Spokes

[martint235]

Ok I think I've broken the same spoke 3 times now (or the one in that position, you know what I mean!!). 36 hole Shimano 105 hub with a Mavic Open Pro rim on it. I could just be unlucky, I hit a small pot hole today and heard an ominous ping. Sure enough it had gone. They have all gone at the "elbow" but the hole on the hub looks ok.

It's worth pointing out that I fitted the new spoke last time and as those who know me will attest to, this can't be discounted as a reason although in my defence the wheel was running true when I'd finished!!

Any ideas?

 

[e-rider]

are you using decent quality spokes such as DT swiss competition spokes?

 

[Smokin Joe]

Your wheel probably needs re-tensioning.

 

[accountantpete]

36h? - it is either the spoke hole in the rim or you are twisting the spokes when tightening up.

I would mount another spoke and then look to see how it is lying and if there is some spalling that could be getting in the way.

 

[martint235]

are you using decent quality spokes such as DT swiss competition spokes?

I don't know the make. They are the ones my LBS uses if they do the job for me.

36h? - it is either the spoke hole in the rim or you are twisting the spokes when tightening up.

I would mount another spoke and then look to see how it is lying and if there is some spalling that could be getting in the way.

What's spalling?

It all looks ok at the moment. I've been very careful putting the spoke in even to the point of taking the cassette off (spoke is non-drive side and through from the outside of the hub)

 

[accountantpete]

What's spalling?

It's what happens when two metal bits bite into each other - like the little marks you get on freehubs from the sprockets.You get a little indentation and a raised part where the metal has been pushed.

 

[Red Light]

When you fit it are you bending the hub end so that the spoke lies on and is supported by the hub flange and then stress relieving when you have finished tensioning?

 

[martint235]

When you fit it are you bending the hub end so that the spoke lies on and is supported by the hub flange and then stress relieving when you have finished tensioning?

Errm, I've pushed the spoke through the hub so that the round bit is lying flat against the hub, is that what you mean??

 

[Red Light]

Errm, I've pushed the spoke through the hub so that the round bit is lying flat against the hub, is that what you mean??

Read p53 of Roger Musson's guide to wheelbuilding

 

[e-rider]

I don't know the make. They are the ones my LBS uses if they do the job for me.



What's spalling?

It all looks ok at the moment. I've been very careful putting the spoke in even to the point of taking the cassette off (spoke is non-drive side and through from the outside of the hub)

that's a very worrying statement - you should never consider NOT taking the cassette off!!!

 

[martint235]

that's a very worrying statement - you should never consider NOT taking the cassette off!!!

On other spokes threads on here it has stated that non-drive side can be replaced without taking the cassette off. Honest guv!

 

[martint235]

Read p53 of Roger Musson's guide to wheelbuilding

Thanks for that!! Perhaps I should have read that before I replaced the spoke!!! Anyway the spokes seem ok according to what that book says so I'll see how long it lasts this time.

 

[martint235]

The spoke broke again at the weekend. The LBS has re-tensioned the wheel and also put washers on the suspect spoke which he says will help.

Have a feeling I may be buying a new hub soon though!!

 

[PpPete]

The spoke broke again at the weekend. The LBS has re-tensioned the wheel and also put washers on the suspect spoke which he says will help.

Have a feeling I may be buying a new hub soon though!!

I honestly don't know how washers will help - unless your LBS uses really naff spokes which don't have a proper "elbow". What is more likely to help is if the tensions are now reasonably even and high enough.

I've given my Open Pros on 105 hubs (built by me to Roger Musson's "recipe" - when I was still a very inexperienced wheelbuilder) all kinds of abuse and never broken a spoke.

BTW - "spalling" is what happens to stone & brick when water gets in and freezes and cracks off the surface layer.... nothing to do with metal. I believe what accountantpete is thinking of is "galling".

 

[GrumpyGregry]

that's a very worrying statement - you should never consider NOT taking the cassette off!!!

why ever not?

Bending a spoke to fit it is not a crime against humanity. Done it several times on the trail and the spoke has never failed afterwards. They use brute force in the factory to put the elbows on, and the threads, and the mushroom end, spokes aren't made of glass.