of the flat spot.

How deep is it? Since sine X = x for small x, and we definitely have small x, if we go out 20.5mm from the centre of the flat spot we've got a right triangle 20.5mm on the long side. The short side is that times sine 3.5° as above:

  depth = 20.5 * (20.5 / 321) = 1/321 = 0.003mm
            = 0.00003dm (since we're using dm for volume calculations)

As you can see that's a pretty flat shape, so even a crude pyramidal approximation is not going to matter too much (if it's out by a factor of 5 or 10 it's not really going to matter, it's still going to be "roughly zero" as a fraction of the total volume above).

Conveniently we can express the volume of a pyramid as a factor of the area of the base:

  volume of a pyramid = 1/3 height * area of base

The area from above was 1290 mm², which we need to divide by 100² to get it in dm² for the volume calculations = 0.129 dm²

  volume lost = 1/3 * 0.00003 * 0.129 = 1.34e-6 litres

What fraction of the original volume is this?

  fractional change = lost volume / total volume = 1.34e-6 / 0.63
  = 2.12e-6

See, even if that's out by a factor of ten, we're still looking at a volume change of 10-5. So the pressure change will be about the same, a change of 1/1,000,000 the actual pressure.

If this was the XKCD guy's "What If" I'd now work out how fat you'd have to be to cause an appreciable change in tyre volume. But I'm not, so I shan't.


Disc brakes too tight after pad replacement I've just put new pads on shimano deore disc brakes for the first time.  I pushed the pistons right in until flush, popped in the new pads easily, but when I pull the lever the pads stay against the disc. It's a slight but continuous rub at the front, but the rear barely moves.
I'd recently flushed with worn-out pads, so I thought possibly there was too much oil. I pushed the pistons back in allowing excess to leave, but same problem.

I recently did a long drive with the bike on the back exposed to rain and salt which I don't think helped. Any suggestions?

Deore disc brakes (and most others) use a spring to apply pressure to the pads which helps the pistons and pads retract when you release the brakes (the primary return mechanism for the hydraulic system is a spring in the piston assembly in the lever, however as this only acts on the pistons the pad return spring is responsible for separating the pads from the rotor). Often a pad return spring will come with the new pads (an example listing from CRC) but if not you can reuse the old spring as long as it is undamaged.

If you don't recall installing the spring when you changed the pads it may have fallen out and gotten lost, or it remained in the caliper when you removed the old pads and is now sitting underneath the new pads. When installing the new pads for this style of brake the prongs of the spring should sit either side of the friction material and rest on the face of the metal backing plate closest to the rotor (~5:30 in the linked video shows the process). The holes for the retention pin should line up as well.


How to polish carbon frames? My carbon frame has some slight scratches and some black gunk around the seat stays. What is the best way to polish the frame to bring it back to its original appearance?

I was thinking of using a solvent to remove the black scuff marks and a 1200 wet-n-dry emory paper with water to gently polish the duco back, finishing it with a gentle buff and polish.

Someone here reckons the car polishing products are just as good.

Any thoughts on this please?

UPDATE: Yes I have tried the damp cloth trick already. No good once it dries.

Thanks

You have two options:

Using polishing compound WARNING: if this is your first time tinker with carbon fiber composite, I would recommend you to read up carefully, beside from my general guide in here.

a) Use sand paper to lightly sand down the scuff. Make sure you do not sand into the carbon fiber. The sanding would produce black powder if you make this mistake.

b) Apply polishing cream/grease to make the surface shiny, with a cloth.

Advantage: i) stress-free, ii) simple and quick iii) cheap

Disadvantage: i) might require you to re-apply the polishing compound ever 3-6 months.
Using epoxy (cold setting, Bisphenol-A-Diglycidylether + Triethylenetetramine)

Preparation: Epoxy resin and hardener, release film (or alternatively, electrical tape)

a) sand down lightly. Do not sand into the carbon fiber.

b) Tape around the tube for both ends of the fixing area, approximately 1.0 cm away from the sanded area.

c) Apply the epoxy. Do not smear the epoxy yet.

d) Apply release film/electrical tape and use pressure to smear the epoxy over the surface.

Advantage: i) gives a very shiny surface if done correctly, ii) permanent surface

Disadvantage: i) moderately difficult task, ii) expensive and arduous project


Do tube protectors increase rolling resistance or just add weight? I have been experiencing a lot of flats lately (proportional to the increase in time/distance I have been doing), so I am thinking of adding a tube protector (e.g., one of these) to each tire.

Will this alter rolling resistance or just add weight to the wheel? I'm not sure what goes into rolling resistance aside from tire material and pressure. I expect a slight slow-down, but I'm not sure what to expect. I'm willing to trade slower speed for the time fixing flats.

It likely depends a lot on your tire pressure.  For high-pressure tires the liner just adds to the stiffness of the tire and might actually reduce rolling resistance slightly.

For lower pressure tires, the liner must flex and, to a degree, slide against the tire and tube with every revolution, increasing internally dissipated energy and hence rolling resistance.  But the effect would be slight.

A better solution is to use Kevlar (or equivalent) belted tires.  These have about 10x the puncture resistance of standard tires, have negligible effect on rolling resistance, and are much easier to deal with than the separate liner.  But of course they're 30-50% more expensive, and hard to find in certain sizes.

(NB: Don't confuse "Kevlar belted" tires with "Kevlar bead" tires -- Kevlar bead is used in folding tires, some of which are Kevlar belted and some not.  And I personally find folding tires a PITA to install the first time -- though some people love them.)


Reoccurring Bent Axles, any reasons or upgrades? Earlier this month I had a issue with a broken axle.  It was the original that was sold with the bike and lasted around 5,000 miles.  I went to my LBS and bought a new axle (unbranded, labeled, etc, paid $13, came with cones, spacers, and hardware).  I did the install myself and had everything adjusted nicely.  The next time I rode it was on my commute to work, but I didn't get 4 miles into it when I found that I bent the axle.

I took the wheel to the shop but they wouldn't do anything about it since I didn't have them do the work.  However, I figured this was a fluke and asked them for a new axle and to true the wheel.  Once again I did the install of the axle and only got 15 miles out of it this time before bending it.  Before I got home I felt the wheel get stiff, but it stayed true.

The question is what will be a cause of bending 2 axles in 20 miles?

I think the guy at the shop said it was a cro-moly axle (while talking to another person today at the shop, these may not be), and he couldn't believe that I bent it.  If so, where would such an axle fall in the quality hierarchy?

Or is my hub toast?

While the wheel was being repaired, I swapped to a new original wheel for about 2 weeks.  I have not had any issues with it, but I wanted to keep it as new as possible.

Reading other questions I saw a comment that said not to use a hub where the bearing was catching.  I did have one in this wheel but I figured since it is a cheap wheel I would just burn it up and move on to a better one.  Besides, it has lasted 5k miles without issue to this point.

The bike in question is a 2008 Schwinn High Timber with Joytech freewheel hubs.  I do use a trailer with this bike using a Burley axle hitch.  While I had the hitch installed on both axles I bent, I did not have either trailer hooked up to them.

Something I would like to note is that when I removed the first bent axle (axle #2) that the cones on it had a wavy bearing track.  I didn't think too much of it, and I put them on axle #3.  Only having a few miles on them shouldn't have made a difference?

The reason for the bent axles is primarily due to your riding a bike with a freewheel. Freewheels (as opposed to a freehub) have a length of unsupported axle on the drive side of the bike that is vulnerable to bending. That is the primary reason why freehubs were invented. As the bike industry moved more and more gear sprockets (6, 7, 8) this meant a wider cog and longer unsupported length of axle. It is amazing how many cheap modern bikes (Schwinn sold out their name for use on low quality bikes long long ago) are still using freewheels which are an obsolete technology at this point. http://sheldonbrown.com/freewheels.html

Improperly adjusted or worn bearings are not considered a major factor in having a bent axle unless the bearings are very destroyed and the wheel is not working normally. Bent axles are due to load. So, you using a heavy trailer and being a larger than average rider, the axle is more likely to bend.

Get a strong well build wheel with a freehub. If you want an axle of CrMo then make sure you are getting it. There are OK inexpensive wheels for $40 so at $15 per axle replacement (excluding labour) it really makes more sense to not be replacing axles. Joytech is a cheap hub. Buy a good quality wheel that is worth >~$100 and you will save time and money in the long run.

I'm curious what you mean by "bearing was catching...just burn it up" That sounds like you may not be adjusting things properly. Maybe review some insructions on doing a hub overhaul or go down to your local recycle a bike shop for some hands on learning?

I'm also curious how you could tell specifically by the mile when your axle bent? Normally a bent axle is hard to notice unless the wheel is removed.

