General Cycling Discussion - Heavy-duty rims?

A friend bought a Raleigh hybrid bike in an effort to get in shape and lose weight. He's very dedicated so far but has broken two spokes on the rear rim in the first month. He's presently 320 lbs. Does someone make a heavy duty rim and spokes for those who weigh in the 300+ range? We do all our riding on rails-to-trails.

Check with your LBS and maybe they can build him a set of 36 spoke wheels.

As dmac49 stated. Also the Clydesdale forum can further clarify some specific things to find in a rim. There are any number of options. Your friend should find a setup that works very well for him.

What kind of rear hub does your friend have?

If it's a Shimano cassette hub I'd suggest laceing a Velocity Dyad rim onto it. Dyads are commonly used as tandem rims. I wouldn't be overly concerned about using only 32 spokes with a quality build job.

If it's a no-name hub or a freewheel hub I'd suggest replacing the hub also. If you're buying new and durability is the primary concern, you might as well go with 36 spokes.

Try a Velocity Deep V or equiv 30 mm rim. Very strong design. I use them on my tandem supporting a 400lb+ tandem team.

Not sure my touring bikes rims are geared for 320 lbs of rider, but I had my touring bike upgraded to A719 Mavic rims in order to carry more weight for touring. My new set was also double butted spokes and a heavier gauge. Before under load i was constantly braking spokes. Afterwards, I might carry 45 lbs of weight on tour. It seemed to work out much better. Should the gap in your friend's brakes be insufficient they make not work.. The gap on most touring bikes are wider than on road bikes.

Try a Velocity Deep V or equiv 30 mm rim. Very strong design. I use them on my tandem supporting a 400lb+ tandem team.

Second the Deep V's. They're relatively inexpensive and pretty strong--I rode mine when I weighed 270, including a 12-mile commute of which six miles was on rocky fire roads, with no trouble at all.
Build quality is also important. If he's riding the stock 32-spoke (or fewer) wheels, they were probably machine-built. A good mechanic could true them for a few bucks and that might be enough. But over the years, with my weight varying usually between 220 and 250, I've given up on anything less than 36 spokes.

I like the Mavic A319 myself but there are other options. Here's a link:

http://www.bicyclewheelwarehouse.com/index.php?_a=viewCat&catId=47

Does he break the spokes while braking only? If so, tell him not to use his rear brake.

Keep in mind that every bicycle wheel has 4 components: hub, spokes, rim and build quality. There are probably a lot of combinations of the first three that will work given decent build quality. If the build quality is sloppy, however, you will continue to be doomed to breaking spokes.

Thanks for all the help. I'll pass on the info to him.

my 19yr old mtn bike had the original wheels till last year. the rear sun chinook rim finally buckled. it had all original spokes also. never trued once since i owned it. front rim/tire/tube is sitting on shelf though. has a few minor stress cracks but still all original and straight.

Does he break the spokes while braking only? If so, tell him not to use his rear brake.

Is that a joke?

My cannondale manual says my bike can hold 320 pounds and then some with panniers etc. It has mavic a719 wheels. I weigh 268 and ride rough and no popped spokes.

Is that a joke?
No. He should be using the front brake anyway.

No. He should be using the front brake anyway.

1. It doesn't matter, if he's breaking spokes he should get sturdier wheels. He's not "doing something wrong" like you're implying or saying, and if he used the front brake more he just moves the weight to the front wheel and risks breaking spokes on the front rim anyways. And of the two wheels, if the whole front wheel collapsed it has more catastropic effects than if the whole back wheel did.

2. If you're going to tell people to just brake using their front brake, and say nothing else, you're a dangerous person for anyone who follows your advice. People who aren't skilled at biking risk going headfirst over the bars by not using their rear brake. Is it worth it, in your opinion, to risk breaking a collarbone or possible splitting your head open so they can tell people they were "braking the right way" right before going to the hospital?

People who are used to biking and braking can use the front brake safely because they've learned to brace their body back while braking with just the front brake. If you've learned to do that, THEN you can safely brake using only the front brake. "Only use the front brake" is terrible advice. "Only use the front brake, but be sure to brace yourself when you brake" is at least how it's supposedly supposed to be done.

And I don't even agree with that. I've tried both, and I think putting more braking force on the front brake and a lot less on the back brake, but still some (like 3 on the front brake and 1 on the back brake) is the way to go.

