biking with lower back pain I have regular lower back pain (mostly mild, with severe episodes during which I generally stay home; there's nothing wrong with my spine, I just sit at a computer too much).  I just started biking to work - it's just a couple of miles and pretty flat, but having my back arched still doesn't feel very good.

What biking position should I try for?  Any particular adjustments to my bike I should consider?

Others have mentioned good tips about position, but I thought I'd add a few things other than that which I find helpful to reduce lower back pain:

I stopped carrying any sort of bag on my back (no matter how seemingly light!) and switched a rack with panniers
I stretch after riding, focusing particularly on my lower back (obviously), but also my buttocks and hamstrings, since having these tight can lead to lower back pain.
When I'm getting back into commuting after not riding for a while, I give myself more recovery time between rides to gain strength. In other words, don't start from zero biking days to biking every day and expect to not be in pain.

I've found that these steps have largely eliminated the problem for me.


Troubleshooting Hydraulic Disc Brakes I replaced the fluid in my hydraulic disc brakes as they would not work within the first 10 minutes of cycling and would gradually sharpen up. I suspect they had air in the system.

They were sharp for about 2 weeks after replacing the fluid, but now my front brake has almost no stopping force.

How do I determine the cause of the issue?

Should I replace the fluid again?
Could there be a leak in the system?
Do I need to replace the tubing/screws?

Thanks

Tracking down issues with brakes can be difficult.  If the brakes are spongy feeling initialy and pumping them firms them up then you probably have air in the system. if that's the case then it will be a bad bleed or the seals or possibly the brake hose but working out which is often down to luck. If they just have no power it could be contaminated pads.

If it was me then I'd do the following, give the system are realy good clean and finish off with disc brake cleaner if you have some.  Next I'd re-bleed the brakes (having first pushed the pistons right back) and then fit new pads.  Use the brake somewhere safe and then inspect everything to see if you can spot any leaks at the levers, hoses or calipers, take the pads back out and check for contamination with brake fluid.

If you do have a leak then you'll need to replace the seals and/or hoses that have failed - this can be tricky if it the caliper seals that have gone. Getting hold of spares can also be an issue.

It may be easier and cheaper in the long run to replace the brakes. Shimano Deore are relatively cheap and very efective.


What's a good bike for daily use in New Orleans? A flat city with lots of potholes and bad roads Something under $500 that is relatively unbranded.

Better yet, look at a 29'er. Like this one.from Kona, Single speed, rigid, fat tire MTB. Run fat tire slicks, and it's a great commuter. The lack of shifting works well on flat ground, with the right gear choice (very personal decision), and the fat large tires roll well and comfortably. MTB durability means rough roads might as well not exist.

There are many bikes like this, and while i like the Unit 29'er linkd, I'm recommending the idea, not the particular bike.

As far as branding, that can be fixed with judicious use of tape, spray paint, and stickers.


Do 29 inch wheels make a difference? Possible Duplicate:
  29" wheels - what advantage do they provide over smaller wheels?

Do 29 inch wheels make a difference off road? They certainly cost more.

Since I switched to my 29-er in september, I can keep up with the fastest bikers in my "team". Before that I just could not. It could be due to the new material, but I think there's a speed difference of about 2 km/h.

I bike on the flat tracks of nothern Belgium and the south of the Netherlands. So no climbing or descending.

The 29-er is definitly faster on (loose) sand, and mud. And a lot more comfortable on tree-roots and the "Belgian Blocks".

For really, really small turns, I notice the wheelbase is larger, but otherwise I do not notice any difference in handling.


Bike spare parts in South America I'll soon start a rather long trip from Ushuaia in southern Argentina to Alaska in the north of North America. As I'm from Europe (France), I don't really know what to expect about spare parts for my bike in South America.

I'll ride a Kona Rove ST, a gravel bike with 650b wheels and 47mm wide tubeless tires. The train is 1x11 SRAM. How easy do you think it will be to get new tires, gear parts, tubeless sealant and other spokes?

I have around 1 year touring experience in South America. Mostly remote dirt roads and trails.

I would never ever purposely run tubes again.

As long as you are confident in your tubeless setup flats should be almost nonexistent. I only carry one tube for emergency that has never been used. A small bottle of spare sealant is pretty essential to top off if you start to get small air leaks. Needle and thread to sew small cuts, as well as tire plugs. A few patches if you are forced to use a tube.

All decently large size cities in Chile and Argentina should be fairly well supplied with bike parts (somewhat less so in other countries in my experience). If not, then it is usually easy to travel by bus somewhere bigger. If you are in big cities (especially capital cities) can be good to stock up or change parts, especially if you are headed to remote areas.

Tubeless sealant is becoming more and more ubiquitous, especially in MTB communities. Usually these guys are not running tubeless specific tires, and they make it work. 650b mountain bike tires will be easier to find than road or gravel tires (could be an issue, not sure what tire clearance a kona rove has?).

SRAM parts can be much trickier to find than Shimano. Old shimano standards are king. Dub and GXP bottom brackets/chainrings could be difficult (especially 1x). I believe Peru only recently has an official SRAM importer.

I would carry plenty of extra brake pads, they are light and depending on your brake model could be difficult to find.

Generally just keep an eye on parts. Be religious about cleaning and oiling your chain. Have a good idea for what is wearing and when you might need to replace it, and plan ahead.


Brakes feel like they are not even there on my used road bike. How can I fix it? My friend gave me his old sanwa road bike that had been sitting in the snow for about a month. It looks like the one from the 1979 movie "breaking away" but with a different color and brand (to give you an idea of how old it is). Anyways, the brake pads look brand new, they look like they engage properly when I use them, they stop the tires instantly when I use them while I have my bike flipped upside down, but then when I hopped on my bike and pedaled to about 10 mph and pulled the brake levers, I could hear the brakes quietly squeaking a bit against the metal rim of the wheels, but it took 50 feet and a crash into a 10 foot tall pile of snow in an empty parking lot across from my apartment to stop... They felt like they had been cut as soon as I hop on the bike but work fine when I'm off it. From what I can tell, they are supposed to be positioned so they hit the metal wheel rim (they are), in a "V" shape pointing forward (they are), and from what I can tell they just barely don't touch the rim while I'm not pulling the levers. Any ideas on how I can fix this? Any and all help would be appreciated! Thank you.

It is quite possible the brake rubber is old. Or the rims may have an oily residue on them. As the pads age they become hard and dry. The result is long stopping distances and brake fade. You can try to use a file on the pad brake surface to remove the driest rubber. Avoid sandpaper as the grit can get lodged in the rubber and damage the rim. The results don't typically last for long. Replacement pads are inexpensive and easy to install.


Are lighter chains worth the cost? I'm replacing chains on a number of bicycles, and trying to decide what chains to purchase.  I'm a fan of Sram's master links, so I'm comparing the Sram PC-971 to the PC-991.  The PC-991 is considerably more expensive, but it seems like the lighter weight chain would make a significant difference in pedaling performance, because of the angular momentum involved.  Are my instincts correct, or is this just a sales gimmick on Sram's part?

Also, I've seen some reviews indicating that the hollow-link chains are prone to breakage -- is this something I should be concerned about?

I'm no racer so I'm probably speaking from a very different point of view than you were interested in. I have used Sram 9-speed chains for years on my touring/commuting bicycles. I have used the 971, 981, and 991 and haven't been able to see any difference in performance or longevity, either. With my wet-weather commuting here in the Seattle area where it's pretty nearly wet every day from October through March, and then there's plenty of rain in April and May, too, I have been able to wear out chains and cassettes very quickly.

I'm not a mountain biker--or at least not an avid one--so I have never really hammered the chains in the muck but I have never had one of their chains break. I've just managed to wear them out over time.

I do greatly appreciate the master link because it makes it easy to take the chain off the bike and put it back on again. Before I switched to a bike with a Rohloff internally geared hub for my commuting, I would keep two chains in rotation on my bike and take one off, soak it in cleaner, and let it dry while I put the other clean chain on my bike.


Why does my chain keep jumping off the front chainring on my 1x9? My chain has a tendency to frequently jump off the front chainring. I have a 1x9 so it's not a front derailleur issue. It generally happens when I hit something like the lip of a driveway or sidewalk at a crosswalk, which sucks when it pops off in the middle of crossing a busy highway in town. Could my chain be a bit too loose?

Is your front chainring on the outside or inside of the spider? Is it a converted 1x9 or did you purchase it as a 1x9?

It's most likely happening when you hit large bumps or holes in the road. It's possible that your chain is too long if you converted it from a 2x9 and didn't reduce the number of links in the chain.

If you converted it, it's also possible that the chainring is just too far away from your center line for a proper chainline when you're on your largest cog. If possible, move your chainring to the inner side of the spider. If you have a single ring crank, you may need to get a shorter BB/spindle.

Another cheaper and easier solution is to get a chain watcher. There are several types and brands such as N-stop, K-edge, Paul Components. This will sit on the inside and/or over the top of your chain on the front chainring which will help prevent the chain from jumping off the front ring. They are used widely in the cyclocross world to prevent this.


New bicycle for commuting I'm just retiring my old roadie and looking to buy a new bike, and am torn on what kind to buy.

I cycle 34 miles per day on my commute, down roads and canal towpaths (which are bumpy and have on several occasions wrecked the wheels on my roadie).  I also like going out on long leisure rides.  For that reason, my initial thought was that I should get a touring bike, which would be able to handle the potholes I encounter daily.

The other problem I have though is that I have no proper outdoor space to clean the bike, and this has caused many issues with my roadie (which doesn't have mudguards), which got super gummed up.  I have taken it up on the roof through a window to clean in the past, but its a bit of a pain.  I really like the idea of an internally geared hub, but I can't find any touring bikes within my budget (£1000) with one.  I did find the boardman URB 8.9, which looks really nice, but I'm not sure if flat bars are going to be a problem on longer rides.

I really don't know what to do, please help me!