I find that rear wheel axles even of freehubs can be hard to keep straight. My old parallax hub with an 8spd freehub would always have a slight bend when I took it off to examine it and this resulted in uneven bearing wear. Probably due to me carrying very heavy trailer loads, passengers etc. North American bikes are often designed for sport rather than long term utility so even a tall person may be outside of the design for the bike. My solution was to get an old new XTR titanium axle that was laying around in a parts bin at a shop I did business with. Since then my rear wheel hub has stayed well adjusted :-)


Luggage rack attachments for laptops? So, while out riding my bike, I really dislike having a backpack on.  I have a trek luggage rack on my bicycle and would love to find something that could attach to it, capable of holding a 17" laptop, preferably in a hard case, with padding.  I would really hate to lose the laptop (or its drive stability) to a fall/crash or even just the basic road vibrations and bumps...

Has anyone seen a product like this, or potentially know a good way to build something like this? :)

Your best bet for weatherproof and crash worthiness is going to be a pelican case. They have a whole series of cases for laptops.
http://www.pelican.ca/case_group_search.php?CaseGroup=Laptop

I've personally taken a 'hardback' case on a paddling trip and it held up great. Many pelican products also have a warranty against failure as well so if the product does leak you've at least got a new case and a replacement laptop.

If you get one of their other cases you can also lock the case which will assist in keeping it secure from a thief. Yeah it's not going to stop a determined person but at the least it will give you time to realize and change any vital personal information.

Past that make sure you backup your data with something like Mozy.com. At some point you'll have a drive failure no matter what.


Waterproof spray or waterproof pannier cover? Does anyone have experience with either waterproofing panniers with a waterproof spray or using waterproof covers for panniers? Which one was best?

I don't want to invest in waterproof panniers as I will be using dry bags anyway but it would be nice to see some repellent action going on.

I've personally never seen or heard of a waterproof spray that will protect against soaking. Water hitting the material might run off fairly well, but a continuous rain soaks it so much that water will just seep through. That might not be a problem for commuting, but I'm assuming that if you're going through the extra step of double water-proofing, you're probably touring. If you're touring, you're almost certainly going to be stuck riding in the rain for an extended period of time at some point.

Waterproof covers are ok. The problem is that they don't completely cover the pannier since they can't wrap around the mounting hardware. The back of the pannier will get wet. If there's enough rain, it'll get wet enough to soak through to what's inside. Another problem with covers, and this is the part that I like the least about them, is that it's just one more thing that you have to carry around. I'm not necessarily a weight-weenie, but I am a space-weenie and covers take up a fair amount of it.

Personally, I'd recommend skipping the dry bags (again, they just take up extra space) and getting fully waterproof roll-top panniers like the ones made by Ortlieb, Axiom, or Vaude. These bags will stand up to a freaking monsoon without any worry of water getting inside. The only real water related problem that you're likely to run into is that humidity can build up and condense inside the bags. But you're not talking about a huge amount of water there, certainly less than you would if you were caught in a downpour with a bag that wasn't waterproof to begin with.


Is there an improvement braking from the hoods from Shimano Sora 3500 to Sora R3000? I'm struggling to brake from the hoods on my first drop handlebar second hand bike although braking from the drops is fine. I read on this site somewhere that older Shimano Sora ergonomics were particularly difficult to brake from the hoods due to the pivot position. I don't have anything to compare my bike to (my local bike shops are not keen on people popping in and handling their bikes right now) but the levers do feel very badly designed as far as braking from the hoods is concerned. I will probably upgrade the brake callipers (from Tektro Mira) anyway but was wondering if upgrading the levers would also be worth it.
So my question is does anyone know if there is a significant improvement braking from the hoods between the Sora 3500 levers and the Sora R3000?
Thanks.

The R3000 levers have the shifting cables routed under the bar tape as opposed to coming out the sides on the older 3500 levers. If you care for the esthetics then that might be another reason to upgrade.  I'm not sure if the  braking performance actually changed as I don't have older Sora to compare to, but the R3000 levers in my experience seem to offer good braking performance from the hoods. The design of the R3000 levers is similar to the other higher tier models (tiagra, 105, etc) so I assume that the braking performance would be the same as those, assuming the brakes at the other end of the cables were also of the same quality.


Heavy bike lock mount on a carbon frame I have a foldable Abus Bordo 6500 which weights around 1.7kg. It came with a sturdy, rubber based case that can be mounted using bottle cage mounts.

Is this OK to do so on a carbon frame, or does it open up risk? The bike in question has 2x bottle mounts and I was hoping to put this on the seat tube.

At the moment I am chucking it in my backpack, but a bike mounted solution might be a little neater for days I don't have my pack.

(I did search but most questions on this topic relate to pressure clamps for D locks whereas my issue is a bottle mount.)

Thanks

In general strapping 1.7 kg of mass to a CFC frame is not a problem. CFC frames are actually quite robust. However, I would be concerned about attaching the case to water bottle mounts. Water bottle mounts, brake mounts etc on CFC frames are constructed with an aluminum insert epoxied in a hole in the CFC. These can work loose if subjected to too much cyclic stress.

This Hambini YouTube video explains how the inserts work (and how to fix them.

If the case comes with straps, I'd use those instead. Put tape on the frame where the case and straps touch it to stop paint being worn off by movement of the case.


How to lubricate cables? What is the best way to lubricate gear and brake cables in their tubular housings? Up until now, I've used CRC/WD-40 with an extension tube and attempted to squirt the lubricant into the tube housings. However, I suspect that this is fairly ineffective because 1. WD-40 is not a great lubricant (judging by the other Q+A on this site), and 2. the lubrication doesn't travel very far into the tubes.

So what is a good way of doing this?

As many cable manufacturers recommend, modern cables+housings are designed to not be lubricated.

So, if you have modern cables, I'd probably avoid lubricating the cables period.


Why participate in an organized century ride when I can ride the route on my own? I have never ridden a century ride before. This June, a friend and I plan to ride our first: The Montauk Century Ride. But I'm wondering, why should we commit to paying $100+ to ride this route in relatively heavy bike traffic, from a starting point not chosen by us, on a day that could be rainy for all we know? Why not ride the route on a day chosen by us? It seems to me riding on our own might provide a more convenient experience and more meaningful challenge.

What am I missing here?

Details depend on the ride, but usually organized rides provide things that you'd have to provide yourself. This one appears to provide a lot. This is covered by the catchall term "support", as in a supported ride.

The support that everyone enjoys is the food and drink along the way ("The Best Rest Stops") - scroll down on the page you linked, and you'll see that in this case it's a lot better than just a powerbar and a refill for your bottle. It looks like there's even food, beer, showers, and massages after the ride!

Support generally also includes some kind of assistance in case of breakdowns. Presumably you can fix flats, but say your tire is too damaged, or some component on your bike breaks. At the very least, you can get a ride in a support vehicle - and they might be able to help you get back on the road in some cases too. There's some about the S.A.G. (support and gear) service on their "ride day" page. They can also just give you a ride if a century turns out to be too much for you to handle.

Of course, another part of the appeal of rides like this is the "relatively heavy bike traffic". Some people like riding with plenty of cyclists on the road, and perhaps to hang around with after. And you don't have to worry about getting lost, or being visible to drivers.

So the supported ride will be a very different experience. Think of it as the challenge of riding a century without any details to worry about, and a bit of a party along the way and at the end. If you know you can handle the distance self-supported, don't care about riding with others, and it's more convenient to ride on your own, go for it. But if you go for the supported ride, your money isn't just disappearing into thin air.


Does "Carbon & Aluminium" really mean cheap plastic coated aluminium? I'm looking to replace the suspension fork on my MTB (which has blown a seal) with a rigid fork now that I'm exclusively commuting in the city. During my research I came across the
MOSSO 26" MTB Carbon & Aluminium Rigid Straight Fork on eBay, one of the cheapest "carbon" forks in this category at only 80 bucks.

What's the catch? Which parts are are aluminium vs carbon? How do they compare with pure carbon or pure aluminium? Is this just a gimmick to make aluminium forks look cool by coating them in purely cosmetic textured plastic?

No, in this case it means that the steerer tube is alloy, but the fork blades are carbon fiber. About the only products where you may see a layer of carbon over an aluminum core are stems, which is usually to make a cheap stem to match a good quality carbon handlebar.


is a 29er a good fit for a 5'9 height? I'm a 5'9.5 and I use a 26er gt and I don't feel that comfortable as it feels so small. I've also tried a 27.5 merida, it was an improvement but I can't still quite grasp that same feeling when you were a kid and bikes were huge. I feel a 29er would be better for what I'm craving for, but since I've been hearing about 29ers being sluggish, for a guy who loves single tracks, would buying a 29er which is slightly more expensive a choice to regret?

BTW I live in a city where there are limited bike shops, and they don't give test rides. So please help me. I don't want to spend my budget on something I really want and then regret it. An answer from someone who already had or have a 29er would be great, but anyone would be appreciated.

