Chainring bolts - all the same size?

[Sergeant Pluck]

Hi all

Just finished off a bit of fettling there by tightening my chainring bolts. I sheared one off  and sliced open my finger.

Are all chainring bolts the same?

In other words will one off my Marin (105 triple) fit this Ultegra compact? I'll sort it out properly next week but for now I just want to get my bike fettled and boxed for a trip away on Friday. 

(Off topic: I just cannot find a decent comfortable chain ring tool).

[Biggsy]

Most chainring bolts are interchangeable, so you'll probably be able to use one you have already.

No need for a back spanner for the nuts.  Just keep spinning until the nut stops slipping - which will happen once the grease or dirt on the outside has dispersed.

[Sergeant Pluck]

Thanks Biggsy 

I think most of mine do stop turning without a back spanner, but one or two just never seem to "grip". Maybe the new one will...

[Sergeant Pluck]

Swapped over fine. Both OE Shimano bolts but are very slightly different in the "nut" section.

Isn't it strange how some of them just grip and some don't, despite application of a smear of assembly grease to all parts.

[Adrian]

Swapped over fine. Both OE Shimano bolts but are very slightly different in the "nut" section.

Isn't it strange how some of them just grip and some don't, despite application of a smear of assembly grease to all parts.

I've never got beyond annoying

[Sergeant Pluck]

 

Annoying was above, when I sliced open my finger. Beyond that lies strange.

[ABlipInContinuity]

Along the same lines, the tandem has shed three of it's five chainring bolts from the front timing chainring.

As these bolts are for a single ring, are they shorter than normal?

Can I temporarily, steel the chainring bolts from my fixie? (..again single chainring)

Thanks

[giropaul]

Without a tool for the back of the bolts it is difficult to get proper tightness (although by luck it can happen). This can be the cause of the annoying tick or creak that haunts most cyclists.

VAR (I think) make a tool that looks a bit like a G-clamp, with an allen key on one side and the tool for the slot on the other. (not helpful with Campag Record now that uses Torx).

I have in the past made a usable tool from an old large screwdriver  by filing out the centre of the blade.

[ABlipInContinuity]

Will these fit?

Found a tool to help. But surely the back of a normal knife (as in cutlery) would do wouldn't it?

[Biggsy]

A knife or any tool that doesn't fit extremely well indeed on the nut won't be any use at all once the bolt is nearly tight - and even some tools intended for the job don't fit well.  You can just use your finger to get it started.

I have never needed a tool on the back of any chainset to get proper tightness.  The nut will eventually stop slipping if it does slip.  That happens as grease on the nut interface with the chainring disperses or burns off.  Then it is possible to over-tighten the bolt, let alone properly tighten it.

Remember to grease or anti-seize the bolt threads (but try to keep the nut exteriors dry).  This enables greater tightness as well as preventing seizure.

[ABlipInContinuity]

I'm going to pop it into the (studenty) LBS at lunch time. I've given them a call and they are only charging £4 for a set of bolts instead of a fiver, which is the best online price I can find.

It's my poor fettling that is to blame in the first place. I was having issues with uneven tension on the timing chain, so I slackened the chainring bolts and then retightened them. Two of the bolts in the front chain ring wouldn't stop turning.

I tend to use copper slip when reassembling anything I have dismantled.

Thanks Biggsy.

[harrumph]

VAR (I think) make a tool that looks a bit like a G-clamp...

It's the VAR 352, and is spring-loaded. But getting hold of one seems to be impossible.

Chainring bolts have long been one of the few bicycle bits that just don't work very well. However, there is a solution at last - 6mm Allen key one side, Torx key the other  

[ABlipInContinuity]

Thanks H.

Looks like I has been a muppet.

The remaining two bolts in the front chainring were loose. All the bolts in the rear chain ring were perfectly well tightened up.

It would appear, that I forgot to tighten up the front chainring bolts. At all.