Spokes keep snapping

[psvrichard]

I have a Ridgeback city bike which cost about £300. I'm 13st and don't go particularly mad and generally ride on sustrans tracks without too many bumps or the road as most of my cycling is commuting. I have snapped a number of spokes but over about 4 years. Each time I get them dutifully repaired only for another to go. I was wondering whether
1) Am I too heavy for the bike?
2) Could my riding style be unsuitable for my type of bike?
3) Is the snapping of spokes just one of those things that happens to us all?

Yesterday I was going down a smooth road and one snapped at about 18mph. In the morning I'd successfully ridden home from Dewsbury which is pretty hilly but it was all on road and I wasn't placing a great strain on the bike.

I don't have much technical know how but the time before this I had to get a new wheel and I thought that had cracked it but yesterday's events put paid to that theory. I'm trying to work out whether I just need to look after my bike better or whether I need a new, more robust machine.

[Si]

I would say probably "no" to 1) and 3), and possible but not likely unless you are really thrashing it to 2).

Assuming that you are running the tyres at reasonable pressures, most likely that either the wheel wasn't well built in the first places, or you have a dodgy batch of spokes. Although the fact that you've managed to snap one on the new wheel makes me wonder - what tyres/pressures are you using, are you also getting a lot of p*nct*res to go with the snapped spokes, do you go around the pot-holes or through them?

[psvrichard]

Interesting reply, thank you. I don't think I've ever had a puncture with this machine which is a small mercy. I try to keep the tyres hard because of the large percentage of on road riding that I do. That said I don't think they are bone hard but prior to yesterday I did pump them up using a footpump which can be used on car tyres so maybe that's it.

It's just annoying because I hadn't been on the bike for a bit and yesterday was my big chance to get back into the swing of things and I blew it. Spent the evening before checking things over and like you I thought that previously I had poor quality wheels only for a spoke to go on a new wheel. It will be at least a week before I can get it fixed and I had hoped to do more riding this week. Never mind, at least I don't think I'm unsuitable to be on a bike! Thanks.

[Si]

Oh, the other things I should have asked are: is it both wheels, only the rear or only the front?
If the rear then are the broken spokes all on one side or on both?

[MLJ]

I have noticed that many factory built wheels are so unevenly tensioned that spokes break. I have only had spoke failures on new wheels but not on hand built ones, providing that the builder knows what he is doing! Try your spokes for sound by tapping with a key or screwdriver: you should get the same musical note off each one in the same direction, left & right, ie 4 notes for the rear wheel and 2 for the front, which is not dished! A flat note denotes a slack spoke and a higher note one which is over-tensioned.

[psvrichard]

The breaks have been on both but only 1 on front with the rest being on the rear, not sure whether they have been left or right, current one is right hand side though but that doesn't tell you about the risk as I can't remember with the others.

[willem jongman]

Spokes should not break on well built wheels. That said, many factory built wheels are not well built. So maybe you have a new wheel, but it is not a good wheel. Next, how many spokes does the wheel have? 36 spokes is really preferable, particulalry on cheap wheels. The other bit of bad news is that once a spoke has broken, the others have also suffered, and are more likely to break themselves. Drive side rear wheel spokes are the most likely to break, and hardest to fix.
What can you do (particularly in future), other than go back to the shop?
Make sure you always have 36 spokes.
Use wider tyres (they cushion the wheel more).
Use 26 inch wheels, as these are stronger for a given spoke count.
Insist on handbuilt wheels.
Get out of the sadle (or just reduce the pressure on the saddle just a bit) when you see a bump.

If you decide to get a new bike, get a good one (a Thorn Sherpa perhaps). That will cost rather more than your current bike, I am afraid, but it will last much longer.
Willem

[Big T]

I find that spokes do seem to have a finite life. I have a hand built rear wheel that's about 6 years old and has been fine up to now, but it has recently started breaking spokes. I think that the spokes have reached the end of their useful life and are starting to fail due to metal fatigue. So time to have the wheel rebuilt, with new rim and spokes, as the rims on its way out as well.

This wheel is a 700c narrow CXP33 on a Camapg Mirage hub with chrome double butted spokes (or they may be stainless). It gets used daily on my commuter bike. I've noticed this phenomenon before, but the length of time from new seems to vary.