I would say it depends on your riding style and the geometry of the specific bike you are looking at.  29'r is definitely not to big for you (I am 5'10" and my 29'rs are just fine).  However, there are reasons that a lot of all mountain, freeride and almost all downhill rigs are still 26".  29'rs are less suited for highly technical riding, but much better suited for cross country and trail riding.  As always, tailor your bicycle choice to your riding style.

If you are into flowy single track and aren't hitting drops, ripping through rock gardens and generally abusing the landscape with your rig, then 29" is probably a better choice for you (with the right size frame).


I bought a used 20 inch bmx bike from bike shop but no one has any idea of the brand Could someone help me narrow this down?

I bought a new-used bike from local bike shop in Sacramento, California, USA. I do not know what brand it is and so were the bike shop.

There are no stickers because the bike was painted. The only things is the head tube logo which is engraved into the bike, or it has a 3D effect because it pops out.  Not sure what that would be called.  It looks like a giant logo but instead of the wave go through it side to side.   Iimagine if you just turned it to where it was up and down if that makes any sense.

The bottom bracket is sealed as well as in the neck.  I would greatly appreciate if someone could help me identify this frame.

Verde BMX at http://verdebmx.com/completes/

They appear to be based in Columbus, Ohio, USA.

Method:

I did a google image search for "BMX logo leaf" because it looks like a leaf to me
One of the images is this, which looks kind of similar
Following the link to their web site gave me this answer


Front derailleur won't spring back to lower gears The front derailleur on my mountainbike sometimes gets stuck in high gears. When this happens and I want to shift down I can nudge it a bit with my foot and it will spring back to the lower gear.

I think the spring is still strong enough because just a small nudge is enough. I haven't been fiddling with the two adjuster screws, and -as I said- if I nudge the derailleur after shifting it jumps to the correct position. The issue seems to be the (admittedly pretty large) amount of gunk that has gotten stuck in the derailleur over the years. I tried applying some WD-40 to the moving parts but two small applications have not really helped remove the gunk. Is this still the way to go or is there a better way to get the gunk out without completely removing the derailleur (which I -for now- am too lazy to do).

This question deals with a similar problem, but it hasn't moved beyond the diagnosis part (which I have already done I think).

[update:]

I tried liberally applying WD-40 a few times over the course of a week, including some (aided by hand on the derailleur) shifting after each application. This mostly removed the issue when shifting from 3 to 2, but 2 to 1 remained. Today I went to my local car-cleaning station and applied a high-pressure hose to the derailleur. This removed all the visible gunk. I applied some oil,  now shifting is as smooth as can be given the state of my chain and chainrings.

If you believe you have diagnosed the problem then a clean and a service should be all that is required. You don't have to remove the FD.

WD-40 will not displace mud effectively. I would:

use a hose with a decent amount of pressure to remove the gunk, wait for it to dry. (be careful not to spray around the bottom bracket)
apply WD-40 to any moving parts on the derailleur but focus on the pivot points to remove old lube.
once the WD-40 has evaporated apply some decent chain lube to the pivots.

If this doesn't fix the problem and the cable is moving freely the derailleur may be bent or the spring has lost the required tension.


Is the lack of activation in sore calves indicative of a poor stroke technique? I know this is a funnily named question, but please bear with me.

The pain was new.

My calves were incredibly sore - it was painful to walk (Likely owing as I had to walk up stairs - I probably did more than 10 stories pacing a coworker literally half my weight among other issues.  I'm heavy.)

I couldn't rotate on my heels during my stride at all.

Despite this, my cycling was just fine.  I didn't feel my calves nearly as much as when I tried to stand up and walk!

How much should I be using my calves during my stroke?  I do have straps on my pedals.  Does the fact that they didn't hurt when I was making my normal cadence suggest I'm not using my calves as much as a cyclist should?

Thanks!

Basing workload or technique on soreness is a poor indicator of what is going on. You could have bad pedaling technique and never feel it or have great technique with no fitness and feel sore right away.

It's likely that you are not using your calf muscles as much when you cycle as when you do stairs. Stair running is a great way to train most of the muscles in the leg, and the extension/flexion coming from the edge of the stair is what causes your calves to be sore later. While I don't have any professional experience to back this up, I believe that cycling doesn't quite put your foot through the same range of motion, thereby activating the calf less(I suppose you could point your foot up and down more, but that's bad form).

What you are likely seeing is a comparison between two activities that use similar muscle groups in different levels. Example: pulling up on a pedal (with cage or cleat) is different than simply lifting your leg up to the next stair since the pedal provides some resistance.

My recommendation: rest it for a bit, maybe a day or two and then do both activities moderately and see if you notice any pain. If you do, consult a physician about it.


Just installed a new chain but it took me 4 tries, is it safe? I just installed a new Shimano 105 11sp chain on my bike using a park tool chain tool to put in the pin. But I screwed it up 3 times . After each time, I popped out the pin and used a new pin (ended up using 4 pins). Is it safe?

I only ask because I didn't know if by pushing so many pins through the link I may have opened the link hole too much or something.

On the 4th time, I pushed the pin a little too much so the link was tight, so I rotated the chain tool around and gave it a 1/32 turn to push it back a quarter-hair.

If you must know how the hell I did it wrong so many times:

time 1: Inserted the pin from wrong direction & and it was outside one of the jocky wheel tabs
time 2: outside one of the jocky wheel tabs
time 3: outside one of the jocky wheel tabs (yep, it was early and I seriously just popped out the pin and put a new one without fixing it)

You should never break the chain at the connecting pin. Once a connecting pin is in there, it should not be removed.

Removing a regular rivet enlarges the holes in the chain plates slightly. A connecting pin has a slightly greater diameter than a regular rivet so it fits properly. When you push out the connecting pin the holes get enlarged slightly again, so now a new connecting ping is slightly too small.

So you have weakened the chain and run a increased risk of breaking it. You'll have to decide if you want to take on that risk. Personally, I would fix the chain for peace of mind.

If you want to fix it you have a couple of choices:

Replace the damaged chain links with new links from the small length of chain left over when you shortened the new chain, using two new connecting pins, and being extra careful to not screw it up this time.
Replace the damaged outer chain links with a Shimano Quick Link. Beware that most quick links are one-time use so make sure the chain is routed properly before completing installation.

I recommend #2

BTW, if you threaded the chain through the derailleur cage incorrectly, you can remove one cage side plate instead of re-breaking the chain.


Metal part of the pedal is coming off I noticed that screws connecting the metal part of the pedal are loose (I don't know the proper name for the metal part). I would like to screw them in but there's a piece of plastic that is in the way. How should I go about this (I don't want to yank the plastic part off the pedal). Here the picture:

I believe you will have to remove the reflector to get to the screws and there doesn't seem to be a non-destructive way. The mounts for the reflectors look like they are designed as one-way plugs. You could drill holes into the reflector to get to the screws without removing the reflector - which would be difficult to put back on. Even if you get this screwed back together, this is not going to last: the plastic is too weak to withstand the forces exercised from the metal plate when you stand on it.

I'm not sure this is worth the trouble. These are cheap pedals for which you can buy replacements on Ebay for under $€£ 10 from China including shipping.


What to get for my second saddle? I am a 16mi/day commuter and have been for the last two years.  When I bought my bike the first thing I replaced was the warn stock saddle with one of those "couch on a stick" models.  Say what you will, I put over 3300 miles on that saddle before the rails broke.

I now need a new saddle.  The LBS whats to sell me a $70 leather one that is frankly out of my price range. (I bought the whole bike for $50).  What is a good second saddle that will hold up to an admittedly rough commute, be comfortable and not break the bank?

Update:

The bike is a Alta Mongoose frame with 1.5" road tires. During the summer I ride in padded bike shorts, winters are often in rain gear.  Once a month or so I need to ride in slacks and dress shoes when I have a meeting downtown. I also take it out for an occasional weekend ride.

An older picture, I have since added fenders, new tires, and a better rack:

Product req questions are now Off Topic.

So you need to figure out what you want from your new saddle.

Start by measuring the width of your existing saddle, right where your sit-bones make contact.  Then use the cardboard or rice-sack method to measure your physical anatomy.    This will give you a number in millimetres.

Then look at the general shape of your old saddle - is it pointy?  Do the sides flare out late or early?  You either want a saddle that matches the overall shape, or tweaks any area that you feel could be better.

A new saddle is a chance for you to try a slotted design in the middle, should you suffer from numbness.

Finally the padding and covering are important too - your old saddle will probably not be worn out given it was a rail that broke.  So squish it with your thumb and try to gauge the thickness.   The covering is 90% likely to be some kind of vinyl or plastic.  If you like it, duplicate that.  If you don't like it, consider what else is available.

Now you say your bike only cost you $50 of your currency.  There's an implicit "...so I don't want to spend much money on it" and I disagree with that.