I had experience with riding of different bicycle types for commute, my distance was around 20km per day:

MTB: tires are bad fit for the job, so you put on slicks, running out of gears on asphalt flats/descends, sitting too high, too wide bars, extra weight from the fork. Makes sense only if you ride offroad for a major time of your commute, like one of my colleagues does.
Cyclocross: not bad, more aggressive geometry than road bike works fine for 10km ride but may be a pain for a longer one. Tires work both on asphalt and outside of it. But CX bikes are usually not coming with mudguard mounts, and tire clearance is usually limited to 35-37mm (due to 33mm official CX limit by UCI).
Road Bike: works great during the summer for longer commutes or when the weather is dry. Gets you to work ASAP. Many positions available on the handlebars. Slicks are getting not much grip when it's +3 and wet. Not much practicality bonuses, so the extra cargo most likely is going to be carried on you. There are some <1000GBP options available with mudguards (like 2019 Specialized Allez), but with bike's price increase mudguards are getting quite rare. Rim brake versions are quite easy to maintain in my experience. Not the best choice when you get into cycling traffic jams. Can use more robust rims with more spokes plus universal set of tires like Conti 4 season to get it almost bulletproof (remember Martyn Ashton's Road Bike Party showing you what road bike can handle). I use this option during summer when I also want to involve training ride before/after work or get to work very fast beating some Strava segments.
Gravel Bike: take pretty much all of the advantages of a road bike and deduct disadvantagess like lack of mudguard or rack mounts. With clearance up to ±47mm you can have comfortable solid tires fit in without sacrificing much speed. Unfortunately hydralic disc brakes for drop bar bikes are still a luxury, unlike flat bar bikes where it's more or less standard over ~400GBP. Can be used as a tourer too, plenty of bags are now sold designed for gravel bikes backpacking which could also be useful for commute. Expected to be lighter and faster than proper tourer. My friend rides around 40km a day on a steel Vitus 650b gravel bike and loves it.
Hybrid: my new love. Bought one to replace carbon gravel bike which I believe is too much for winter conditions and only 13km/day commute (after moving to new place my commute distance got shorter). Comparing to gravel bike you get much higher riding position, which with other factors like increased weight makes me around 20-30% slower. Also the fact of not riding a fast bike helps to take things easier, I started to ride to work in jeans with flat pedals again. Having a hybrid bike I don't need to be one of weight-weenies, so I have mudguards, solid rack and a waterproof bag which make my life so much more comfortable. Flat bar works for a short distance but when I finally leave the city I really want to sit lower to make it easier to maintain higher speed. Not talking about comfort, your hands will be in the same only position for few hours daily. Hybrid bikes are usually quite cheap so I can finally park my bike outside and use for things like buying grocery. I think most of the stuff said about Hybrids applies to Tourers too.

Reliability of components

If you're able to find within your budget a bike with hub shifting - may be worth considering it. But without sacrificing the shifting abilities, because unlike other commenter here I believe that number of gears is important if you live in a hilly area. Otherwise I wouldn't bother. Sora and Tiagra levels are currently decent enough to use them hard and expect reliability to be high and maintenance to be quite easy. Spare parts are available everywhere (including second hand in mint condition due to many people upgrading from 9/10 to 11 often shortly after buying a bike) and are quite cheap. Here in Stockholm I see plenty of people riding cheap hybrids with basic Shimano groupsets and seems that they've never washed or serviced them, but they are still running.
Mudguards are actually making significant difference to how your bike is feeling and what's it's resource.

Conclusions

For your distance of commute I would definitely look for a drop-bar gravel bike with wider tires and something around Tiagra groupset. I believe that hybrid would be too slow for your use and works best for up to ~30km per day. I have much shorter distance and went for a hybrid which works very well too.


Prostate-friendly Saddle and Sitting Angle I am a 65-year-old male and every day I ride cycle for an hour for workout.

Lately, I hear a lot about cycling causing inflammation of the prostate gland. And I have difficulty in complete emptying of the bladder when peeing.

Some of the precautions suggested are

using prostate friendly saddles and
prostate friendly sitting angle.

Could someone please suggest the right type of saddle and sitting angle so that my prostate doesn’t get inflamed?

Thank you in advance for your help.

My scrotum (pardon my french) prefers this style of saddle:

I also tried this, but didn't like it. It seems good on paper, but my butt always wants to slide forward, plus not being able to squeeze the saddle between my thighs when going over obstacles means less control over the bike.

Anyway, your best bet may be a recumbent bike. I have one, the big drawback is that it climbs hills like a brick, but comfort is perfect.


What is the best way to protect frame from dents during crashes? I have a bike and I crash relatively often. I'm concerned about protecting the frame from damage.

I started searching for a way to resolve the problem and I'd like to share options that I've found, discuss their pros and cons and maybe someone would share their experience and other options to protect a frame.

Protective film

I discovered that there is a such thing as a thick protective film that can prevent minor-to-medium damage to the frame's surface. There are special film kits for bicycles, but they are expensive. I'm going to use industrial protective film which is cheaper and probably of greater quality.

Derailleur guards

It's unlikely that I will use them because during crash they may work as a lever and inflict serious damage to the frame.

Adhesive bumpers/pads

I've found special pads for bicycle:

But I didn't find where to buy them.

I also found generic adhesive bumpers:

I think I'll try them but I don't have much hope that they will work.

Motorcycle crash pads

I have a wild idea about fitting such devices to the bicycle frame. But these things also can lead to a serious frame damage.

Your bicycle is probably as protected as its going to get when it comes out of the factory, so I'd suggest doing nothing (well, maybe crash less).

Protective Film -- Cosmetic protection (possibly structural in some cases for things like cable rub as pointed out by Nathan in the comments). If you're worried about keeping your bike shiny and scratch free I suppose. Be careful with Carbon Fiber depending on adhesive. Won't protect from dents.
Derailleur guards are a terrible idea -- the force transmitted in a crash will be applied in a way not in line with design and damage the frame, whereas if the derailleur is installed as normal, the hanger will bend (or break) and is usually easily replaceable or reparable (align with something like the Park Tool DAG). If the derailleur is damaged, it's a heck of a lot cheaper than repairing the frame damage caused by a derailleur guard. You could spec an internal gear hub or single speed instead, if you want to avoid derailleur damage depending on the frame.
Bumpers -- See point 1. I see these as likely less useful than the film.
Crash Guard -- See point 2. Plus, there aren't as many nice mounting points as on a motorcycle since you have to pedal on a bicycle for it not getting in the way, whereas you only shift+brake with foot movement on a motorcycle.


How much of a mark-up do you pay building your own? So, I have read the pros and cons question, and the why it is more expensive question, but I didn't notice anything on how much more expensive it would be.

So, if I want to buy a high-end bike a little bit at a time, just how much extra will I pay for the fun of repeatedly upgrading my grandfather's bike?

It’s hard to give a general figure for how much more expensive a self built custom bike will be, but it’s relatively easy (although time consuming) to figure out how expensive your build will be. Just make a spreadsheet of all the components you will need, and research the best prices online.

Don’t forget to factor in all the minor components like grips, cable and brake housing. Also factor in all the special tools you will need to buy (or rent from a local bike co-op).

The other thing to consider is the investment you’ll have to make in learning all about component compatibility. There are some compatibility things that are not trivial to figure out.

You will also have to learn how to install and adjust every single component on the bike. That's a fairly significant investment in time, both in research and learning and the fiddling around trying to get stuff working right.

If learning all that is part of your goal (and it’s a completely reasonable one) all well and good, just know what you are getting into.

It’s also possible to scour Craigslist, EBay and local forums for parts, but you really have to know what you are looking for to make sure you get compatible components that are not worn out.


Clicking noise coming from cog on fixed gear Ever since I put my rear wheel on after taking it off, I have had this constant clicking noise from the cog.

Here's what I know:

It wasn't always like this. I rode for a few months with no clicking noise.
Chain line appears to be straight.
Clicking sound comes from the top of the cog when pedaling forward and the bottom of the cog when pedaling backward.
Chain appears to "bounce" quite a bit when leaving the top part of the cog when pedaling forward and when leaving the bottom part when pedaling backward.

Is it the same link every time? There could be a tight/sticky link in the chain from when it was installed. I'm not sure why that would have come up after removing/replacing the wheel, but it's worth checking.

Mark or otherwise make note the problem link
Take the wheel off or push it in the dropout to put slack in the
chain
See if that link is difficult to bend
If it is difficult to bend, then set your thumbs on it, push it side-to-side, quite
    firmly but not with all your might, until it becomes less sticky


Saddle / Seat slowly creeps backwards So, over the course of several months, I notice that my saddle has been creeping backwards on the seat post.
Road bike. Fizik seat post (two screws, one manual, one hex head.)  Ti rail saddle.
I tend to break seat rails. I think it is fatigue related. And I range between 200 and 200 lbs. ;)  I've used steel rails. Carbon rails seem like a bad idea. The current saddle has ti rails. I put the saddle forward because the break in the rails happens at the back, and I want to minimize flex. This is my current theory to stop breaking rails.
Anyway, I tighten the bolt plenty. I don't know how much, but I think that increasing the clamping force is not going to help, and I will eventually strip the bolt/nut.
Seems like more friction between the rails and clamp is what is needed. I don't know the proper way to do that. Any suggestions?
Thanks,
Mark

Carbon assembly paste increases friction and can be used for metals as well.
Make sure to use a torque wrench and tighten to the torque printed on the seatpost clamp.
From the photos of the Fizik seatposts it almost looks like only the back screw is actually clamping the rails and only with 8Nm tightening torque? If nothing helps I’d get a seatpost with two side-by-side screws and ≥10Nm torque.

I put the saddle forward because the break in the rails happens at the
back, and I want to minimize flex.

Don’t compromise seating position just to avoid breakage.


How to remove cantilever brake arm? I am renovating a bike, I guess it's 10 years old. It has internal gears with pedal brake. And then it has a hand brake in the front, I think it is called "cantilever direct pull". One arm was moving quite smooth, while the other was very stuck, tough not impossible to move by hand.

In the process of removing the arm from the brake boss, something remained on the boss: some kind of brass-looking bushing with a kind of rubber gasket.

The brass part was almost impossible to remove. I tried different things. And only in the end when I took a 60cm pipe wrench was I able to wiggle it off.

I felt victorious until I realized that the power needed to clamp around the bushing was enough to deform the boss itself. So now I have a slightly oval boss, just enough to notice with the naked eye. The internal threading is now too tight, but it is possible to put in the bolts though. The real problem is putting a new brake arm on the bushing. I cant even get in one millimeter onto the boss.

