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How exactly do I know if I have a bent rim? I went to go clean up my bike today and noticed that the back brake (v-brake) was rubbing against the tire and rim of the back wheel. I screwed around with the brake for awhile thinking that it was the problem, but soon realized that when I spun the wheel, it wobbled back and forth slightly. I opened up the quick release and took the wheel out, held it by the axle, and spun it. It still seemed to look distorted a little bit (looked a little like there was a bulge at one point of the wheel) but enough so that it would severely impact riding...

Any ideas of what the problem may be? Is it possible its a loose spoke? If likely, how exactly do I check each spoke correctly? If it seems to be a bent rim, how do I go about fixing it? Costs?

It should probably be noted that the last time I rode the bike before noticing any problem I was doing a few small drops ( 2-3 feet). I was either landing on the back wheel first, or on both wheels at the same time. Its a hardtail specialized stumpjumper with Mavic 221 rims. Here's a link for all the specs on the bike: link

Thanks for your help!
 

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dipstik said:
How exactly do I know if I have a bent rim? I went to go clean up my bike today and noticed that the back brake (v-brake) was rubbing against the tire and rim of the back wheel. I screwed around with the brake for awhile thinking that it was the problem, but soon realized that when I spun the wheel, it wobbled back and forth slightly. I opened up the quick release and took the wheel out, held it by the axle, and spun it. It still seemed to look distorted a little bit (looked a little like there was a bulge at one point of the wheel) but enough so that it would severely impact riding...

Any ideas of what the problem may be? Is it possible its a loose spoke? If likely, how exactly do I check each spoke correctly? If it seems to be a bent rim, how do I go about fixing it? Costs?

It should probably be noted that the last time I rode the bike before noticing any problem I was doing a few small drops ( 2-3 feet). I was either landing on the back wheel first, or on both wheels at the same time. Its a hardtail specialized stumpjumper with Mavic 221 rims. Here?s a link for all the specs on the bike: link

Thanks for your help!
Sounds like your wheel has come out of true (non technical term is it is bent or something.....) Best bet is to take it to your local bike shop where you purchased it from and they will fix it for you. Most bike shops will do this for free if you had purchased the bike from them and it is within its first year of use. Most I have been charged is like $10 for a minor re-truing.
 

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bent rim vs. out of true...

Run your finger along the rim where its "bent"

If you can feel a depression, or dent, then the rim is damaged. Sometimes, its possible to bend it straight using a crescent wrench, but only for very minor stuff. Otherwise, the rim should be replaced.

If its out of true, that means the spoke tension is out of whack. Pluck the spokes with your finger -- they should roughly make the same tone.

If some are noticeably higher/lower in tone, those are either too tight or loose, respectively. If some are too loose, try squeezing those loose spokes -- chances are they'll be laced on the opposite side of the bend to the hub. If the rim straightens out, tighten those spokes 1/2 turn at a time (using a spoke wrench!) Remember, it's opposite of "righty-tighty"

Dont overdo it, or you'll be in real trouble
 

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Most bike shops will do this for free if you had purchased the bike from them and it is within its first year of use
Most shops will true a wheel if it has come out of true under normal circumstances. Hard off-road riding, jumping, or dropping 2 to 3 feet is not normal. Yes, a shop might true the wheel for free but do not be shocked if they charge you because the wheel has been abused.

If you are going to play hard you will have to get used to the fact that you have to pay sometimes.

If you continue to knock you wheel out of true I would suggest looking into a "down hill" type of rim and having your wheel rebuilt.

My two cents worth.

Tad
 

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Scanner said:
Most shops will true a wheel if it has come out of true under normal circumstances. Hard off-road riding, jumping, or dropping 2 to 3 feet is not normal. Yes, a shop might true the wheel for free but do not be shocked if they charge you because the wheel has been abused.

If you are going to play hard you will have to get used to the fact that you have to pay sometimes.

If you continue to knock you wheel out of true I would suggest looking into a "down hill" type of rim and having your wheel rebuilt.

My two cents worth.

Tad
How are 2-3ft drops not normal?? Dont you come across those even on some xc trails??
 

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If you read your new bicycle warranty closely the warranty is void if the bicycle is used for jumping, racing, stunts and many other things. This is a CYA for manufacturers. In the road bike world many high end custom bike have almost no warranty on them. Why? Because th maker knows that they are going to be raced. And stuff happens when you race.

I don't know where you ride but the XC trail where I ride you have to go looking for three foot drops. I am sorry but if you walked into my shop and said that you were dropping from that height I would not warranty your rim if it needed to be replaced. I would true it for your to BAP (best as possible), but you have to realize that most rims are not made for such abuse. Yes they are strong but not that strong. A three foot drop at speed with a grown adult on the bike you better hope you land centered. I don't know what the physics are behind that but the force that would be applied to a wheel has to be huge.

If you are, on occassion, dropping that height your wheels should hold up fairly well. But if you are spending all of your time looking for those drops and riding them time after time then be prepard to pay.

Also, what air pressure are you running and how much do you weigh? On trails like you are riding I would be suggesting a "high" pressure depending on your weight. A fully inflated tire will do a heck of a lot to protect a rim from being beat up.

Real life is different from what manufacturers acknowledge. They know that you are doing stuff like that but they don't want you to go back to you LBS and say "I was just riding along when..." Horse Hockey! And the shops know it. Tell the truth and it will get you a lot further with the shop.

Ride Hard! But don't put it away wet!

Tad
 
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