The saddle is one of the three contact points between you and the bike, with the pedals/feet and bars/hands being the others.   I'd have no problem buying some good shoes or pedals or bar grips for a bike.

Saddles are generally more difficult because they are quite hard to trial.  Some cities in the world have saddle libraries where you can hire a saddle for a month for a small fee, ride it, and then swap it for another one.

Leather saddles are even harder to trial, because they conform to the rider over time.  So they're somewhat like 10 pin bowling shoes.

Remember, any part can be removed from the bike and used elsewhere, so a nice saddle can be swapped onward if you break the bike.

Also ask around some other cycling coworkers, or check your city for a bike cooperative.  I have a number of spare saddles that I'll never use, which have turned up from bike teardowns or clearance sales.


Is it harder to ride a comfort bike on a paved trail than a hybrid? If I am on a "normal" paved by trail, hills, and straights, not mountains, sunny weather, and I have two bikes, a comfort bike and a hybrid. Is one harder to ride than the other?  The distance will be about 10 miles, paved, mostly flat trail.

One reason I ask is that if two people ride together and one is on a comfort, the other on a hybrid, if the comfort is hard to pedal, ride, etc., I would never be able to stay together (I would have the hybrid.)

For the sake of argument, both are higher quality bikes, not big box.  Is there some reason a comfort bike is inherently harder to pedal?

This is an example of what I saw:

https://www.performancebike.com/shop/bikes-frames/path-pavement-bikes/comfort-bikes/tuesday-bikes-march-7-womens-pavement-bike-31-7312

and,

https://www.performancebike.com/shop/bikes-frames/path-pavement-bikes/comfort-bikes

"Beach Cruiser" was also a term used.

'Comfort' and 'hybrid' are not particually specific terms. Let's assume:

Comfort bike means a bike with an upright riding position - the rider's back is nearly vertical. Handlebars are high and relatively close to the rider.

Hybrid means a cross between a road and mountain bike rider's back 45-30 degrees from vertical. Bars far enough forward so that riders arms are nearly straight.

(Almost) all other things equal: wheel diameter, mass, tire width and pressure, the more upright riding position of the comfort bike makes it harder for the rider to apply power to the crank, hence it will be harder to ride at the same pace as the hybrid. The comfort bike will likely have a lower gear ratio range to accommodate the lower possible power.


How to perform a long-distance bunny-hop? When I need to clear a missing pothole or a slippery section of the trail, I try to make the hop as long-distance as possible. The result is that, unlike when hopping onto something elevated, now I push the bike forward while in the air in order to "place" it as far as possible forward. The drawback is that I am getting closer to falling off the back of the bike.

Is this smart? What other techniques exist for jumping the furthest at fixed approach speed?

Some points.

If you bunny hop by getting both wheels to leave the ground at the same, the rear wheel has to jump the length of the obstacle plus the length of the bike to clear the obstacle.
A more modern, trialsy and BMX-y bunny hop is what is what is sometimes called an 'American bunnyhop'.  In this, the front is hauled up first, then the back as the front is being pushed down (tutorials are available on youtube, other video sharing sites are available).  This means the back wheel can leave the ground later, and so doesn't have to jump as far as in the point above.
Your time in the air is determined by your height, your distance traveled in that time is determined by your speed.  So jump higher while riding faster and you'll go further.  (And, potentially, crash harder.  Every silver lining has a cloud.)
When mountain biking, simply "unweighting" can often be enough to help an already rugged and quite probably suspended bike better cope with rough patches.  And if all else fails - just get the damn front up and over!


Tactics for riding in strong winds I happen to live in a windy climate. I often find myself riding against strong headwinds and sudden gusts seemingly coming from all directions at once.

What are your tactics for riding in such conditions?

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

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

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

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

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

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

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

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


Time trial carbon frame scratches. Should I concern? While cleaning my time trial bike I've noticed many scratches in the frame. See pictures below.

My tire pressure is usually around 100 psi, depending on the weather conditions or circuit. My wheels are the following: https://9thwave-cycling.com/product/road-sl50-wheels/

Should I be concerned? What can I do?
Thanks in advance.

Looks like you have had significant tire rub on the frame for a while. I'm surprised you did not notice the friction and drag.

If the abrasion is not all the way through the paint (the worst seems to be into the light colored primer) then you are probably OK in terms of physical damage. I might still be concerned about the possibility of heat damage, but if there does not seem to be heat damage to the paint the CFC epoxy is probably OK.

Presumably the bike did not always suffer from tire rub. Did you change to a wider tire? Have the dropouts been damaged? Looking at this image of a P2 on Cervelo's website  I'd say there is something significantly amiss that has let the wheel shift forward. [Edit: better picture provided by OP shows that the wheel has not shifted.]


Broken shifter cable in Shimano Ultegra 6600 10-speed shifter I broke my rear derailleur cable right at the shifter. These are Shimano Ultegra STI shifters from a 2008 Giant TCR C2 (I think they're Shimano 6600). I'm assuming that the cable head and frayed wire are stuck inside the shifter, but I can't see how to access them.

I have seen various online videos, such as How To Replace Shift Cables In STI Shifters/Brifters (Combined Brake/Shifters). However, I can see right through the shifter and don't see the end bit. I first shift into the easiest (biggest) ring. The shifter then only shifts 4 clicks into smaller rings, but I would expect 9 clicks (since this is a 10-speed shifter).

Does anyone have any ideas, based off the following images? I see a few screws that I could try to remove, but am wary about disassembling the shifter.

This is fixable, but may be any level of difficulty.   It depends on how the strands of cable have moved and whether the cable head is caught.

Given its your rear shifter, its on the Right side of the bars, and there's a port for the cable outer to seat in on the left side.   When you shift down (to an easier gear/bigger rear cog), the whole brake lever rotates, and holding the lever there will show the access hole on the right/outboard side.

Moving only the upshift lever (the smaller one behind the brake lever) won't show the hole.

Your next task is to hold the lever across, and try to make the cable head fall out the right hand side access hole, by hook or by crook.   The head may not fit through the hole sideways, it may have to come through flat-face first.

Some ideas to help manipulate it...

More Light!  You need to see, so use at least two bright lights.  I have a pair of 200W desk lamps over my bench, which helps avoid shadows.
A thin and stiff wire in the left side port to push the head from underneath
A tiny magnet - depends if the head is steel, or if the cable has enough steel to react to a magnet.
A tiny sharp pick to help manipulate whatever you can see through the holes.
Slack off the clamping bolt to rotate the lever hood, get gravity on your side
Undo the stem to let the bars rotate, again for gravity
Untape the bars, get the whole shifter body off the bars for easier access.

You might try flushing the mech with light degreaser, in case theres a blop of grease holding it down.  However this might have the opposite effect

If that doesn't work, you're probably up for disassembly.   Since Shimano shifters are not intended to be serviceable, this can ruin the shifter if done wrong.  There's no shame taking the part to a good LBS bike shop for repair.

Have a read of https://bicycles.stackexchange.com/a/35662/19705  where I did a similar recovery on my 7 speed RSX shifter.

There was a useful video at

Gear cables should be replaced whenever shifting starts feeling "a bit weird" or every 10,000 km of road riding, or 5000 km of off-road.  It would have been impossible to see this cable fraying in place during inspection though.   You should probably replace the left-side cable too, and check the brake cables as well.

Sadly 6600 and 6700 and 5700 shifters were known for munching through cables quite quickly.  If it were my bike, I'd replace the shift cables annually whether they need it or not.   Cables are cheap.


How hard is this climb and how long should i be taking? This was my first attempt at this route on my several year old Avanti Giro 1.0. Ive just started riding again after quite a few years and am h

https://www.mapmyrun.com/workout/3796895674

A common measure of fitness in the pro peloton is watts per kilogram, or how many watts of power can you generate per kilogram of body weight for a 1 hour effort. This is more or less a direct translation into your climbing prowess.

The "magic number" for pro racers is 6 watts per kilogram. I would say that for a recreational rider anything over 2 watts per kilogram is pretty good.

You can get some estimate of the power required for a climb via various online calculators. They are at best a good guess, but for climbs without headwinds at speed less than 20 kph, reasonably accurate.

These numbers will not be super accurate, but will give you some idea of what is typical.


Can I use a 6mm threaded bolt instead of a bleed valve for hydraulic brakes? I've accidentally lost the bleed valve in a front-brake "bleed gone wrong" afternoon and was wondering whether there's anything detrimental in just using a 6mm bolt instead for the time being?

Well you won't be able to bleed your brakes for one thing.  You can buy bleeder screws at auto parts stores.  I've never bought one, but 6 mm sounds like a normal size.  I'd check there.


Which cassette removal tool do I need? what cassette removal tool do I need for this cassette

Is it an FR-5 I need? Also I noticed it said 40NM on it so I'm guessing I need some sort of torque wrench to tighten it up?