Picture above shows: Bushing stuck on boss

Picture above shows: The other boss, where the bushing easily slid off together with the arm

Picture above shows: After removal of the bushing, the boss is slightly oval

My question is two-fold:

1) How should I have removed the bushing, without damaging the boss.

2) How can I fix the boss now, so that I can put a new brake arm on it?

After some thought, and experimentation, I will suggest my own answer.

How to remove

I see two ways:

Without special tools

Use the pipe wrench just enough to wiggle the bushing a few millimeters out. Then use a screwdriver and a hammer to hammer it out.

With a puller

With a rather small "puller". Possibly together with this plate that can close around the boss behind the bushing. The diameter of the rod on the puller might be greater than the inner diameter of the bussing. In that case, I hope it is possible to insert a threaded metalrod into the inner threading of the boss, and then press the puller-rod against the thinner inserted rod.

The two devices need to be in appropriate sizes, and I was able to find that online in my country.

How to fix the deformed boss

Maybe I was lucky, but it was no problem at all. I just pinched on the "ends" of the oval, with the same pipe wrench. After my first attempt I was able to slide a new brake arm on, without any resistance. If that had not worked I would have used a sanding tool, maybe a Dremel.


Do higher speed crashes result in less serious injuries. I have heard that the severity of injuries tend to decrease while riding a road bike at high speed. An instance of high speed would be like those in the Tour de France.

The reasoning behind this idea is "enough" speed allows the cyclist to "roll" upon landing thus decreasing the chance of breaking bones for example.

This seems contrary to my basic knowledge of physics and momentum, so, is it true?

In "Epidemiology of bicycle injuries and risk factors for serious injury" by Frederick P Rivara, Diane C Thompson, and Robert S Thompson, the authors gave a questionnaire to 3,390 bicycle riders who had attended a hospital emergency department in the Seattle area.

They found that cyclists involved in a crash at a speed greater than 15 miles per hour were 1.4 times as likely to have a "severe" injury (defined as an injury severity score greater than 8) as cyclists involved in a crash at a speed of 15 miles per hour or less. The 95% confidence interval was 1.0 to 1.9.

(Caveats: 1. It seems strange to me that the authors only reported odds ratios, when they apparently had the data to compute effect sizes too. 2. The fast cyclists differ systematically from the slower cyclists: the odds ratio fell to 1.2 when other factors in the study were controlled for. 3. It's Rivara, Thompson and Thompson.)


Minimum tire pressure for 20 mph (32 kph) turn I almost wiped out on the morning commute while rounding a corner!

I have 700x25mm tires and usually keep them around 90psi.  What is the most you've put in your tires (psi) to insure flawless turns?

The short answer

You say you usually keep them around 90psi.

I think it's a key point that you don't say that you checked them and they were definitely at 90 psi (6 atm).

Cornering at speed is always dangerous. You need your tires to be hard so that they do not deform, and you need proper technique. Your tires need to be at least 90 psi.

Regarding technique ...

At speed you must lean with the bike. You lean the bike to make it corner, rather than steer it. At these speeds your weight should be evenly distributed between handlebars and pedals: no weight on your seat.

You should look through the corner, so that you know what you're doing next, and to keep a calm, neutral position on the bike.

Approach new corners with care. It's not a race. On a public road a crash can cost your life.

But to answer your question - my tires are at 8 atm right now - 120 psi.

The long answer

There are four key components of cornering: your speed, your technique, and the tires and their grip on the surface (and that's omitting others, such as frame geometry). Unfortunately, misinformation on each are common. So don't take everything you read on these topics as Gospel (or Torah, or Koran, or Whatever-floats-your-boat). Evaluate each source, including this one.

Each of the four components interact with the other, so any discussion of them quickly gets complicated. This is part of the reason for the plethora of misinformation.

But first we need to be clear about how a bicycle actually works.

Balance

When you learned to ride a bike, you learned how to keep the wheels under you. As the bike and you lean to one side, you steer in that direction to get the point where your wheels contact the road under your center of gravity. It's easier to keep your balance as you ride faster, because the bike responds to your steering movements faster. You can see evidence of this when two riders go through a wet patch and onto a dry road. The faster rider leaves a very straight trail. It does wiggle, as the rider adjusts to small deviations, but not much. The slower rider leaves a wriggly trail, as the bike slowly swoops from side to side.

Speed and Technique

Speed and cornering technique go hand in hand. As you gradually increase your cornering speed, your cornering technique gradually changes.

Let's start by assuming the surface is clean, dry bitumen, and that the corner is open, such as riding in an empty supermarket carpark. You can choose how sharply to turn, you can see all the way through the corner, and you know where you'll go after the corner.

Your speed and previous experience with the grip of your tires on this surface determines your cornering technique. Accordingly you may brake hard as you approach the corner, brake gently, or not at all.

Let's start with a low speed corner, where you don't need to brake. As a kid, you learned the technique for these corners - it's called counter steering, where you turn a little away from the corner in order to move your weight slightly to the inside. When your weight is to one side of where the tires contact the road, you have to turn in that direction to keep your balance. When you get to the end of the corner, you actually turn a little harder to get the wheels under you again, so that you can ride straight.

As you increase your speed, the movement you make to initiate the turn doesn't need to be as great. You can just lean into the turn. This is where some of the misinformation appears. In order to lean, you do counter-steer slightly. It's natural, once you've learned to ride a bike. But many talk of counter-steering as though it's some special technique that should be consciously applied. When we counter-steer, we deviate from a straight path. Anyone near us is now at risk - if you are riding in a group you can cause a crash this way. The term counter-steering actually comes from motoring, where the vehicle has so much power that it corners in a controlled power-slide. On a bicycle we don't have that much power. So ignore advice to counter-steer. You're already doing it. Try to do it less.

So, as you increase your speed, you need to lean more to balance the centrifugal force as you turn. As you lean the bike (and ever so slightly steer), the geometry of your bike changes the angle at which your tires meet the road. The grip of your tires on the surface produces the centripetal force that pushes you around the corner. More on this in the Grip section below.

Once you are going fast enough to be noticeably leaning as you corner, your need for more techniques appears. You will have rapidly learned that if you have the inside pedal down then it can hit the road, called pedal strike. In the worst case, this can lift one or both wheels off the road. Of course, your wheels don't have much grip in the air, and so the common result is a fall. So many go to the other extreme, and say you should have your outside pedal down. This is how you see the pro's do it. It looks good. Stylish. But they are (mostly) highly skilled riders, with bike control skills most of us can only dream of. For mere mortals, I suggest we get off the seat for high speed corners, to distribute our weight evenly between the wheels, and to feel and possibly react to what the bike is doing.

The other basic fast cornering technique is to look through the corner. Which just to means look where you're going next, instead of the nice person on the footpath, or the road in front of your wheels. The only time to look down at the road is to avoid an obstacle. The point is that you'll go where you look.

So that's basic speed and technique. If you think they are controversial, poorly understood, or with conflicting advice, take a look at ... Grip.

Grip

Grip. Rolling resistance. Tire pressure. Contact area. Gravel. Water.

These term all get mixed together when we talk about grip. So again, lets start simple.

On a bicycle, we have one main kind of grip. It's called static friction, because as your tires roll, at the point where your tire meets the road, it's not moving relative to the road.

On a dry, clean road, the amount of static friction you get depends on one thing - the force (or weight) you apply. So contact area does not alter your grip. This is, to put it mildly, counter-intuitive.

Static friction is important because it's always greater than the alternative - dynamic or kinetic friction. This difference means that once you start sliding, you're gone. Unless you have some amazing skills.

So how do you maximize your static friction? By keeping your tires firmly in contact with the road surface. And that means tire pressure (and also even weight mentioned above). Your tires need to have enough internal pressure to resist deforming under the forces of cornering. If they deform, then they lose that firm contact. They lose grip. And then you're gone.

But why do we all use lower pressure when it's wet? And why do cars and trucks have wide tires?

When our tires slide we observe dynamic or kinetic friction. We all know that this increases as a function of area, but good online sources are hard to identify. Tires with a larger contact patch grip more when sliding because the edges of treads and rough road surface features interlock as the tire moves over them, and the rubber surface squeezes around the road roughness. But this grip is always lower than static friction. We lower our tire pressure when it's wet to increase our kinetic friction. If don't lower the pressure too much we will still retain decent static grip. Since we'll ride a bit more cautiously in the wet, the trade is worthwhile.

So that explains why cars have wide tires. What about trucks? Trucks have wide tires to spread the load on the road surface. The road surface can only support a certain level of pressure before it deforms. In maximum road load per axle you can see that many jurisdictions limit the maximum wheel load to 650 or 700 lb per inch of tire width. So trucks have wide tires to avoid ruining the roads.

And finally, as Daniel points out, there is a limit to grip. Oil, water, dirt, and sand all reduce your grip. If you don't have enough grip for the turn you're attempting the result is a fall. Sometimes a rider can stay upright when the wheels are sliding, but it's more a matter of luck than skill.

Conclusion

Pump your tires up to near the maximum pressure written on the side wall.


Tire's won't inflate after winter A few weeks ago I tried to take my Trek road bike for my first ride since last fall. It has been sitting in my (uninsulated) garage over throughout the winter and when I tried to inflate my tires the pressure gauge on my pump showed that they wouldn't inflate. Does this sound like a problem with the pump or the innertube?

Does air leak out when you depress the valve?  If so, air can get in, too, and it's your pump, or at least how you're using the pump.  My old bike pump would act up like this when I pushed it onto the valve stem too far (presta valves).  Could be the case for you, too.


Is gasoline an effective restoration material to use? A fellow rider just picked up an old mountain bike which has some rust and plenty of gunk in the gears to wash out. He intends to use gasoline to clean the entire bike.

This is the first I ever heard of using gas to clean the chain, gears, spokes, pedals, derailleur. Does it work? Save time? It stands to reason it might cut through the grease but can it restore any luster to rusty components?

If no --> the materials & methods YOU use to clean/restore bikes would be appreciated.

also Is there anyway to get rust off the wheels, handlebars, nuts/bolts etc?

Please do not use product names, company names or backlinks in your answer; this is not an invitation for spam.

NOTE "Water, soap, elbow-grease, oil & rubber-protectant" is not an acceptable answer - looking for insight not a statement of the obvious.