But if you're going to use just the front brake, even a big proponent of front-brake-only, and a well respected source like Sheldon Brown will tell you that's it not as simple as "always use the front brake".
http://www.sheldonbrown.com/brakturn.html

When to Use The Rear Brake


Skilled cyclists use the front brake (http://www.sheldonbrown.com/brakturn.html#frontuse) alone probably 95% of the time, but there are instances when the rear brake is preferred:

Slippery surfaces. On good, dry pavement, it is generally impossible to skid the front wheel by braking. On slippery surfaces, however it is possible to do so. It is nearly impossible to recover from a front wheel skid, so if there is a high risk of skidding, you're better off controlling your speed with the rear brake.
Bumpy surfaces. On rough surfaces, your wheels may actually bounce up into the air. If there is a chance of this, don't use the front brake. If you apply the front brake while the wheel is airborne, it will stop, and coming down on a stopped front wheel is a Very Bad Thing.
Front flat. If you have tire blowout or a sudden flat on the front wheel, you should use the rear brake alone to bring yourself to a safe stop. Braking a wheel that has a deflated tire can cause the tire to come off the rim, and is likely to cause a crash.
Broken cable...or other failure of the front brake.
Long mountain descents, when your front brake hand may get tired, or you may be at risk of overheating a rim and blowing a tire. For this situation, it is best to alternate between the front and rear brake, but not to use them both at once.



Not that this matters. If you're breaking spokes on a wheel on a regular basis, you need to get a better wheel. There's no reason to risk the entire wheel going out while you're riding (ouch).

I was offering a simple short term solution. Rim brakes put a large amount of stress on the spokes during braking. I will agree that I should have mentioned that it's simply a short term solution until he gets a sturdier wheelset.

+1 for the Mavic A-719
http://www.mavic.com/road/products/a-719.324119.2.aspx

I was offering a simple short term solution. Rim brakes put a large amount of stress on the spokes during braking. I will agree that I should have mentioned that it's simply a short term solution until he gets a sturdier wheelset.

What is this relative to? I could be making some incorrect assumptions but it seems to me that rim brakes would be the easiest on the wheel compared to disc or hub brakes. If you apply braking force to the rim and therefore the tire I guess I don't understand how the spokes are really involved. Disc and hub are different since the force is applied to the hub and then eventually the rim/tire through the spokes.

Rim brakes apply a much greater torque on the spokes due to their increased radial distance from the hub.

Edit: This is incorrect. See following posts.

Rim brakes apply a much greater torque on the spokes due to their increased radial distance from the hub.

That's not at all what I've read.

Perhaps someone has a better source, this is the first one I came across -
"Disc brakes require beefier spokes than V-brakes, because the braking force is transmitted through the spokes from hub to rim."
http://www.utahmountainbiking.com/fix/tirelace.htm

I've read other places it's the opposite, to - disc brakes need stronger spokes than rim brakes.

the rim is directly connected, thru the tire to the ground, though , that is where the braking energy goes to stop the bike.

I'd say It's Build quality and Maintainence , the regular checking the wheel for balanced and adequate spoke tension ,
will extend any wheel's service life.

His problem is that the spokes probably are not tensioned properly. The comments here re build quality are probably exactly correct. If you search the forums there are a ton of threads on this issue. If you check the spoke tension on that wheel it probably varies a lot from spoke to spoke and I'll bet none of them are near the maximum tension.

Any bike wheel needs to have the spokes tensioned and stress-relieved properly to be strong. For big riders this is critical because they stress the rear wheel so much. Your friend needs to have the current wheel tensioned/stress relieved and then if he keeps breaking spokes you can discuss a complete re-build or new wheel. A good wheel builder can do this for somewhere between $30 and $60 but do it now before the spokes are damaged any more.

Do it to the front also and you probably won't have to replace that wheel. Even if he gets a new rear wheel the front probably won't need to be replaced unless he feels a need for wheels to match.

That's not at all what I've read.

Perhaps someone has a better source, this is the first one I came across -
"Disc brakes require beefier spokes than V-brakes, because the braking force is transmitted through the spokes from hub to rim."
http://www.utahmountainbiking.com/fix/tirelace.htm

I've read other places it's the opposite, to - disc brakes need stronger spokes than rim brakes.
My bad, this is correct for the reason that fietsbob stated.