FR-5, any Shimano one, basically any cassette lockring tool other than Campy (there's only 2 standards and Campy is much less common). You also need a chain whip. If you want to use a torque wrench then any that have 40nm or 30 ft-lb in their range will be fine, such as most common automotive ones. In that case you'll need a lockring tool with a square drive in back such as the ones made by Lifu or Pedros, or a 1" socket for the Park ones. Personally I only use torque wrenches on aluminum freehub bodies and even then it's a pretty minor concern. 40nm/30ft-lb is pretty tight. The best way I can describe it is as it's reaching full tightness, you'll typically feel one last firm click of the teeth of the lockring and cog engaging, such that it would be hard to imagine any unintended forces overcoming the thread preload and getting the teeth to disengage. That's tight enough.


Road bike front wheel question I was doing some maintenance on my road bike. I took the front wheel off, removed the quick release skewer from the wheel, set the wheel aside, and put a drop of tri-flow on the skewer to lubricate it.

When I returned to the wheel to reinstall the axle I knew the quick release goes on the left/non-drive side of the bike's fork due to previous pictures I have taken of the bike. However, when returning to the wheel I had set down, I cannot remember which side of the front wheel was the "left side".

My main concern is that while I have the quick release in the correct position relative to the fork, did I accidentally flip the orientation of the wheel? The bike has v-brakes so I cannot reference a disc to make sure I am returning the wheel to it's original orientation, and it has slick tires that do not have a "rotation/directional" arrow.

The only comparison I can make is that when looking down from a top view of the bike towards the center (right in between the spokes) on the hub the word "prowheel" reads from left to right in the middle of the rear wheel. So I installed the front wheel also to match the word "prowheel" reading from left to right.

Essentially I want to ask if it makes sense the way I returned the front wheel to the bike? Can you even put a front wheel with a slick tire and no disc brake restriction on "backwards"? Does my logic make sense with returning the wheel to match the wording on the front and back inner hubs?

Thanks in advance for your time, let me know if you need pictures to make what I am trying to describe more clear.

Joe

Update: I wanted to add a few pictures so I am making it more clear.

Thank you! One slight edit to my post is that the hub says "Chosen" not "prowheel."

Yes, here are pictures.

Picture 1 is a picture of the wheel and slick tire.

Picture 2 is the orientation of the wheel in which I perceive to be correct,
I put the quick release skewer into the front wheel with the handle to the left with the hub writing saying "chosen" reading from left to right when looking down at it.

Picture 3 is the wheel flipped 180 Degrees and installed and what I perceive to be incorrect, the quick release handle is still to the left but with the hub writing of chosen is reading right to left/upside down which I think could be the wheel on backward / to be incorrect.

Picture 4 matches the orientation seen in picture 2 with the rear wheel. It was my way of comparing the front wheel'S orientation to the rear's and seeing that chosen is written the same way from left to right when the front wheel is in this orientation.

Hope the pictures help! Let me know if I have it correct in picture 2 or if it still doesn't matter either way! Thank you.

The front wheel itself (for rim brakes) should be symmetric and can be installed both ways, unless you can find direction marks printed directly on its rim. The tires, however, can have recommended direction printed on them, which you should follow.

For fully slick tires both directions are equivalent. For tires with tiny tread it is not as important as it may seem, but you should still follow the rotation arrow printed on them in order to not look like a novice. For tires with aggressive tread the direction is important and, interestingly enough, the same tire often should be installed differently depending on whether it is on front or back wheel (then there are two marked rotation arrows on it).


Replacing one derailleur with another type I have an older bike (between 10 and 15 years old), which has a alivio derailleur. It's an 8 speed, and I just replaced the cassette, chain and crank set. I noticed that there was a large amount of play in my derailleur, so I reckoned it's time for a new one. Will this shimano acera derailleur fit instead of a new alivio one? They are quite a bit harder to find, and I'll just go for this if it's the easiest option.

Thanks!

EDIT:

I replaced it this afternoon and it worked perfectly; thanks for all the advice.

The derailleur you linked is compatible.

In general, Shimano shifters for 9 speeds or less for off-road series and 10 speed or less for road series are interchangeable if the mounting scheme fits. 7-speed cassette is narrower than 8-speed, but the derailleur probably has enough room for adjustment to fit the wider cassette (edit: actually, it was 7-8 so it definitely should work).

The derailleurs for more speeds require a corresponding shifter to work correctly. Derailleurs from other brands are also not compatible without tricks with adapters, with the exception of some old SRAM units specifically marketed as Shimano compatible.


What does the term pannier really mean? Does how the bag is hung matter? This question drew my attention to pannier here. I just thought that panniers are things that hung on bike. The Wikipedia definition with Google gives:

  A pannier is a basket, bag, box, or
  similar container, carried in pairs
  either slung over the back of a beast
  of burden, or attached to a bicycle or
  motorcycle.

So can I call every bag that hangs even a little on a bicycle a pannier like a handle-bar bag? Or is it essential that it is in pairs? I have panniers-looking side bags but they are not really in pairs rather separated similar bags, I bought them separately. So what are really panniers? Do they need to be attached to one-another or can they be separated? What about if I lost one, is it still a pannier or is it a piece of pannier? When I have a small bag like triangular bag or something else hung from the bike, is it a pannier? Probably not, is the proper idea to think about panniers like a bags on a donkey i.e. rather large bags?

In English, panniers originally referred to bags slung across the back of an animal (such as a horse), such that the weight hung down on either side of the animal. This keeps the weight lower so that the animal won't be as off-balance, and distributes the weight evenly.

On a bicycle, the term is used for containers that resemble that, even if it's only on one side.  Specifically, bags that hang on the side of a rack. It's also used for containers that aren't bags, such as buckets, baskets, or hard cases; though most often for bags. The term is used equally for bags on the side of a rear rack or front rack.

A pannier could attach itself to the side of a rack (typically via hooks), or you could have a single unit where two side-bags are attached to each other and held on by the attachment between them sitting on top of the rack. The attachment could be as little as a strip of cloth, or as much as a whole third bag that fits on top of the rack. Even if it's one unit, something that hangs on both sides would be pluralized as "panniers" while a single bag on one side is singular ("pannier").

If a bag is designed to fit on top of a rack without hanging down the sides, it's not a pannier. Typically those would be called a "rack bag".

A bag that hangs from the saddle (seat) is a "saddlebag". However, on a motorcycle, saddlebag and pannier both refer to containers hanging on the sides (the saddle on a motorcycle generally extends to the back). On motorcycles, "saddlebags" are commonly hard cases that wouldn't otherwise be called "bags". The huge difference between a motorcycle's "saddlebags" and a bicycle's "saddlebag" sometimes causes people to incorrectly refer to bicycle panniers as "saddlebags" even though they aren't attached to or even near the saddle (seat).


Chain clicks when the back wheel is in highest and lowest gears When I have my back wheel gears in either the lowest gear or highest gear, my chain clicks as I pedal.

How do I fix this?

You may need to adjust your derailer limit stops (see here).


Is It ok to store your bike outside for 8 hours/day? The place where I work has some bike racks outside with some basic roof on and not much else. That means if it rains it won't fall directly on the bike, but otherwise it is exposed to the elements. Is it ok to store my expensive mountain bike there every day, all year round, for 8 hours/day? Or will it get damaged over time?

If weather is the concern, yes.  You will get some damage over time.  Most of that will just be accelerated wear of all the normally wearable components.  Keep your chain lubed or it will rust.  You will go through grips, tires and seats faster.  Any bolts that aren't alloy or stainless will rust.  Non-stainless cables will rust through.

That is not the only concern though.  You will be exposing your bike to a greater opportunity for theft or vandalism, especially when it becomes obvious that bike sits there all day.


Cycling's effect On The Bladder? What effect does cycling have on the bladder?

There is some information online:

Beginner Triathlete

  It is not uncommon to have genitourinary symptoms caused by prolonged contact with the bike seat.  These symptoms can include numbness and tingling, erectile dysfunction, hematuria (blood in the urine), overactive bladder, and even a transitory decrease in sperm production.

Livestrong

  Bicycle riding combines two key triggers of female urinary tract infections -- friction and bacteria. If you're a woman and an avid cyclist, understanding the mechanics of infection and taking the right precautions can minimize the chance you'll contract a UTI during during this physical activity. If you're a male cyclist, little if any evidence shows a direct link between bike riding and infections, but the mechanics of cycling can aggravate another condition with symptoms mimicking bladder infections.

Pacific Urology

  While the physical and mental health benefits of cycling are clear, there can be negative urological consequences.

(although that seems to be more about sperm count than anything else.)

Opinions seem to be contradicting, though. Is there anything conclusive?

You likely won't find anything conclusive, because the required testing would be so varied.

Anything done poorly can cause problems.  Any sport lends itself to an increased chance for injury.  However, proper technique and equipment generally alleviates some, if not most of that risk.