Gasoline aka petrol, is a volatile fluid that will dissolve grease and oils.  It will penetrate, soften, and loosen impacted and congealed dirt and dust.

Petrol / Gasoline will NOT fix your rust, nor remove your rust. It will not restore chrome.

Petrol is not terrible for rubber parts, but I wouldn't leave them soaking in the fluid.

The best use for petrol is to clean your parts, before doing a close inspection to decide whether they are serviceable still, or need replacement.

Downside for petrol is that right now its NZ $1.97/litre in my country (approx US $5.36/US Liquid Gallon) and that adds up.  You can't reuse the dirty petrol for anything, and the grease won't settle out so it can't even be decanted.

Petrol is also hard on your skin, so wear gloves, and clean up immediately afterward.  Moisturising your hands before starting is surprisingly good protection too.

Rust

Rust is oxidised iron, which comes from steel being exposed.  Often appears on friction points like chainring teeth, and anywhere that the paint has been damaged letting fresh oxygen to the steel.

There are options:

Leave it alone.  This uglifies your bike and makes it less desirable to thieves, as long as its still mechanically and structurally sound.
Paint over it - this is a very short-term fix and will not last more than a month before the new paint is bubbling off.
Remove the rust then paint it - this is elbow work with a file and sandpaper, or some motorised tool doing the same thing.  You MUST paint the surface within a few hours, else the virgin steel starts to rust again.
Treat the rust - There are many rust treatments which transform red rust into a more stable black oxide of iron.  Most contain Phosphoric Acid and require PPE.  The fumes are something else!  Once the rust has blackened and dried, you can sand and overpaint.

Petrol would be used as a degreaser on the rust before sanding.  Turpentine would be similar, but that's even more expensive than petrol.

Have a look at Suggestions for removal of old chrome?  where I am doing something similar to some handlebars.  That question will be updated as progress continues.


How efficient is string bike? Is this really a revolutionary bike? Bicycles are getting evolved with good technologies or methodologies as the period changes. Now, this one bike, so called string bike has been introduced, which doesn't have chain, derailleur but gears (the website claims so). How efficient this bike will be when compared to the chained ones? Is this one really going to be a game changer? If not, what are all the disadvantages it has?

(this animation says how it works)

The general idea of "lever drive," or a reciprocating pedal motion instead of a rotary pedal motion precedes even the invention of the modern diamond-frame bicycle--consider the Special Star from 1886. More recently, there was the Facet Biocam,  the Alenax, and the Wall Walker.

Within the world of reciprocating drivetrains, the String Bike is interesting in its use of materials (dyneema to transmit power) and the ability to vary mechanical advantage on the lever arm (although the Alenax was able to achieve this simply using hub gears).

But check out what Jobst Brandt had to say about the Alenax. His basic point is that you're converting reciprocating motion to rotary motion, which is mechanically less efficient. I haven't been able to find any studies of the biomechanics of lever-drive bikes.


Can I fit larger rotors on a Surly Karate Monkey fork? I have a Surly Karate Monkey fork that has 160mm rotors.

I'd like to upgrade to Clarks M2 brakes with 180mm rotors.

How can I tell if those calipers/rotors will fit my fork?

You will need an adaptor, but those are common. The only trick is which exact one you need, basically which way you need to move the caliper. The really simple ones just lift it straight away from the mounts like this Hope one:

You might want to move it up instead:

I expect that the 180mm Shimano adaptor is what you want but you should check carefully to make sure the mount spacing is correct.

The process is not tricky, but this blog post explains it in more detail.


What features does a mountain bike need to be converted to an ebike? I'm looking convert a mountain bike and convert it to electric with a rear hub kit. I am wondering what features I should look out for to make this easier:

Is there any way to keep the cassette that comes with the bike or does this have to be replaced? Does it matter if it's a "freewheel" or "freehub"?
Will the front crankset need to be replaced with a larger gear for the higher speeds? Currently looking at a bike with a 40t large gear.
Does it matter which brakes and shocks come with it?
Do mountain bike tires work well at higher speeds or does it make sense to get something less "stubby"?

The cassette and hub will depend entirely on the conversion kit - is it a front wheel, rear wheel or center drive? If rear wheel, you probably will replace the whole wheel with a choice of swaping the cassette over or buying a new cassette.

It might not be possible to install a 40 tooth chain ring on some modern mountain bikes. While the 3x bikes of yesteryear regularly ran 44, its rare for a MTB today to run bigger than 38, and 32 or 34 is most common. The frame designers are probably not considering large chain rings as an important feature in the difficult and crowded area around the BB (on Soft tails).  You would need to check the frame to be sure.

To me, the main consideration is the ability to put an interrupter on the brakes, that cuts the engines when the brakes are applied. This means you will need E-Bike specific hydraulic brakes (Most E-Bike kits have levers for cable brakes with a switch built in). There are after market adapters for hydraulic brakes, but they reply on a stick on magnet and switch.

Knobbly MTB tires work best on soft conditions, slicks on smooth pavement. The E-Bike aspect changes nothing. (Keep in mind an elite rider can probably output more power than a weekend warrior with a 500W motor). Install the tires that suit the trails you ride.


Unable to push oil in when bleeding Shimano brakes I am trying to bleed my Shimano BR-M355 rear brake. This is my first time so it is possible I am making a very obvious mistake.

The issue I am facing is that I am unable to push oil in through the bleed boss. I have tried putting quite a bit of pressure but I am unable to push it in.

Here are the steps that I followed:

Removed the reservoir screw, on the funnel, and screwed in a oil container.
Filled in a syringe with oil and attached it to the bleed boss through a hose.
Loosened the bleed screw, half turn.
Pushed in the syringe with oil in it, attached to the bleed boss.

I have tried loosening the bleed screw further, adjusted the reach adjustment screw so that the lever is as far forward as possible and loosened the free stroke adjustment screw, to no avail. What could be the reason for this issue?

I had opened the reservoir of the front brake caliper instead of the rear.


Is the real world experience of riding a light bike understated by physics-based calculators? Take the case where you have two identical riders, Joe Slo and Billy Whizz. They both weigh 75kg and have identical aerobic threshold power output.

Joe has a 11kg steel audax bike, but Billy likes shiny gear so bought the latest Emonda weighing 5kg.

Physics based calculators (e.g. http://www.analyticcycling.com/ForcesLessWeight_Page.html or http://bikecalculator.com) put Billy about 50m head of Joe after 1km cycling up a 1km hill averaging 5% gradient.

That doesn't sound like much, and not worth spending $5k on.

However, during a hilly sportive the pair will ride 160km including 20km at gradients over 5%, and these are spaced evenly throughout the ride.

Let's assume Billy makes an effort and rides the hills at his aerobic threshold, which is 300watts, and they therefore ride at 20.2kph (http://bikecalculator.com). Joe has to ride at 316watts to keep up (so ~5% above his threshold). That doesn't sound like as much fun.

What would the likely effect on recovery be for the last part of the ride? Does chasing those few additional watts on each climb have a non-additive impact on performance in the final 20km, for example?

I guess my question is, even though Billy would wait for Joe at the top of each hill, does the additional effort required to keep up make this a sufferfest for Joe?

The physics model of cycling power and speed has been validated in the real world. Two examples are this and this. The model embedded in Analyticcyling.com's online calculator is based on these two papers.

Whether the amount of difference calculated by the validated models is worth it to Joe and Billy is a question that can't be answered by the physics.


Why would a frame lack serial numbers? Other than being a custom frame or it was stolen is there a explanation for the frame to be missing the serial numbers?

For instance do they use the same identification marks over seas?

Even if you find the serial number, its absolutely no use in identifying the bike without a brand/manufacturer.  There is no global index like auto VINs.

Serial numbers are used for several different purposes.

Identifying a frame through production, for logistical and tracking reasons
Identifying a completed bicycle through a sales process
Uniquely identifying a bike for warranty purposes
Identifying a bike for insurance purposes.

At no point is a bicycle frame serial number used to identify the bike's model or age or manufacturer.    A frame's serial number is not related to a car's Vehicle Identification Number (or VIN.)

For a frame to lack a serial number could be any or

The frame was hand made by a small-run frame builder, or home made.   Most frame builders would use a serial number of some format though, even though their monthly output could be single digits.
The frame has been repaired and the serial number was lost by replacement.
The frame has been stolen and resold, with the serial number ground off or filled-and-painted-over.
The frame was legitimately repainted and the serial number is obscured or hidden (my bike's like this - the S/N is visible but illegible.
The serial number is covered by an accessory (very unlikely)

But most likely, you simply haven't found the serial number.  Common places for serial numbers:

Under the bottom bracket
On top of the bottom bracket housing
Up the side/front/rear of the  seat tube
Up the side/front/rear of the  down tube
Up the side/front/rear of the  head tube
Inside/outside the chainstays
Inside/outside the seatstays
Inside/outside the rear dropouts.

Less common areas to find a serial number

INSIDE the bottom bracket housing
Down inside the seat tube.

Places you won't find the serial numbner

On any mechanical part - they may have their own serial number, but it won't be a frame serial number
On the fork - again it may have a fork S/N or replicate the frame's SN or it may not have a serial at all
Inside any closed tube - the headtube, BB and seat tube are the only tubes in the frame with some level of visibility, so it won't be anywhere else.


Older Brompton front brake cable I needed to replace the front brake cable on my old brompton, so (after a bit of searching) ordered what I thought was the right cable (QBRCABFA-M[3] from sjs cycles). Turns out, it was the wrong one and the nipple is too small for my brake lever.

As described in this blog post:
http://blog.brilliantbikes.co.uk/2015/05/brompton-10-degree-brake-lever.html
... brompton move away from their own brake cables to a more standard type in 2012.

It seems the old cables are quite difficult to find now, the front cable I purchased was the only one I could find that looked right. One option might be to buy this cable for the rear brake, and cut the cable to the right length for the front...

So, my question is, how can I get round this without buying new brake levers? Anyone have any other bright ideas?

(Pic below shows my brake lever)

Your own posted link says

  Brompton with the 10 degree brake levers with an open clevis should be
  replaced with either the 30 degree or new aluminium brake levers.

Sounds like the 10 degree ones risk the cable's mushroom falling out of the open clevis, rendering the brake inoperable.  That would be bad.

