Are chain ring bolts a common size?

Are chain ring bolts a common size?

Author
Discussion

Steve vRS

Original Poster:

4,836 posts

240 months

Monday 27th June 2016
quotequote all
I need to replace a chain ring and a bolt after this.



I've managed to order a chain ring but am struggling for the bolts. Are double chain ring bolts a standard size? It's an FSA Omega crank but the rest of the drivetrain is Shimano 105.

yellowjack

17,065 posts

165 months

Monday 27th June 2016
quotequote all
I think they vary, between manufacturers and even groupsets.

I lost one from a 6700 Ultegra chainset (which fortunately didn't fold up like yours) but the first replacement bolt from a decent local bike shop was completely the wrong size. Although the next solution fitted OK, it wasn't a perfect match for the fitted bolts, so I'd assume there are a number of 'standard' sizes available but no "standardised" solution common to all component manufacturers/groupsets.


Having thought about it, though, the higher-end Shimano chainsets have bolts only on the rear, fitting into threaded holes on the rear of the outer chainring. Yours are two-part 'bolts' by the looks of things, so might be a more 'standardised' part. Hopefully.

Mad March Taffy

508 posts

118 months

Monday 27th June 2016
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Try looking at the Race Face chainring bolts in Chain Reaction Cycles

They look like they would do the job for you

anonymous-user

53 months

Monday 27th June 2016
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Steve vRS

Original Poster:

4,836 posts

240 months

Monday 27th June 2016
quotequote all
CoinSl0t said:
Yes, thanks. Appears that there are standard dimensions. I'll 'borrow' one of my other bike and then order a set from the usual place.

Cheers!

upsidedownmark

2,120 posts

134 months

Monday 27th June 2016
quotequote all
Basically they're standard unless you've got something funky, which you haven't. Shimano tend to use stainless ones with an odd (torx?) head, which are a good choice for strength and longevity, but (infinitessimally) heavier. Most are just alloy hex heads.

Moaningroadie

264 posts

191 months

Monday 27th June 2016
quotequote all
Got to ask - how the hell did you mange to do that?!

anonymous-user

53 months

Monday 27th June 2016
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At a guess, one ring worked loose and fell out, the next time he put pressure on the pedal it twisted the ring.

Steve, you just need a double chain ring bolt, I've never known there to be a difference between them. The outer part, the important bit, has always been a standard length

Edited by anonymous-user on Monday 27th June 22:41

Steve vRS

Original Poster:

4,836 posts

240 months

Tuesday 28th June 2016
quotequote all
Moaningroadie said:
Got to ask - how the hell did you mange to do that?!
Power- Bazooka!!

No,Pablo was right. The bolt went missing after the Grizedale Grizzly CX ride a few weeks ago and I never quite got round to replacing it. Then riding home from work last week, I accelerated out of a junction and whoops!

All sorted now though thanks. I borrowed a bolt off my old road bike and it fits so now I can buy a new set off Wiggle. It was something neither Halfords or 2 LBSs sold!

Steve