Cycling UK Forum

Had a front 700c touring wheel built in about 2013, Shimano dynamo hub and spam (edit: haha, I meant sapim!) double butted spokes.
Used the bike for two shirt rides, C2C over 3 days and a local ride. All was well. The bike spent the next years mostly in the shed, and on taking it out broke 2 spokes just riding down the road (one had possibly already broken in the shed I'm not sure).
LBS fixed and trued it, and said all was well. (the dynamo hub needed new internals but that's another story).
I did a ride down to Isle Wight, and on the way I broke two more spokes. One on the way down, had it fixed in a bike shop, and then another around the IoW.

The stock rear wheel has never had any issue and carries the weight of panniers and tent. The expensive hand built wheel seems to be completely unreliable to the point I'm not sure I trust the bike but don't really want to spend on a complete rebuild. There's no front panniers on the bike. On the recent ride, both the front spokes went on 25-30mph downhill runs.

Any ideas what's happening?

It's not really surprising given that you have spam spokes. It doesn't have a very high tensile strength and if left in storage may get nibbled. I'm sorry I have nothing useful to contribute

Seriously though it sounds like the wheel is built or specced/laced wrongly/unsuitably. Either that or it got damaged/stressed somehow in storage.

It's not going to get any better, and leaving it as is is not an option. Strip, sell the parts and buy a new handbuilt Dyno wheel from Spa or suchlike, unless it's a particularly nice hub eg LX/XT or Son etc in which case a rebuild using new spokes/rim might be in order, obviously by someone who knows what they're doing.

Sapim have occasionally produced batches of bad spokes which behave exactly as you describe (*). I didn't believe this until I saw it with my own eyes. Are the breaks randomly at mid-length? If so they are almost certainly bad spokes and you should definitely get the wheel built with new spokes.

However if the breaks are all at the J-bend then it is more likely to be a bad wheel build. Same solution (new spokes) would be best, but there is a chance that you could stress-relieve the wheel and see if that improves matters.

(*) stainless steels of the sort they use can easily become embrittled if some moron heat-treats the material at the wrong temperature. I suspect that this is reason for the problem spokes, but have no evidence to back this up.

cheers

If the rim is good and since you have already spent money on the hub refurbishment with new internals then a new set of spokes (£10-20 + labour) should leave you with a wheel that will give many years of service. I do not see the logic in Gregory's argument for ditching the good parts as you will probably not get very much money back for them.

It is not to hard to lace and true a wheel if you have a few hours you can spend on it, there is lots of good advice on how to do that here which helped me to build my first wheel last year.

Thats the French for you, saved all the iffy spam fur us Brits. They think we are heathens who cant tell the difference, well we can. I like it battered and deep fried.

Wouldn't be hard to lace in new spokes.

Any reason why you couldn't do a spoke at a time??

For me measuring the correct spoke lengths was the hardest part!!!

Cheers James

Jamesh wrote:Wouldn't be hard to lace in new spokes.

Any reason why you couldn't do a spoke at a time??

For me measuring the correct spoke lengths was the hardest part!!!

Cheers James

with all the crossing think it might be very difficult to do one at a time, maybe it is possible to do one side at a time and follow the pattern?

alexnharvey wrote:with all the crossing think it might be very difficult to do one at a time, maybe it is possible to do one side at a time and follow the pattern?

If you do them 4 spokes at a time, 2 from each side of the wheel, you can cross and lace without having to bend spokes.

fausto99 wrote:

alexnharvey wrote:with all the crossing think it might be very difficult to do one at a time, maybe it is possible to do one side at a time and follow the pattern?

If you do them 4 spokes at a time, 2 from each side of the wheel, you can cross and lace without having to bend spokes.

That sounds like a good plan and would make it quite easy to copy the pattern from the neighbouring pairs.

Brucey wrote:Sapim have occasionally produced batches of bad spokes which behave exactly as you describe (*). I didn't believe this until I saw it with my own eyes. Are the breaks randomly at mid-length? If so they are almost certainly bad spokes and you should definitely get the wheel built with new spokes.

However if the breaks are all at the J-bend then it is more likely to be a bad wheel build. Same solution (new spokes) would be best, but there is a chance that you could stress-relieve the wheel and see if that improves matters.

(*) stainless steels of the sort they use can easily become embrittled if some moron heat-treats the material at the wrong temperature. I suspect that this is reason for the problem spokes, but have no evidence to back this up.

cheers

Do you know if Sapim offered replacement spokes to those affected or if they ever acknowledged the issue publicly or privately.

alexnharvey wrote:Do you know if Sapim offered replacement spokes to those affected or if they ever acknowledged the issue publicly or privately.

I've seen no such acknowledgement and when I sent such duff spokes back to Sapim (Belgium) myself I didn't hear back from them; zip, nada, nothing.

cheers

must be pretty bad for a front wheel to go?

Brucey wrote:Sapim have occasionally produced batches of bad spokes which behave exactly as you describe (*). I didn't believe this until I saw it with my own eyes. Are the breaks randomly at mid-length? If so they are almost certainly bad spokes and you should definitely get the wheel built with new spokes.

However if the breaks are all at the J-bend then it is more likely to be a bad wheel build. Same solution (new spokes) would be best, but there is a chance that you could stress-relieve the wheel and see if that improves matters.

(*) stainless steels of the sort they use can easily become embrittled if some moron heat-treats the material at the wrong temperature. I suspect that this is reason for the problem spokes, but have no evidence to back this up.

cheers

Thanks for all the feedback. Yes, so far all 4 have broken pretty much in the middle, leaving me to tape the two dangly bits to keep riding. My initial thought was bad spokes as it was discussed with the builders (Spa) at the time and all specced for the job. Exal rim, Shimano XT dynamo hub, and new spokes.

I guess in that case I should just get it rebuilt, maybe a new rim also as it was quite out of true after the first two went, maybe the tensions all wrong now? I'm pretty good with bike maintenance in general but a bit of a novice with wheels.

To be honest, my tourer is heavy (and I'm ten years older since I toured previously) so I've actually ordered bike packing bags and MTB wide range cassette for my carbon road-bike to try a bit of lighter touring, maybe in B&B's rater than camping. If that works out I'll probably get a gravel bike. But meanwhile a bike with a broken wheel's a bit pointless, I'll see if I have the original stock wheel maybe as a stopgap, but I do like the dynamo for lights and GPS charging!

I've used Sapim Race from time to time but I always buy DT if I can get them in the right length. I find them more consistent and easier to build with. Never broken one.

The only spoke that ever broke on a wheel I built was a no-name spoke from a Fuji Track that I'd ridden for a bit, laced to a new hub, then ridden for another 16 years. Luckily, it finished last year's Dunwich Dynamo and only broke a month or so later.

I’ve only ever broken 4 spokes in all my cycling. All on this one wheel!