You should replace the levers with safer ones.


Should there be grease in my steel frame's tubes? I've taken apart a road bike from the 70s with a (french) ball bearing bottom bracket. Looking inside I found (what I thought to be) absurd amounts of grease in the tubes coming into the bottom bracket. I'm a bike work beginner and intuitively I would've thought that's excess grease pushed into the tubes, but the sheer amount made me wonder whether it's there intentionally - maybe to seal off the tubes/bottom bracket?

Also haven't found anything on it yet on Sheldon Brown's website, but that might just be my fault.

Thank you for your help.

Some mechanic might have put a liberal amount of grease in the BB shell and also in the head-tube prior to assembly. Then copiously greased the seat-post as well. Grease has a tendency to migrate, especially in hot weather and move to the strangest places, the bike may have been stored upside down, head or tail-up.

Think of it as a gift from whoever put it there, the coating also prevented the tubes from rusting on the inside. Wipe off the excess before re-assembly and repack the BB and the headset with fresh grease. In no case would I use solvent to clean the insides of the frame.


Rust proof or not the outside of a steel steerer column beneath the stem I have a new steel frame which I am building up.  I intend to rust proof this first by using Waxoyl made by Hammerite which I will use on the inside of the frame and forks.

Should I use this on the outside of the steerer column ie under the stem etc?  I am worried about the stem slipping with this substance being oil based.  If not is there any way that I can rust proof the outside of the steerer column?

Thanks in advance.

I generally wipe whatever greasy or oily rag I have lying around at the shop on any uncoated steer tubes as a habit. We're in a fairly dry area so it's not of great importance. If I was in a wet area I'd use a product called FrameSaver.

There is no concern with slippage if the steer tube is greasy.


What do you do when a bus stops in front of you? When a double decker bus stops in front of you, what do you do? Is it safe to attempt to overtake the bus?

The Highway Code comes in handy with this question...

In London drivers of all buses are exceptionally well trained and likely to be highly experienced. They know every part of their route and have 'dealt with' plenty of cyclists before. They will always indicate when they are pulling over and indicate again when they are going to pull out. It is highly unlikely that you will be in their 'blind spot' at any stage of your overtaking manoeuvre.

It all depends on the traffic situation, how much speed you have and how important your journey is. Sometimes you can look through the back of the bus and see how many people are to dismount/catch the bus - if the stop looks like a busy one then you should overtake the bus, in part this is to clarify your intentions to road users behind you that may be 'waiting' for you to overtake before they do likewise. Conversely, if the bus is only dropping off one person, and, if the terrain does not suit you, then it can be advantageous to let the bus go, to 'draft' it and get a good, maintainable tow along the road.

Some bus stops, e.g. on a narrow road with a curve to the left may not allow you to see the oncoming traffic. It may be advisable to hold back in these situations, even if the traffic coming the other way is bumper to bumper. This is because a motorbike or other cyclist may be using the gap between the bus and the cars coming the other way and, once you have committed to overtaking the bus, you cannot duck in to the side again.

There is the Highway Code and you are supposed to let bus drivers pull out. Normal car drivers know this better than most cyclists although not all of them will let the bus out first as they do not want to be stuck behind it. As a cyclist you do not necessarily have the same need to overtake as the bus is likely to be faster than you between stops.

Hence, as a general rule, you should overtake the bus if the general situation is safe AND the bus does not have its right hand turn indicators on. If the bus does have the right hand turn indicators on and you overtake then that is against the spirit of the Highway Code.


What to do with the new parts on an old bike I want to dump? Three years ago I bought a second hand bike, which I used for cycling on average 10 miles a day (mostly commuting). It turned out to have many problems, so over time I replaced many of the parts on it with new stuff: the saddle, seat post, back wheel, tires, crank and back sprocket are all new. Two weeks ago the frame snapped, and given all the problems I've had, I just bought a new bicycle altogether (yay!)

So what should I do with the old bike?!

I want to dump it, but I'm reluctant to throw out all the new gear on it. Unfortunately only the seat post and saddle are compatible with my new bike. I was thinking that maybe I could look around for a cheap frame and use it to make a decent back up bike - but presumably the chances of me finding a cheap frame that's compatible with the wheels and crank and brakes is close to 0?

I live in New York City, so storage space is also a factor...!

Dumping is possible, but dump it somewhere useful rather than into a landfill.

I suggest a bicycle cooperative, who will use your parts to refurb other bikes, or if the parts are completely unserviceable then they will separate and recycle the different metals

A quick google returns these coops in New York, in no order:

http://times-up.org/bike-co-op
https://cargobikecollective.wordpress.com
http://bikecoop.nyc
https://www.bike.nyc/recycleabicycle/

These are not retail shops, instead they are workspaces or groups where riders work on their own or donation bikes.  The coops may be attached to a shop but are separate entities.

Different coops have different "eligibility" parameters for assistance, so it may be worth reading their websites before selecting one.

I know of one coop that limited their "zone" to 5 square kilometres (a city of ~100 square km)  and excluded assisting anyone who owned a car.

Another thought is that a donation to a registered charity may have tax benefits for you.


Lower tire pressure on wider rims? For a given tire width, can you safely run a lower pressure on wider rims?

Background:

My road bike can only fit up to 23 mm tires due to frame clearance, however my rims are a relatively wide 23 mm. So I was wondering if I can run a lower tire pressure than normal for a more comfortable ride without pinch flatting or damaging the wheels on bad pavement.

Running 23 mm tires on a rim width of 23 mm is insane -- your tires should be around to 40-50 mm.

To summarize Sheldon Brown's page:

Narrow tire on wide rim = pinch flats + damage from road hazards (which is the case you are in)

Wide tire on narrow rim = sidewall damage + rim failure and bad handling

You need to get a narrower rim for the bike (or possibly do a 650b conversion if possible, so you can run decent sized tires).


Trek T-900 Tandem rear hub I have a Trek T-900 tandem that I bought used.  It's probably about 12 or 13 years old.

I'm having some rear hub issues with it, but I can't identify what hub it is.  Trek's website and other searches just say "Alloy Hub".  I don't even know for sure if the spacing is 145mm or not.

I'd like to identify the hub, because it needs a new cone.  If that's not possible, I'd like to verify the spacing (I don't have calipers) so I can have a new wheel built.

I've verified that the hub spacing is 145mm - standard for a tandem.  The hub on the bike is unmarked, unbranded, and Trek's website simply lists it as "alloy hub".  It appears to be a 135mm hub with a longer axle and spacers in place.


What features are useful on a bike for carrying children? See also this question: What should I look for in a "trailer bike"/"tag-along" bike for a child?

I want to buy a bicycle.  I will want to use a child seat for a few years, and then move to a trailer.  I will be using the bike in a small UK town in light, orderly, traffic, to travel a few miles (At most 5 miles per journey.) on mostly level ground.

What features should I look for when buying the bike?  What features would be useful?

What features are less useful?

In the Netherlands something has evolved that is (unofficially) called the "mammafiets" or "mothersbike" main features that make it a useful bike for cycling with children are:

A larger distance between the saddle and the handlebars to allow plenty of room for a child seat on the handlebars.
Wider handlebars to make it easier to reach around the kid in the front-seat, and to make steering with a kid in the seat easier (more leverage) and the ride more stable.
A support stand that has feet on either side of the frame to make it more stable when parking
A steer-lock to keep the front wheel straight and stable when your kid is in the front child-seat when you park the bike (very easy when loading a second kid on the back-seat or when opening shed-doors, etc.)
A lower saddle to allow you to reach the ground more easily with your feet
A slightly longer rear luggage rack to give the kid in the rear-seat a bit more room, and still allow for panniers.
An extra low step-through frame.

This is a typical example:


Double-walled rim's what difference depth makes? Provided both rims are double walled aluminum, what advantages/disadvantages of having deeper 30mm rim vs more narrow 18mm depth?

EDIT: I am not Tour de France type of rider, not setting world record in speed, more of commuter, most of the time i am cruising in the city streets and sidewalks.
Used to think smaller depth rim has less weight and this could be advantage for cruising (not high speeds) compared to deeper heavier aluminum rim also its more flexible so it could be advantage as well for bumps etc?
P.S. I do have a 700c retro skinny frame bicycle.

Strength, and image of aerodynamics. A deeper rim is stiffer and can get away with less spokes or sloppier build than a low profile rim. Aerodynamic wheels have typically deep rims, and all deep rims get part of the glamour, even though bad design can make a deep rim just draggy as a low profile box section rim.


Replace a Sachs Echo s with modern derailleur enter image description herelooking for a replace of a Sachs Hurret Echo S   with a modern derailleur for use on a 14 28 free wheel.  Suggestions have been the Shimano Altus or Shimano Tourney neither actually work as lower cage hits the spokes when shifting to the large rear cog.

Bicycle is a Peugeot 80s racer 12 speed  -

Any suggestions for a basic replacement that works very welcome -

Thanks
Stephen

Freewheel 6 or 7 speed wheels typically have no clearance problems there. The issue is likely being caused by rear derailleur hanger misalignment and/or the low limit screw being adjusted too far out. There are many questions about both.

Update post-image: The derailleur hanger is bent. Put the shifter in high position and poke a 5mm 3-way wrench or  L-wrench into the pivot bolt of the new derailleur. Reef it around to make the plane of the pulley centerlines appear parallel with the plane of the cogs. Re-adjust the high limit if needed, double check it looks parallel, and you should be good. Eyeballing like this isn't great for latte speed generation bikes, but it's fine for 5 and 6 speed. If you want to baby the frame you could have it done with a proper tool, which I'd recommend in most other non-emergency cases.


Ideal top tube length for BMX Regarding BMX bikes, is there an easy way to determine what top tube length is most suitable for a person based on their height?

In my experience, most LBS only want to talk about BMX size in terms of wheels ("it's a 20 inch" or "it's an 18 inch) since they're mostly considered to be kid's bikes.

This is the tool you're looking for:

https://www.ebicycles.com/bicycle-tools/frame-sizer/bmx-bike

It's not a linear calculation, but it would be fair to say that a rough estimate is: start with a 22.5" top tube for a 6' adult male, and add/subtract half an inch of top tube for every inch of height.