In cycling, proper hygiene, attire, technique and bike fit are all important.  Keeping your skin clean (before and after rides).  During rides (especially longer rides) chamois cream of some sort can help immensely.  Bike shorts are made for a reason: they work.  They should also be clean, however.  Other attire is also important.  Overdressing and sweating yourself out only creates a breeding ground for bacteria.  Remember body odor varies from person to person, but is largely caused by the flora on the skin.  No reason to build it a Disneyland unnecessarily.

A properly fitting seat and bike will minimize friction and irritation.  These factors can cause surface skin damage which then leads to infection (saddle sores, etc) after the skin begins to break down.

If you are referring to bladder infections, I think it would be a long road with a lot of ignorance to get there.  While females are generally more prone to UTIs, and cycling could increase the risk of those, the steps necessary to reduce the risk are quite easy and really part of basic hygiene.  Getting a UTI and then ignoring it long enough for it to hit the bladder would require an additional step of disregard.


Replace a 2.0" tyre with a 2.1" studded one? I'm looking at replacing the tires on my GT Aggressor commuter bike with studded tires for the winter.

Based on the current tire sidewalls (the rims themselves don't actually have the width or diameter of the wheels on them), I'm looking at getting a 26x2.0" studded tire set.

Thing is, a local winter bike gear supplier carries one pair of 26x2.0" studded tires, and upwards of a dozen of (generally higher-quality, better-reviewed, knobbier) 26x2.1" tires. Would putting a 2.1"-wide tire on a (supposedly) 2.0"-wide rim be dangerous for the bike or the rider?

Look at what clearance between the tire and the frame do you have now. Often the tightest place is the bottom stays.

Changing 2.0" to 2.1" increases the tire diameter by about 2.5mm ("about", because the rim width stays the same and does not proportionally increase), i.e. the tire grows ~2.5mm upwards and ~1.3mm on each side. Not all tires are measured equally, some "2.1" tires may be wider than others, so add one millimeter more to be on the safe side. Besides that, knobs make the tire higher, attempt to account for that too.

If you conclude that there is enough space to fit the wider and knobbier tire, there are no other obstacles to replacement.

(Not directly related to the question, but I'd strongly recommend buying higher-quality studded tires. This is an item which brings much more value for the money than any other bike part.)


Are revolights a good idea? I've recently seen this:
http://www.kickstarter.com/projects/revolights/revolights-join-the-revolution?ref=spotlight

Basically it's leds on the wheel + a timing mechanism + persistence of vision effect. The video on the web page shows it in action.

It seems to me that this immensely enhances riders visibility (it's really hard not to see what basically looks like a Tron Light Cycle), but I can't really judge how good is the lighting provided in terms of seeing in the dark, or if the design brings serious reliability concerns.

In conclusion, would these lights make safer than a “normal” light, or is just a costly gimmick?

I don't believe these are "better" or "worse" than other lights, rather they are a supplement to other lighting systems. I think the inventors' claims about forward and rear illumination are somewhat questionable as it won't compare to a real head/taillight of similar cost.

However, I think they would provide some improvements in side and off-angle visibility. They are "eye catching" because they are distinct which is a very important factor to being noticed by other road users. There are actual lights which also provides superior visibility to any reflector-based solution available on the market today. Based on what they claim (and what is visible in the videos), these will provide nearly 360 degree visibility.

Mathew's answer makes some excellent points about weight and relative brightness. However, I disagree with his point about using a reflective materials as a potentially better solution. I have used many types of reflective materials ranging from reflectors to polished metals to 3M SOLAS-grade reflective tape. When you are within the "optimal" range of angles, they provide an incredibly bright surface for a long distance. However, when viewed from an off-angle or when the light is not directly shining on the reflective surface, their illumination characteristics are relatively poor--even when using a the high beams on a car.

There are many situations where a car's headlights are not illuminating the area the driver is looking (i.e. the driver is looking left or right) and the amount of light striking the reflective surface is minimal. Products like the revolights and the down-low glow tube are attempting to solve that type of problem--i.e. anywhere that reflective materials may not be reliable and your "normal" headlights won't provide adequate visibility.


What is the brand/model of my bike frame? Does anyone know what brand/model is bike from photos or serial number?

I see a 1970s steel framed road bike of decent quality.

It has cottered cranks which went away before the 80s, and it has quality centerpull brakes.

I can't guess the maker, but it smells like a European bike to me.  The Woods valves may imply Dutch or English or Japanese, but its just as likely to have had other tubes fitted over time.

There are some brake bits and gear shifters missing and parts that need replacement like tyres and tubes, brake pads and probably chain.  However its 97% there and could be easy to get going again.  Main gotcha is the condition of wear parts like headset and wheel bearings and BB races.

The side photos show a fork with comparatively little rake on it compared to the era.  So this bike would have felt lively and easy to turn.  That reactivity would be valued in a race situation, but less so on a commute or long-distance bike.

Note the quill stem seems to be raised up a lot - Do check the minimum insert line is down and not visible.

Totally loverly bike.  You could do a bare-minimum fixup and ride it, or you could do a full-on restoration with re-chroming and everything.  Whether you stay with 27" wheels or go for the slightly more modern 700c wheels will depend on whether the brakes will reach a 700c rim - you need 4-6mm more reach on the brakes.  Or possibly change brakes for long-reach dual pivots like Tektro 559.


My child seems to have difficulties riding bike - would different tires help? My son is 6 years old, weighs about 20kg himself. The bike we have for him is this Merida Matts J20 which weighs about 13kg.
His riding skills are fine but I get the feeling he's not comfortable on the bike. He often raises himself from the seat and rarely rides in a straight line, which frequently leads to minor accidents.
We're not going fast - about 10km/h average - but it seems he still needs a lot of effort to keep going. The bicycle just doesn't seem to have nearly as much inertia as everyone else. This results in him standing up to deliver more power to the pedals and the aforementioned swerving when going too slow.
And sure, the mass and its distribution is definitely a factor here; as well as him being easily distracted and not paying full attention to the road, but... feels like it should still be better than it is.
I've tried spinning the wheels but they seem to be moving freely (although the rear wheel does slow down a bit faster than I would expect, but perhaps that's normal). The tire pressure also seems normal, but I'll check tomorrow with a meter.
I'm wondering if perhaps tires could be a significant factor? They have a large protector like for off-road usage and we're riding almost exclusively on paved sidewalks:

Would the bike handle better with smoother tires? Are there any other tips you might share that could help? Or is this just par for the course with 6 year olds?

Update
I increased the tire pressure to 3.5 bar (was below 2) and raised the seat by a few cm. This seems to have made a significant difference and he is riding better now. I also checked with a LBS that the rear wheel was turning normally. He still likes to raise himself from the seat but is now riding with less swerving and seems to require less effort. Here's a picture, maybe there's something else that can be gleaned:

Not a helpful answer, but I would definitely find a lighter bike. In the UK, Frog and Isla are popular makes for light bikes. I would say a 20" wheel is OK for a 5-6 year old.
A single-speed Frog 52 (20" wheels, 10" frame) weighs under 8kg.  Make sure the saddle is high enough, and raise it if he looks uncomfortable.
Both my children had Frog bikes and did fine. We bought ours second hand. They are very expensive, but maintain their value, and we sold both of ours for a profit when both children had outgrown them.
I doubt tyres will make any difference.


When do I know the drum brake is at the end of life and needs replacement? I have a city bicycle with a drum brake. Since the braking parts of the system are inside the drum I can't see if it is worn out or not. Are there any indicators that give that information or at least an hint? (e.g.: squeaking sound, some marker on the drum, whatever...)

As the drum brake surface wears down, you will have to keep tightening the adjustment bolt so that the drum lever arm moves forward (towards the front of the bike) more and more.  Sheldon has some images and explanation that you might want look at:

Drum Brake Adjustment
When brakes are new they may have to be adjusted frequently (until the shoes have become properly bedded in).
With cable-operated brakes the small locknut (A in the diagram) is first Loosened off and then the knurled adjuster (B in diagram) is tightened until the brake shoes are felt to be rubbing on the inner surface of the hub shell. The adjuster is then Loosened just enough to allow the wheel to revolve without friction, and the locknut is tightened up again.

If your bike does not have an adjustment nut/bolt at the drum, you will have to undo the retaining nut, cinch up some more brake cable, and tighten it back up.
You know you've used up all of your brake surface when:

The brakes are making a horrible grinding or scraping sound and/or aren't working efficiently (note: they might be just glazed so you should take them apart and see if the brake surface is glazed; if so, deglaze it with sandpaper)
The brake drum lever arm is almost all the way forward and is limiting your braking performance
There's a little arrow or other indicator on some brake drums by the brake lever arm which indicates that the brake lever arm is fully extended and worn
You've taken the outer housing off and you can visually see that the brake surface is worn down. The brake specifications should give you the minimum brake bed material that you need, otherwise I'd use about ~2 mm as a general rule.