[Martin_Edney]

I once had a similar problem, but on the rear wheel a bike which had done a lot of miles. I eventually realised that over the years, the action of me pedalling had gradually worn the spoke holes in the hub to the point where they were oval rather than round (whenever you pedal, your propulsion force is transmitted to the road through the spokes, and so over the years the holes in the hub were gradually worn away). I concluded that this wear to the spoke holes had caused them to become rough edged, and so the newly fitted spokes were failing after a few weeks.

The only solution was a new hub, and sure enough the problem went away after I replaced the hub.

I don't know whether this will apply to you, but if you're breaking newly fitted spokes at the point where they come out of the hub, then this might be the problem.

[willem jongman]

Only if the spokes were not tensioned enough in the first place - common enough in cheap machine built wheels.
Willem

[thirdcrank]

I think you have to accept that when a bike is built to a price, a lot of the less glamorous components will be of a basic quality. Spokes are an obvious example and machine building is not going to prolong their life. An awful lot of these bikes are only ridden a couple of times before they go in the back of the garage so poor spokes and bearings etc., are never exposed for what they are. As Willem points out, once one spoke goes, the rest are likely to be on their way out.

The only long term solution is new, good quality spokes in a hand-built wheel. It's a false economy to use the so-called entry level hubs and rims that came with the bike so realistically you are talking about completely new wheels. That may seem pricey but IMO it's worth it in the long term.

[Len]

I had a succession of broken spokes which I had repaired and the wheel trued (twice) on LBS advice. On 3rd occasion I took it to a different shop who pointed out the blindingly obvious fact that the spokes had been damaged when the chain had jumped off previously. Well, you learn from your mistakes, hopefully.

[songsforpolarbears]

Brilliant thread. Helped me loads with a problem i have.

I have a 2005 Kona Smoke. I break a spoke every 3 months. I think the first one i broke was when on tour so I will have be heavy loaded on the back. That would make sense, right? I estimate I've rode my bike for 100 miles with a broken spoke, all breakages added up.

Try your spokes for sound by tapping with a key or screwdriver: you should get the same musical note off each one in the same direction, left & right, ie 4 notes for the rear wheel and 2 for the front, which is not dished! A flat note denotes a slack spoke and a higher note one which is over-tensioned.

I think I will try this. It will help reduce how regularly the spokes break, right? Although, having read this thread I have deffo concluded I need a new back wheel.

[alicej]

Hiya,

I see you're in Wakey, can you get yourself and the bike to Leeds? If so, would you like to come to the Pedallers Arms http://pedallers-arms.org/who-are-we/ where people could show you how to true your wheels (and probably help you true them there and then)?

The opening times on the website seem to be displaying strangely, but it's basically Mondays and Wednesdays, 4pm - 8pm.

That'd be cheaper than new wheels, and proper mechanics are on hand to check other stuff that might be causing the spoke breakages too and replace anything that might be worn or broken. Plus there's usually tea, often cake, and always friendly people and loads of tools you can make use of.

I'll be there on Wednesday and I need to true my front wheel. Be nice to meet you!

[Gearoidmuar]

Spokes snap because of metal fatigue.
Metal fatigue is greatly lessened if the spokes are evenly tensioned (in the back wheel, on the same side).
It is also, and this is VERY important, greatly lessened if the spokes are stress relieved. To find out about this, use Google. I mostly build my own and am 15st and cycle 7000m/yr. and seldom break spokes.

Also important is the quality of the spokes and the stiffness of the rim. I've come to believe that V-section rims are stiffer and better in this respect.
I don't think I agree with Willem about the tyres. As far as I know the tyre pressure has no effect. It was certainly never mentioned by Jobst Brandt in his great book, The Bicycle Wheel.

Brandt says the spokes do NOT have a finite life if properly fitted. Also if you start breaking spokes, replace them alone and then stress relieve properly and if the spokes are of good quality , etc., no more will break.
I once found that I had 4 broken spokes while touring in Brittany. I replaced the four, walked on the spokes on both sides, to stress relieve, got back on my bike and had no more breakages on that wheel for several years touring. The bike died a year ago but the wheel is hanging in my garage.