Magura rim brake does not work well on a new rim I have a bike with 20inch wheels and Magura HS11 rim brakes. On the rear wheel I have just replaced the rim, because the old one had split after many thousand kilometres. The new rim is an Alex  DM24 406X24. The old one was another wide aluminium rim.
The Maguras were braking fine with the old rim. In contrast now with the new rim the brakes do not work well: After some initial moderate stopping power the brakes do not grip harder when I pull the lever harder.
To explain it a bit more in detail: When I press the lever slightly (say, of a “feels-like’ amount of 10%) the brake reacts as expect by braking of “10%”. But when I press hard, say 50% or 100% (=as hard as I can), the breaking power does not increase at all, it stays at around 10%.
I am pretty sure it is not an issue with the brake system (oil, etc), because when pulling the lever I feel that the pressure against the rim increases. (Furthermore, not oil is leaking out and the brake behaviour is consistent over days.)
I guess it must have to do with the brake pads an the rim surface. The rim looks to me like it has normal alloy sides, so I kept using the old black brake pads.
So, what might cause this strange behaviour? Should I replace the pads with pads of another type? Or is there another fix?

As it turned out, the problem were not the brake pads. The issue was cause by the fact that the new rim is slightly  narrower. The brake cylinders still touched the rim, but were the already nearly fully extended out. This lead to the particular situation that the brake started breaking lightly, but full force coupled not build up, because the two cylinders had reached their maximum extension before that.

The fix was easy: I moved the brake cylinders (in the released position) further in and now they are gripping the rim again properly.


Can I install a handlebar brake handle without removing the grips? I recently bought a cruiser bike with coaster brakes. I decided I wasn't happy with the stopping power, so I want to add a hand brake to the front wheel.

I ordered some parts online, but I have run into some trouble with installing the brake handle. It doesn't open wide enough to attach at any point to the handlebars, it appears that I have to take off the handlebar grips and slide it onto the handlebars.

But it's a new bike with new leather handlebar grips that I'd rather not ruin. I've seen some videos online about removing grips with Pledge and a screw driver, but that seems kind of iffy to me.

Do they make a handlebar grips that attach similar to some phone mounts that I've seen, where they open up wide and then screw shut?

Many BMX levers are hinged, so they don't require messing with the grip. These can be had for either short pull (canti/caliper/u-brake) or long pull (v-brake/mechanical disc), so make sure to get the right pull. They're intended for one or two finger use.

Various basic "touring" levers, of the stamped sheet metal variety, also go on and off without removing the grip. Some, as in the currently made/available Sunlite one pictured below, have little clampy bits that detach and then are slid back into place, and others have a steel band clamp you can open up to bend around. These generally aren't the nicest brake levers, but they work and may match the aesthetic of the bike better.

FWIW, most nicer modern hydro levers have either a hinge, faceplate, or other scheme to allow this as well.


Saddle or frame shape for painful Coccyx? As a child I was very active, and in a weight-lifting injury I damaged my Coccyx, making it very difficult to sit in the same position for long periods of time. As such, bicycling, what once was a staple joy in my life, has become painful. Is there a seat or frame design that takes pressure off the tail bone so that I can ride pain-free once again?

A good seat should put most of the pressure sitz bones rather than the tail bone. You'll probably want to look for something like the Rido Saddle which has the back cut out and would probably minimize pressure on your coccyx. I can't say whether this type of saddle would work well for you, but in my mind it seems like it might do a good job.


Early Klein Mountain Bike - need suggested component rebuild ideas This classic ride, (a hand-me-down, no less,) has served me well for more than a few years. The componentry is showing its age and the drivetrain really needs to be replaced, but I can find no specs on the BB threading or the rear fork width (if that's the term) so I can get the right upgrades. I'm planning to use this stunning contraption to commute to work, which combines mostly suburban-urban streets with a little dirt thrown in.

Can anyone help me find specs on this wonderful ride so I can hit the road when the warm weather kicks in? Much appreciated.

I think you're going to have to pore over photos and Klein fan-sites like oldklein.com to find the specs, answering one question at a time.

In terms of the BB, I believe they were press-fit bearings, in press-fit cups (like an old BMX), so you might have to remove them, measure them, and then approach an engineering supplies shop for replacements. Bearings are surprisingly universal so don't be put-off too easily by people saying "ah they are proprietary Klein bearings, forged by Klein faeries from Klein precious metals".. they are probably available!

The rear hub width can be measured easily by you, it's probably 135mm but that's a guess. Things like cranks will be square taper LX types, maybe something oddly 90's like bio-pace oval rings :)

I can't guess the model, but I don't remember the Pulse or Attitude havign internal top cable routing like that, so is it an Adroit? If so, I'm pretty sure they aren't the original forks.

Let us know how you get on! Lovely bike, I lusted after Kleins when I was 15!


How to define if brake pads suitble for carbon clinchers I have Carbon Tubeless wheels ZIPP 404 Weaponary 10 speed, which I have bought on my used Pinarello Ultegra rim brakes.
Now I hear that Carbon wheels should / must have special brakes.

Question is: How do I determine if I have right brake pads? and

Is it MUST to be special pads for carbon, what if not?

Yes, you need special pads. Every manufacturer of carbon rims has their own recommendations for what pad to use, which you should follow. Zipp makes their own pads.

Normal brake pads are harder, and can wear away the carbon rim surface. This is very bad, of course. Brake pads for carbon rims are softer and wear down more quickly so that they preserve the rim.


How much pressure to inflate a tubeless tire so it seats into the rim I want to set up my tires tubeless. I got a Schwalbe Tire Booster and have a proper air pump as well. The booster is capable of holding up to 11 bar of pressure. I am not sure how much pressure I have to put in there to initally inflate my tire so that I seat the tires (with a pop). I guess there are differences for tire size as well. All I could find searching the net was a hint of a mechanic to not go over 40 psi.
I have a 650/47 tire and a 700/42 tire but for the community it would be best to have an answer that fits for all possible combinations like a list or so.
Anyone who can help out here?

TLDR: The pressure you put into the bottle is NOT the pressure to which you inflate the tyre. The pressure drops down as the volume increases when you connect the bottle with the tyre. The final pressure you inflate your tyres to is mostly personal. There are some guidelines but depend on many details about the terrain and the tyre properties.
You ask for a list for various tyres. I do not think that is necessary at all for the reasons I mention - at least for the pressure of the bottle. Small tyres can withstand larger pressures and larger ones will not reach high pressures due to their volume. You can always try with 5-7 bar in the bottle, but the maximum the bottle allows should be safe for most tyres I can imagine.

If your tyre is above 40 mm, as you indicate, and of typical max pressure limits, you should have no problem using the maximum pressure indicated on the bottle if necessary.  There are about 3 litres of air in the 45 mm tyre. The bottle has 1.15 litres. That means the final pressure in the connected system will be around one quarter. You may want to go lower in your first try, if your maximum tyre pressure is unusually low.
I use 10.5 bar (622-38 tyre with indicated max of 70 PSI) or slightly less when pumping becomes too hard with my body weight (but I want around 10 bar to be sure). You can of course first try if less will be enough for you. You may well be lucky with 5 or 7 bar, and it is dead easy to just try that first. Don't worry, it won't harm anything if you use too little. The only thing that may happen is that the tyre will not seal and you will have to try one more time with more pressure.
You will not reach that pressure in your tyre anyway. You distribute the pressure in a much bigger volume (bottle + tyre).
You first remove the valve core, connect the bottle and let the air in. You will then have to disconnect the bottle, put in the valve core (it is foolish trying to boost the tyre with a valve core - yes, I tried) and you will loose A LOT of pressure when doing that. After that you will have to pump up your tyre with a pump, because the pressure that remained will be quite low. It is only then when you care about the recommended pressure for tubeless riding in your tyre.
Nevertheless, when seating the tyre I go above the pressure I ride at (in the final stage with my floor pump). I let it first pump to 50 to 60 PSI. Then I ride at 30-40 PSI. The official range when using tubes is 45-70 PSI (3-5 bar) for my tyre but tubeless allows less.

For more general advice you can see other resources like How To Choose The Right Tyre Size For Gravel: From Road To Off-Road Riding but really, it is mostly trial and error on any combination of rims and tyres and there is a lot of personal preference involved. I like small tyres for comfort off-road. If you only ride on smooth tarmac you will choose higher pressures than if you ride on cobbles or on gravel. For road tubeless bikes I would be more careful about the range the vendor specifies, but for larger tyres it is really mostly trial and error. The more it is off-road, the more it is so. For mountain bikes you are looking for good traction and good suspension but at the same time you must limit burping.

A final remark: some tyres behave strangely. Mines (Schwalbe G-One Allround) are easy to seat using a floor pump when new. However, after several thousands of km, they became softer and it was not possible to seal them in any way and I had to buy the bottle. Now I bought a replacement for the front one - it was not possible to seat it with the booster, it was too stiff and when the booster was disconnected, it quickly unsealed. But it went easily with a pump. The old rear tyre, however, required the booster and was impossible to seal it with the pump...


Replacing 1x SRAM chainset with a Shimano chainset I've just got a Genesis Datum 2019 bike on clearance.
The spec wasn't exactly what I would want—for a start it has SRAM rather than the Shimano we have on other bikes in our household—but more importantly it has 172.5mm cranks whereas I have reduced hip mobility and 165mm cranks are much better for me.
I therefore need to swap out the chainset, but wonder if it's possible to switch over to a Shimano chainset at the same time?
Since this is 1x, there is no front derailleur compatibility to worry about, just the chain and the bottom bracket. I assume the chain will be fine, since Shimano and SRAM 11-speed cassettes are inter-changeable.
So then it's just a question of the bottom bracket, which I suspect won't be compatible.
I'm quite used to doing maintenance on bikes, but so far I've been lucky to only work on BSA threaded bottom brackets, with either square taper or Hollowtech II cranks, so don't know anything about the press-fit type (86mm shell width, I understand) on the Datum.
The same frame has been sold with Shimano's BB-RS500-PB bottom bracket, so presumably if I get this and a 165mm Shimano 1x chainset I will be good to go?
Or will a 1x Shimano chainset work with the BB used by the SRAM chainset?
And are there other compatibility issues I need to worry about?

