Breaking Spokes

[vinski]

Hi All

Currently riding a 3 year old Giant FBR and in the past 5 days i have broken 2 spokes on the rear wheel. After getting the first fixed over the weekend, i spoke to the LBS about what could be causing it and whether or not i should get a new, stronger wheel as im fairly heavy (105kg, 110kg with my backpack). They pretty much advised that a cheaper route would be to replace all my spokes with some stronger ones. But they said to keep riding first as they didnt think i would break another spoke for awhile. Anyways, should i get the spokes replaced or just get a new wheel? Any suggestions for a rear wheel around the $200 mark?

Cheers
Vinski

[goneriding]

Sounds like the LBS is giving you good advice which is to be cherished!

What I've found is that you seem to get clusters of spoke breaks. In the past I've taken the approach of getting a re-spoke after a couple of cluster breaks. No reason other than it seemed like the logical thing to do.

If you are considering a new wheel (do I detect a whiff of upgraditis?), at your weight, I'd be looking at something with a high spoke count and, depending on how much and what type of riding you are doing, will determine the quality/price point.

For example, if it is a commuter wheel you want, weight and rolling resistance are of lower importance than durability.

[zero]

Its the usual way of dealing with it - if spoke failures won't go away, get it fully respoked, after assessing the remaining life in the braking surface on the rim etc.

I have a wheel that is getting on towards 7 years old, it was fully respoked at 4 after a failure and was reliable since. It has worn out 2 freehubs and broke an axle when it was 5 years old (bearing in mind that its a mountain bike that both commutes and races so has a hard and at times muddy life), so one advantage of replacing wheels eventually is you renew those sort of components too - load on an axle from a 110kg rider is not insignificant.

[vinski]

At the moment all i do is commute on it, roughly 12kms each way and 99% of the time its on the road so my preference would be for a strong wheel as speed/weight savings are not my priority.

Looks like ill be heading back to the LBS to get the wheel respoked with some stronger spokes.

Thanks
Vinski

[human909]

Good advice by LBS. Good advice by forums.

WIN!

[vinski]

Just called the LBS and spoke to the same mechanic, he advised to get a new wheel as i broke another spoke that quickly. So im taking it in after work and having a look at the new wheel which they said will cost $105 plus a small labour charge. Looking at their website, they have a few DT Swiss wheels on sale so im thinking its probably one of these - are they any good? Sorry i cant be more specific.

Cheers
Vinski

[simonn]

Need details.

[jules21]

i have previously and am experiencing the same phenomenon. what can happen is that as you break spokes, the stress on other spokes is increased. as you replace them and retension them, the stress is also increased. even releasing tension on spokes can cause breakage - one of mine broke when i loosened it the other day - i'm unsure whether this was caused by reducing the tension in it, or that the twisting action (caused by the spoke binding in and turning with the nipple when applying the spoke wrench) increased the tension.

bottom line is - once you upset the "stress equilibrium" that the spokes have existed under, i.e. by breaking one spoke, others will often start to break.

[zero]

i have previously and am experiencing the same phenomenon. what can happen is that as you break spokes, the stress on other spokes is increased. as you replace them and retension them, the stress is also increased. even releasing tension on spokes can cause breakage - one of mine broke when i loosened it the other day - i'm unsure whether this was caused by reducing the tension in it, or that the twisting action (caused by the spoke binding in and turning with the nipple when applying the spoke wrench) increased the tension.

bottom line is - once you upset the "stress equilibrium" that the spokes have existed under, i.e. by breaking one spoke, others will often start to break.

They break because they have been too close to yield whilst being load cycled (by turning with weight on them) for some time and are stress cracked (fatigued). ie you can safely buy 72 spokes and assemble 2 wheels, because they won't be stress cracked when new and they won't break, even if you do them up, and undo them many times. You don't need to buy 73 in case one breaks!

There isn't really an equibrium as such, a fresh spoke is MUCH stronger than is actually required and is rather ductile, won't break even if thoroughly overloaded - it will deform.

Hand build wheels often last many times longer than cheap machine built wheels because they are deliberately overloaded by the builder squeezing the spokes together- which forces it to yield (higher load than riding) in the directions that riding loads occur, which happens to relieve the internal stresses on the spoke, at least as far as riding direction loads are concerned.

[jasonc]

pro-lite como /thread

i broke 2 spokes on my flat bar in a short period. bought a pair of the como's. couldn't be happier.

[vinski]

Thanks for all the replies. Ended up getting a new rear wheel, not too sure of the brand now but they assured me that it would handle my weight and i wouldnt get anymore spokes breaking. He actually said that the rim would probably break before the spokes!

I had a read about the pro lite como and they look pretty good, but i didnt want to wait around for a set to be delivered as ill be getting the bike back later this afternoon. Maybe ill get them for my next bike or when i get upgraditis!

Cheers
Vinski

[jacks1071]

Thanks for all the replies. Ended up getting a new rear wheel, not too sure of the brand now but they assured me that it would handle my weight and i wouldnt get anymore spokes breaking. He actually said that the rim would probably break before the spokes!

I had a read about the pro lite como and they look pretty good, but i didnt want to wait around for a set to be delivered as ill be getting the bike back later this afternoon. Maybe ill get them for my next bike or when i get upgraditis!

Cheers
Vinski

You could have them on hand as a spare set