Because of their larger surface area and because they are in the rear, drum brakes tend to have a longer life compared to front brakes.
Example
From Wikimedia commons is this image of a panasonic drum brake (front and rear). This brake has an adjustment nut/ferrule where the brake cable housing meets the brake. Note that the brake lever arm is pointing slightly backwards (towards the rear of the bike).  You should check for wear if you're at the point that you've back the adjustment out so much that the brake arm lever is pointing forward even when the brakes aren't applied.


Saddle height vs absorbing drop impacts Let's assume the following saddle heights:

ultra low (bmx, DJ)
low (slopestyle)
medium
high
ultra high (XC)

In videos on the internet we sometimes see pro DH riders riding with a medium to high saddle height. I understand that this needs experience and works for them because on some ocasions they may control the bike by pressing on the saddle or something like that.

But how can they absorb impacts from 5 (or more) feet drops? Either drops to flat or drops with a bit of a transition.

My problem is that even when my saddle is at low to medium position I'll sometimes crash my b@ll@cks when trying to absorb landings. So I either:

decide not to absorb anything and let the bike (suspensions) handle it, or
absorb a bit by leaning my back (humping) which is obviously super wrong and dangerous and has already caused me some lower back pains

Any ideas on how they do it and whether [1] is the key on those situations?

The pros you see on the videos set their saddle depending on the DH course. If the course has a lot of possibilities for pedalling and not many drops - set it high, so on flat sections they can rest their bum on the seat and give it a full pedalling power.

If the course is rough and steep - no racer will have the seat high. So you should do. You know what you are riding, you know that you are going to do drops - set the seat low.

And leaning back is not always wrong. As long as you don't overdo it and don't send yourself flipping backwards. It all takes practice and time.

If on the drop you let your suspension handle it all and keep your legs straight - at some point suspension will bottom out and shock through your straight legs will go into your spine. And that is a direct ticket to spinal injury.

So the best is to learn to to do a bit of both - work your legs and let the suspension do  work as well. If you feel that the landing is going to be rough - move yourself to the side a bit, protect your groin, take the hit with your thigh. You might crash in that case, but your kids will be happier -)

And one more thing, in DH drops to flat higher than 5 feet are very rare and are considered dangerous. It's not trails for you, where guys carefully absorb 10ft flat-drop with their whole body. On the other hand, drops to transition do require different technique (comparing to drop to flat) and give less stress on a bike and a rider.


Derailleur Pulley Wheel Compatibility I can't find replacement pulley wheels for my derailer that are explicitly made for it.  Should I be safe replacing them with a set with the same number of teeth (i.e., the same diameter) and targeted at the same "speed" chain? I figure the "speed" of the chain would be a good proxy for the axle width of the pulley; is this actually the case?

If not, is this difference just dependent on the company that produces the pulley wheel? Should I be safe replacing a Shimano pulley wheel on a ~3 year old Shimano derailer with a current Shimano pulley wheel?

You'll probably be fine if you buy the wheel from the new version of what you have now. Probably. Shimano especially have a reputation for tweaking things just enough that last years parts don't fit.

The real issue is the axle diameter at the centre of the jockey wheel. If that matches the rest is likely to be fine. Unfortunately there's no real way to work this out from online photos or specs, since it's not one of the things that's listed (it only matters to people in your position, no-one else)

If you can find someone with the new derailleur who will let you take it apart to compare jockey wheels that would be ideal. A bike shop is likely to have one in stock that they can do this with, but the labour cost will probably be more than the price difference between the parts and the whole derailleur.

This is another case where if you have the second hand parts handy, try them and see what happens. If you can, it's probably better to scrounge a cheap/free second hand derailleur rather than buying new parts. IME a lot more people break rear derailleurs than wear then out, so it should be relatively easy to find someone who has a broken one with working jockey wheels. I'd try your local bike recycling group if you have one, or a tip shop. Basically, anywhere with a big pile of donated bikes that you can pick through.

If that fails or isn't an option, I'd look very carefully at the cost of replacement jockey wheels that might work compared to the cost of a new derailleur that definitely will work.


Rear pannier bags on touring mountain bike Why people are not using rear pannier bags on MTB for touring? Most of reports and photos I see have a saddle bag and the rest of luggage seems to go to the front of the bike.

I have done touring only on road and CX bikes before and loved rear panniers. Would it be a bad idea on MTB?

One issue is heel clearance. You can normally sort this out but not with large panniers especially with big feet.

A bigger issue is fitting a rack. Your options are very limited if you have rear suspension (including low weight limits); even disc brakes are a restriction, though not as much in the last few years.

Panniers also add quite a bit of width where you don't want it on narrow trails. Typical bikepacking bags are narrower and often higher.

On steep uphills you don't want too much weight at the back - the front wheel will lose grip or even contact. This is worse on MTBs than even the same trails on a bike with a longer wheelbase, no suspension, and harder tyres. Steep descents are less of a problem in that you wouldn't normally do them fully loaded.

I suspect that the MTB touring you've seen isn't as heavily loaded as the road/trail touring you've ridden.

These factors combine to influence another: habit. People copy what they've seen, often applying this copying to milder conditions (e.g. using solutions that are necessary on a full-sus, but on a hardtail).


Seat stay width issues Hi I currently ride a decent spec 2003 mongoose full suspension but I find that the seat stay is slightly too narrow to run my maxxis high roller 2 2.3 tyre without it rubbing on the frame. In theory if I was able to find an appropriate length seat stay of I wider fitting even if it's not for my frame would I be able to swap out the seat stay and thus run my wide tyres? I don't see an issue as long as the seat stays are the same length and have the same shock fitting and attachment to chain stay.

this is what I was thinking of swapping out


Orientation of asymmetrical brake pads on front vs. rear I'm replacing some old cartridge pads that I can't find inserts for with one-piece Kool-stops. Both are asymmetrical types, but the front set of old shoes are explicitly designated for "tail-forward" installation (see image). The only reason I can think of for doing this is for clearance of the fork when cable tension is released. Assuming that this isn't an issue in this particular case (it doesn't look like it would be) is there any other reason to follow this example, rather than installing in the more typical tail-behind orientation that the new pads are designed for? Context is cantilevers on suspension fork brake arch, if that makes a difference.

Some of the KoolStop pads have a ramp at the leading edge (facing in the direction that the wheel rotation comes from – i.e., towards the back of the bike) that is supposed to help sweep water and other contaminants off of the rim. If you have these you'd want to face them in the right direction if you can.

Other than that and clearance I can't think of a reason why it would matter unless the pads are the type with replaceable cartridges in which case you need to make sure that the open end of carrier faces towards the rear so that the pads are pushed forward against the stop.


Is China dumping cheap spokes on America market? My Raleigh dealer told me my spokes keep breaking because China is dumping spokes made with cheap metal on American markets that rust from the inside.  I'm being charged $100 US dollars to swap Chinese spokes for American spokes on the front wheel only.  He says this is a problem across the country, but especially here in NE Florida.  What should I do?

The short answer is, "Find a dealer you trust."

Whether what he told you is right or wrong, you clearly believe he is having you on.

That will not result in a good relationship, no matter whether he is scamming you, or not.

Most likely, he is either poorly educated on the cause of the spokes breaking, and is having difficulty explaining something to you in an effective manner, and is therefore making stuff up, or he is having you on.

Either way, move on.


Slimmest tyres for semifat rims I am interested in getting a bike with 27.5+ wheels (that could features tyres up to 3.25".
I'd like to know what is the thinnest tyre I could mount on such a wheel in case I want to have more speed and less "power".

I wouldn't go much narrower than 2.4 on the 27.5+ wheelset which is usually 40 to 50mm wide, maybe 2.2 if it's got 35mm wide rims as some setups prefer. Keep in mind that you drop your bottom bracket quite a bit when you size down, so you might get more pedal strikes and different handling by using smaller tires. I wouldn't go smaller than 2.4" tires on a bike designed for 27.5+ tires.

However, you could likely use a standard 29x2.2 tire on a 29er wheelset on the same bike which should be about the same diameter as your 27.5+ wheel & tire. It's a bit more expensive to have a separate wheelset, but it can give you the versatility to swap between fat and skinny widths.


Loose crank exercise bike I have an older Multisports EnduroCycle 550. The crank seems to be loose - the pedals wobble a bit side to side. How can I tighten that back up or do I need new parts?

You need to figure out what's wobbling.  The pictures I find suggest that it has a three-piece crank, so you can get wobble from three sources:

The pedals are wobbling where they screw into the crank arms.
The crank arms are loose on the crank shaft.
The crank shaft is loose in its bearings (or the bearing cartridge is loose between the "cups'.