Unfortunately, the bottom bracket compatibility is an issue.
The Genesis Datum appears to be a gravel bike, mainly sold in the UK. Here is one retailer page containing specifications for a 2019 Datum with SRAM Rival 1x. If this page is correct, you have a Rival crankset with a GXP spindle.
Shimano's cranksets use 24mm spindles. GXP, a standard specific to SRAM, uses a stepped spindle that's 24mm in most places, stepping down to 22mm on one side (I forget which). The bike is listed as having a SRAM bottom bracket, so I'd presume this is a GXP bottom bracket. You can easily adapt a Shimano BB to GXP with the use of a spacer on the 22mm side. If you do indeed have a SRAM GXP press fit BB, then you can't adapt that to a Shimano crankset.
You would need to have someone press out the BB and install a new one to make the Shimano crankset work. You would look for a BB86 bottom bracket. However, note that all BBs are made to accommodate a number of spindle diameters, and you have to specify the spindle type as well as the BB shell type. There are straight 24mm (or similar) spindles and 30mm (or similar) spindles. One issue arises with the "or similar" bit - SRAM have gone to a spindle standard called DUB, which uses a 28.99mm spindle. This gives more room for seals and bearings, and they believe it improves durability versus a 30mm spindle, especially on some BB standards; however, you can generally find reducing spacers to adapt BBs for 30mm spindles to the DUB spindle. The fact that you need to specify two separate characteristics is initially confusing. However, you would specify something like BB86 24mm or BB86 Shimano to look for a BB86 for a Shimano-style straight 24mm spindle. BB86 30mm would pull up results for bottom brackets that fit your shell but are too large for your intended crank.
So, if you were getting a new SRAM crankset, you would need a DUB BB. Your possible options include:

If you intend to mount a Shimano GRX 1x crank, you'll need a BB compatible with Shimano spindles. Aside from that, you should be able to simply swap the cranks in. There shouldn't be any material issues with the chainline, and the chainrings will be compatible. If you are using a standard Shimano road double crank, then the chainline may not exactly match SRAM's intended 1x chainline, but the difference may not be material.

You could find 1x GXP crankarms or a whole 1x chainset in your desired length, whatever the model. SRAM is moving away from GXP as a standard. It's possible that this may impact the availability of new parts, but I think Rival hasn't transitioned to the DUB BB standard yet. It's possible that people are looking to sell off their old GXP stuff. You might consider adjacent models, e.g. Apex cranks. You should be aware that some SRAM cranksets might have 30mm spindles, usually suffixed with BB30. If you get one of these, you'll also have to change your bottom bracket.

I would normally assume that if Genesis specced Rival, they would have used the Rival GXP press fit BB. If they somehow used the Shimano BB with a spacer with an otherwise Rival setup, then you can ignore what I wrote above. However, I don't see this as likely. Component manufacturers offer favorable pricing based on bulk buys. It seems a bit unlikely that Shimano would have offered Genesis good pricing to buy a bunch of orphan RS500 BBs, and Genesis would still have to had to source spacers.


How do you measure the length of a loose spoke? I have built up quite a few old spokes, which are all perfectly useable. All I need to know is their intended length, but I am not sure how it should be taken.

Generally speaking, the unstretched length of a spoke should be measured from the inside of the J bend right down to the far end of the spoke.

Your best tool for doing this is either a metal ruler where the 0 measurement is right at the end of the steel, or a normal ruler with a notch filed in the end, down to the 0 line.

The best method is to hook the J of the spoke over the end of the ruler, and then read off where the other end falls.  Accuracy to the millimetre is fine, no need to go any more precise.

Here's the Park SBC-1 which does exactly the same thing.

Since spokes are sold in metric lengths, you'll always use the metric side.  See how the J is hooked into the hole at 0?  This one is about 268 mm long.

Another method is to simply bunch the spokes in a fist and push the threadded end against a flat surface.  The longer spokes will poke up more.

Things of which to be careful:

the amount of thread rolled onto the spoke could be different between types
the thickness / gauge of the spoke could be different, giving it different flex characteristics which could move load to this spoke, or away from this spoke
Gauge of nipples should match gauge of spoke too, else they could back themselves out over time, or make tensioning harder.
Finish - spokes may be galvanized, chromed, blacked, or coloured.  Some riders care about this kind of thing.
Set - a used spoke will subtly vary the J bend at the hub.  This can stress the used spoke and make it snap easier.  It can also sit differently in the hole, and may adjust over time causing the wheel to untrue erratically.
Nipples - have a defined tolerance for damage.   If anyone has monstered the nipple with the wrong size of spanner then it may be hard or impossible to tension the wheel right.  If possible reuse the nipple from the broken spoke, assuming its serviceable.

Personally, I have no problem reusing an undamaged salvaged spoke.  I've also rebuild a whole wheel onto a new hub reusing all the spokes in that wheel.   However none of these were high performance wheels being pushed hard.

Use your best judgement of course.


I removed the drop-out adjusters... Do I need to adjust my derailleur or add chain or both? I have an old 1998 Lemond Zurich, and I recently purchased new wheels. The old bike had drop-out adjusters. When I added the new wheels I felt like my bike was rubbing against the brakes, then all of a sudden the rear wheel was dislodged and started rubbing against the chainstay. After the ride, I found the dropout pins (adjusters) spring were old and unaligned. I was able to remove the drop-out adjusters, so I'm hoping that fixes the problem and the wheel does not fall off again. However, the wheel sits a good 1 cm further into the drop outs. Could this new position effect shifting? Do I need to add chain links? I'm not interested in knowing why my wheels are falling out, just whether I should adjust my chain or derailleur.

So you might be about two links short, or you could move the wheel forward. The purpose of the adjusters is to make it easy to position the wheel. The tension on the quick release skewer is what actually keeps the wheel in place. From what you describe it sounds like the skewer wasn't generating enough tension.

Try this:

Locate the wheel where you want it – I'd put it where the old wheel was.
Adust the quick release handle so that it is pointing strait out, parallel to the axle (perpendicular to the wheel).
Tighten the adjusting nut on the skewer until all of the gap is taken up.
Press the lever home into the closed position – it should take some force. If you can't get it to go parallel to the chain stay, then back off the adjusting nut. Just a little bit, maybe a quarter turn, and check again. Don't be afraid to push reasonably hard, the lever should leave a bit of a mark in your palm.

If you do that, the wheel should hold where you put it. You might want to put the adjusters back in. They will help get the wheel in the right place, so you won't need so many hands to install it.


Cito bicycle history / old steel bike identification I have a Cito Master Star bicycle but cannot find any info about it online. I think it is a 1969 model as it has a 69 stamped onto it. It also has aero coronado cranks but has some belt drive system I'm not familiar with. Any info on it would be appreciated. Thank you for all your replies so far.

That is a unique-looking bike.
The seat stays appear to be bolted on top and bottom, which is how a PO was able to fit a belt without cutting the frame or using a split belt.  That it has track ends rather than a dropout suggests this might have been a track bike in its early years.
However track bikes generally don't have brakes for track use.  It is possible the same PO fitted the front hub brake (wise move) and uses the fixed gear rear hub as the back brake.
The belt drive system is a relatively recent addition, and I guess this frame was selected because of the rear stays.   I can't find a "coronado" crank with belt drive, so its possible this combo is an aftermarket replacement of traditional chainrings with a single drive belt spindle.
The rear hub appears to have a "pull chain" hanging from the side and tied by string.  This could be a way of making an IGH into a single speed ?  Seems dodgy to me, I'm not sure if an IGH would like being locked up for rear braking, or more likely this bike only has a single brake and the rear coasts.
The head tube angle looks very "reclined" compared to more modern designs.  I bet this bike is easy to ride no-handed due to the slack angles.
Obviously the handlebars are a replacement - this bike would have had drop bars or track drops originally.  The saddle is definitely much newer too.
Lastly, the tubes appear to have a Woods or Dunlop valve.  These have become less common globally, other than China and the Netherlands.  I would also suggest looking closely at the tyres for dry rot and cracking, for safety, they don't look new.
All in all, sweet bike and you'll enjoy riding it.   If it were me I'd fit a rear brake, connect the IGH to a shifter, and possibly go back to drop bars.


Front derailleur adjustment I need some advice on properly adjusting the front derailleur (shimano -tourney) of my bike.

I did watch youtube videos and stuff on the internet but was not able to adjust it properly.

When I attach the wire to the derailleur, either derailleur becomes too tight or too loose, making the gear dysfunctional. Though I tried to fine tune through the two screws, I was unsuccessful.

Any video or any recommendation is highly appreciated.

Thanks

The small chain ring is considered the first gear, so it goes 1-2-3. The derailleur spring pulls the derailleur always towards the smallest chain ring, which makes sense if the cable snaps during a ride: you could still get home without having to walk your bike on hilly terrain. If it was always on the big chain ring, you would need some serious legs depending on your local hills.

Did you ever check a Shimano manual regarding the front derailleur adjustment? They explain very well what you have to do in detailed steps. But if you can't get it right using the mentioned Park Tool tutorial, i would really recommend visiting the LBS.

What i am missing in the Park Tool tutorial is the step where you have to loosen the inner wire. This should be "Step 0". The wire has to be loosened while adjusting height or rotation of the derailleur.


Hydraulic brakes accidentally oiled Please help me. When I'm using my hydraulic brake I hear a weird sound. I think putting oil on it will cure the problem but I guess it just come out worse. After putting oil my brakes they are not working. How can I fix this?

Braking surfaces (pads, rims, rotors) must never be lubricated in any way. Doing so can severely affect braking performance and is dangerous.

You can clean the rotor with isopropyl alcohol or mineral spirits.

The pads will probably have to be replaced as oil permeates into the pad material. You might be able to save them by cleaning with alcohol and sanding off the top layer, but replacement is the safest option.


ergonomically sound seat types or features? Are there seat types or seat features that are ergonomically better for certain kinds of ailments such as lower back pain, knee pain, etc.?

For example, perhaps cushioned seats might be better for absorbing shocks from the bike or firmer saddles could be better for stability.

Yeah, seat height and fore/aft position (and handlebar position) are more important than design.

Seat height is especially important for knee pain -- having the seat too low is quite hard on the knees (as is pedaling in too difficult a gear).

For the back, seat position fore/aft and handlebar position (both up/down and fore/aft) determine how much the back is stressed.  Generally a more upright position (seat and handlebar closer together and handlebar higher) is easier on the back, but seat and handlebar too close together can "scrunch up" a tall person and cause problems.  (And if you have an excess of avoirdupois having the handlebar too low can make it hard to breathe well.)

The main thing that seat design can do for you is relieve (or not) pressure on sensitive areas, indirectly relieving the back since you don't contort yourself so much to take pressure off the sensitive areas.  But it often turns out that super-padded seats and (especially) seats that are extra wide are less comfortable than their more Spartan cousins.


My chain on my 9 speed is slipping My chain on 9 speed is slipping. I measured my chain but the slipping continues.

By the look of things, you may have the cable a very little bit too tight.

In other words, after you have gear down, the cable is still pulling just enough to want to go further (in the direction of the spokes), which causes the chain to ride up on the gear teeth.

Adjusting the cable adjuster (sometimes it's located right where the cable meats the derailleur) a 1/4 turn to loosen (make longer) the cable, should be enough to drop it back over the teeth.

This off coarse is assuming that by your description the cassette and chain are not worn or have not be independently replaced.


Plastic taste in my backpack water bladder I've seen various suggestions as to how to remove the nasty plastic taste but it still seems to be the overriding taste.  I've tried bleach, vinegar, lemon juice, water purification tablets, bicarb.  I'm almost at the point of giving up and assuming that I'm ingesting carcinogenic chemicals. It isn't branded like camel-back etc.

If anyone has any other suggestions I'm all ears.

Denture cleaning tablets - they leave a nice minty taste as well.  Locally we have a brand called Steradent (UK & Aus only by the looks of it) that I use to clean out bidons every once in a while to get rid of either stale or detergent tastes.


The lever came off my thru axle. Now what? I have a bike with a 15x125mm thru axle at the front. I tried to unscrew the axle, but only the lever unscrewed (detached completely), leaving the axle in the fork. This leaves me with two questions.

First, how do I remove my front wheel now? The axle does not have an allen key socket, or any other way to remove it, as far as I can see.

Second, if I figure out how to remove it, how would I replace it? Will any 15x125mm axle do, or is there something to consider beyond dimensions?

https://www.planetx.co.uk/i/q/WSBBB/on-one-bish-bash-bosh-frame-axle

Does not sound like a great design, presumably the lever was supposed to be tightened onto the axle body tighter than the axle in the fork.

Two possible methods to get the axle body out:

Use a threadlocker such as Loctite to bond the lever to the axle body. There are two kinds of Loctite: Blue and Red. Blue is weaker and designed for preventing fasteners vibrating loose. Red is stronger, designed to be more permanent and is loosened with heat. Red may be appropriate in this case.
Find a bolt that fits the internal thread of the axle body and a nut and washer that fits the bolt. Put the nut and washer on the bolt, screw the bolt into the axle (in place of the lever) tighten the nut against the axle as a locknut (with the washer between the nut and axle to protect it). Hopefully when you back the bolt out the axle with come with it.


What thread does the b-screw on a shimano rd-6400/6401 have? What thread does the b-screw on a shimano rd-6401 have?
I need to recut the thread but am not entirely sure if it's an M4 fine pitch or something else.

I have in front of me an RD-6500, Ultegra 9s rear derailleur. The B-screw is an M4 x .75 pitch x 12mm length. Looking at a couple older shimano derailleur's, it appears that the B-screw is also an M4.
Shimano's website has various technical documents, some of which are "exploded view" diagrams of the parts that make up the part. At the bottom is the list of the parts, and when it's a fastener, they often give the size and length of it. However, the exploded view of the RD-6400 does not have the size of the B adjust bolt. Here is the EV of the RD-6500 which does list the B-screw as an M4 x 10mm.


Can Inner tube 1.25 / 1.5 fit 26x1.4 tire? I have a tire 26 X 1.4 what size tube should I buy for it? 1.25 or 1.5 Inner tube ?

Most 26x1.25 sized tubes are rated from 1.25" up to 1.5". You should be fine with the 26x1.25 tube as long as that's the lowest size indication on the tube.

Though most tubes you'll find will indicate an acceptable low/high range. You're likely to find the tubes indicated as 26x1.25/1.5 which should fit any sizes listed or between.


Can a tubular tire be reused? I have some knobby cross-specific tubular tires (Challenge Limus 33) mounted on a bike and I want to change them in exchange for slick tires for a period of riding primarily on the pavement.  While they are excellent tires, and have a lot of life left, the road noise is undesirable.

Can these tires be reused after they have been separated from the rim tape and/or glue?

Yes, you can reuse them.

Just be careful removing the old ones, clean them up and then swap on the new ones.


Where can I find Cannondale bike's serial number if the sticker is missing? I was looking at a used aluminum frame Cannondale from 2017 but the serial number sticker is missing:

Cannondale bikes will display the serial number on the underside of the frame. It’ll be next to a bar code.

Source: Cannondale registration pgae
I was wondering if the serial number can be found somewhere else on the frame in case of a missing sticker. I have seen it stamped below the bottom bracket in other brands' aluminum frames, but not on this bike.
Thanks for your help!

I heard back from Cannondale support. The sticker is the only way to know the serial number on their newer bikes:

No, the serial number is not stamped on the frame. It is underneath the bottom bracket on a sticker with a bar code, 2 letters + 5 numbers.


Need help with BMX Frame logo stamping I need help with this logo, I cannot find any clear answers... The frame is aluminum, the rear dropouts have this logo stamped and the bottom bracket does have two sets of serial numbers.

Possibly a THRODWN. The BMX brand was started in 2015.


MTB front and rear shimano derailleur: which shifters for drop bars? I would like to convert flat bars of my MTB (old one: ATX 770 Giant, 7 speeds cassette with Deore DX derailleur and 3 chainrings crankset with probably DX as well) to drop bars, for touring purposes (I do not want STI shifters, and even less rapidfire system).

I am running into the following problem:
- Are Dura Ace downtube shifters compatible with the MTB derailleurs? If yes, how can I possibly set them up on the bike?
- OR would you think Deore XT thumb shifters somehow mounted on the drop bars are best (I guess it could be a bit tricky on a 40cm wide drop bar, with the necessary front light mount and handlebar bag mount)?
- OR do you think this is all silly and I should get a proper touring bike?

I think it's silly and you should get a touring bike. However, if you run Dura Ace with those derailleurs, the front derailleur will work like normal. For the rear derailleur, you'll have to give a little slack and instead of pulling it straight out to pinch, you have to bend the line to a 90 degree angle and then pinch. If you have more questions, check out Sheldon Brown's website. http://www.sheldonbrown.com/


Will hydraulic brakes work with vertical underseat recumbent handlebars? I have this type of recumbent. I want to upgrade to hydraulic brakes, but every bike shop warns me about the issues that will come from attaching the brake levers in a vertical position. They say that it will catch air very quickly. Do I  have any options? Maybe there is special brakes for this type of situation?

I can't speak for every hydraulic brake ever, but when I've done this I didn't worry about it, I just bought sealed brakes and put them on. I'm currently running cheap Shimano ones on my touring bike and have not had any issues, and in the past I used Hayes with similar lack of problems.

This bike I switched from cable to hydraulic after cooking the brakes on a downhill, and I haven't had any problems in about 5000km of riding since.


What is the purpose of suspension lockout? I'm trying to decide which 29er bike I want to purchase and one of them has lockout. I know what lockout does but I'm not sure what it is used for and if I will need it.

Thanks

Update: We're good now. It's been 6 years (Holy crap) since I've posted this. I'm definitely fully aware of lockout. I've also realized my Rockshox Recon Silver lockout is actually 100% lockout since there's a buffer.

You turn it on when riding on smooth surfaces or going up hill to improve pedal efficiency.  It's hard to know if you will need it in advance because without riding the bike you won't know how well the suspension design handles pedal bob (the energy lost by the bike suspension compressing under pedal forces), try and get a test ride.


Just curious what DIY setups have worked for removing crown race from a steerer tube? I have a great solution for installing a crown race with just plain PVC pipe, but am really flummoxed as to how to remove a crown race from carbon forks without purchasing a specialized tool or driving 30 miles to my closest bike shop? Any DIYers out there that have found a consistently workable solution? One that does not involve flat-blade screwdrivers...

A method I've never loved but have used a time or two and seen others use a lot is an old disembodied pocket knife blade and a hammer. Carefully tap it in along the spine at multiple spots to wedge off the crown race. This method does work well, including on forks that offer zero overhang of the crown, but it has some risk of cosmetic damage in the best case, and on a carbon crown I'd worry it might be capable of doing more. You could mitigate that risk by using a thinner blade, probably.

I kind of hate the idea of using this approach on an all-carbon fork (as opposed to an aluminum crown), but the truth is that proper tools work on a pretty similar principle in these days of zero crown overhang being common, and themselves are not totally free of any risk of damage even if used carefully, so it may not be as stupid as it seems. On an aluminum crown you can do it all day as long as you don't care if it looks pristine.


Why don't road bikes use v-brakes? In my experience, linear pull brakes (v-brakes) have more stopping power than other types of cantilever brakes (let the flames start ;). Modern road bikes always come fitted with dual pivot brakes. There isn't a massive difference in weight (Similarly priced XTR v-brakes @ 400g (F&R) VS Dura-Ace dual pivots @ 314g (F&R)) so I'm wondering if there is another reason why road bikes don't use linear pull brakes?

Is it to do with 'feel'?
Are my road
brakes rubbish, and most sets are
actually as powerful as v-brakes?
Obviously, current road levers
wouldn't work (well) with v-brakes..
Is it a pure legacy reason that
v-brakes aren't used?

It may be tradition, and it may be aerodynamics.   Note that some roadsters do... Touring bikes have gradually been switching from the traditional cantilevers to V-Brakes.  It's for tire clearance mostly.
"Good" caliper roadster brakes are very powerful; A set of high-end Shimano jobs (105 or above) will lock your wheel and they are routinely used by pro road racers.
They have a minimal aero profile and contribute little drag.  They also look good on a sleek roadster.
Also, you don't have to weld or incorporate lugs onto your snazzy carbon-fiber fork legs and seat-stays, which results in a "cleaner" appearance and less weight as well; high-end roadsters are all about weight, as you likely know.