The "fix" is to tighten whatever is loose.  So very carefully examine:

Hold one crank arm and try to wobble the pedal screwed into that arm.  Repeat on the other side.  You should not detect any looseness (save for a small amount in the pedal bearings).  If you do detect looseness, use a wrench to tighten the pedal shaft into the crank arm -- clockwise on the right side, counter-clockwise on the left side.
Hold one crank arm and try to wobble the other arm.  Try to detect looseness in the connections between the arms and the shaft running between them.  If you detect such looseness you need to tighten the bolts that hold the arms to the shaft.  This is generally a right-hand thread on both sides.
If you detect no looseness when you wobble one crank arm while holding the other steady, but the whole assembly of crank arms and shaft seem to rattle as a unit, then the cups holding the crank bearing need to be tightened.  I'm thinking the right cup uses a left-hand thread and vice-versa, but I don't recall for sure.  And if there are loose bearings for the crank shaft, vs a "cartridge" of shaft and bearings together, then you need to use some care to get everything just "tight enough", without over-tightening.

Of these possibilities, #2 is the worst, as riding with your crank arms loose very quickly damages the arms to where they will no longer fit tightly.


how is the middle of a folded Brompton supported? I have a Brompton customised by Kinetics and notice that when placed on its side the upper parts seems to be supported by:

at one end, by the frame hinge, and
in the middle (near the fork catch) by the front hydraulic disc brake caliper body pressing against the chainring guard.

There appears to be no other support, so if something is subsequently stacked on top of the bike, I'd guess it would stress the caliper and crank/chainring. Shopping-trolley mode with a loaded bag may also cause pressure between these parts.

How does a normal Brompton, lain on its side, support itself in the middle?
How much weight can sensibly be put on top?

The reason I ask is that I bought a chubby trailer which can hold the brompton but it provides no protection against something heavy being placed on top of the bag in transit. Given this problem with the custom Brompton I am curious as to how a normal Brompton behaves.
In case it make things clearer, I'm thinking of the brompton on its side being like a <, where the point is the frame hinge, the top is the handlebar side and the bottom is the rear triangle side. I'm trying to find out what contact point (or points) along the inside prevent a normal brompton flattening into -.
I don't have access to a normal brompton and have been unable to find detailed images of the inside of the fold. I'm fairly certain the middle isn't supported by the fork hook (that stops the fork moving outward, not inward). I'd guess the left fork blade eventually comes into contact with the right chainstay and that contact point provides the support but it would be nice to know for sure.

Here are a couple of pictures of my (not-very-clean) bike.
Despite appearances, the only places that the left side (front-of-hinge: fork,handlebars,etc) and right side (back-of-hinge: frame, rear triangle, etc) will be in contact when the bike is laid on its side are at frame-hinge and brake/crank (circled in red):

Close-up of the brake/crank contact point:

From a phyics or engineering point of view, I don't know, something on the order of 20/30 kgs, maybe?
From the warranty and manufacturer recommendation, the answer is 0.
A folded Brompton (and other foldable bicycles) are not supposed nor meant to carry any weight.
You can still revert the order on your trailer, put the heavy stuff on the bottom (which is  in any case a meaningful thing to do) and then the Brompton on top, fixed with some bungee rope or with some other kind of band/belt.


Removing Seat Post rusted into downtube I have an old steel frame (Columbus Number 2 I think) that has the seat post (Suntour Superbe Pro - see, I said it was old!) rusted in. I have tried lots of WD-40 but it will not budge.
Any tips on how I can get it out without having to cut the frame up?

Before you take any more forceful measures, it may be a good idea to think a little about chemistry:

'Rust' is typically the name put on any type of corrosion, but technically & specifically, it is the corrosion of iron (or steel) to form iron-oxides.
Although your bicycle is most definitely steel, your seatpost is not -- it's aluminum-alloy, which does not 'rust', but definitely corrodes (creating aluminum oxide).
WD-40 is a penetrating oil which is designed to, amongst other things, break up iron-oxides. However, it is pretty much useless against aluminum-oxides, especially when they have already corroded & bonded.
Ammonia, however, is spectacularly good at eliminating aluminum-oxides.

Therefore, if WD-40 isn't doing the trick, get some ammonia, apply it in a similar fashion, and let it sit. It may just be all you need!


How long can I safely use a chain for? My chain is well over the 0.75% extension at which I would normally replace it.
 However, the cassette and chainrings are also old enough that a new chain would slip on them, so they would also need to be replaced.

The drivetrain currently works, despite being worn, so there doesn't seem much point in replacing anything yet.

How long should I leave it before replacing the entire drivetrain?

The problem with worn, stretched chains are: increased wear on the cassette sprockets and chainrings, poor shifting, chain slipping on the sprockets, reduced efficiency and increased chance of the chain snapping.

Normally it's considered 'safe' to run a chain up to 0.75% elongation before risking encountering those problems. If you really care about sprocket and chainring wear replace at 0.5% elongation.

If the sprockets and rings are already well worn and everything seems to be working OK for you, just keep going until problems really start to manifest or something fails terminally, at which point you replace the cassette, rings and chain in one go.

Chain slip or the chain snapping could of course put you in actual danger of a crash, especially as both are likely to happen when you are applying maximum force on the chain in a low gear ratio.


What should I look for in a new front wheel for my heavy body? I broke my second front wheel last night when I hit a dip that rose too quickly on the far side. The wheel didn't get a chance to redirect the force upward before all my weight went behind it.

I'm a big guy, 300+ lbs, so I need some sturdy wheels. Especially in the front. From what I am reading so far I should go for a wheel with a wider inner width. The Mavic CrossOne 29er wheel that I broke is 19mm.

I ride a 2014 Specialize Rockhopper Comp 29er. It has been an awesome bike for the most part. The only problem I have been having is the wheels really. I don't want to keep replacing them. I really like the tires that came with it. The Ground Control 2.1" tires.

Please help me figure out what I need to do to find a wheel that can survive my heavy butt. What do I need to look for in a bike?

The things that will make a wheel more durable in this kind of service are:

Bigger tires – the bigger the tire the more space you have to cushion an impact, bigger tires also mean that the load is more distributed. Since the bigger tire gives you more support you can also run a somewhat lower pressure which means that there is more flex in the tire before the rim takes the impact.
The right tire pressure (especially since you may not want to change your tires). Too much pressure will make the tires hard and will transfer more of the impact to your wheels and the rest of the bike. Too little pressure means that you'll be getting pinch flats and impacts on the rims – also not good.
Proper spoke tension – the spokes support the wheel, making sure that they are tight enough and evenly tensioned will ensure that the wheel is getting as much support as possible.
Deeper rims – a deeper rim section will be stronger under impact. Wider will help with lateral loads. Going too wide will straighten the sidewalls of your tires and may actually reduce their effectiveness at cushioning impacts.
More spokes – hubs and rims for tandems can be made with 40 or even 48 spokes, if you're already running 36 spokes and they were properly tensioned I'd be inclined to go for more spokes when you build the next wheel.

I think the width of the rim is more about matching the rim to the tire (and lateral strength) than about radial impact strength. That said, 19 mm seems kind of narrow for a 50+ mm tire (at least based on this table of rim widths from Schwalbe). If you've got clearance on the bike for a wider tire, I'd go for at least a 23 or 25 mm rim just to have options.

Another source of good advice would be a wheel builder who specializes in durable wheels. In the US Peter White is a possibility.


Damaged rim, can it be fixed? Cycled my friend’s bike and fell forward. Hoping this can be fixed.

If the damaged wheel comes with a cheap to midrange bicycle, it should not be fixed for economical purposes. What you should do is to buy a new matching wheel. Otherwise the cost of replacement rim, new spokes and nipples plus manual labor of a wheel builder may easily overshadow the cost of a complete factory-built wheel.

If you are really determined to save the most of the wheel, you should look for a matching replacement rim. Fixing the current rim is unrealistic as there is no ready equipment for that, and DYI would most likely make an unbalanced wheel or unreliable fix.

Sad things like this happen. I was backpacking once and discovered that my rear rim cracked exactly at the midway point of my trip. Managed to get back home safely and made this picture:

It was extra sad because I changed a faulty hub on the same wheel barely several months before that, and the first hub only did 40 km.


Do rollers ruin tires? I started using aluminum rollers to ride indoors this winter and noticed streaks left on the tires.  I've also seen tires specifically advertised for use with rollers.

I'm wondering whether using the rollers will tear up or degrade a high quality road tire in any way?

It's generally a good idea to use a trainer tire for a trainer, because the tire wears down significantly faster (plus they get hotter, make more noise, etc).

Rollers don't cause as much tire wear as a trainer does, but they aren't exactly the road. Many people use their regular road tires on them without any adverse effects. Some people experience increased wear (on the back, usually).

If you're really worried though, just buy some cheap 15 dollar tires and put them on your wheels. On a trainer, they wont last as long as a trainer tire but they will save your good tires. On rollers, you generally have less wear, but still, you're going to save your original tires (since they aren't being used).