Bolt sizes?
 

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[Closed] Bolt sizes?

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Trying to source some replacement bolts for bits on my bike. I'm after some help identifying what I need for:

- Shimano SLX shifters (M5x15mm?)
- Shimano XT brakes M785, lever clamp bolt
- Shimano XT M780 Chain ring bolts, triple ring setup
- Caliper brackets (M6x20mm?)
- Caliper to bracket (M6x20mm?)

Any ideas?


 
Posted : 12/06/2013 8:17 am
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Depending on how many you want and how good you are with a hacksaw, for the standard M5 & M6 bolts I'd go to someone like Screwfix and buy a bag of their stainless allen head bolts, then trim to fit.

In fact that's exactly what I did do.

As far as I'm aware any standard chainring bolts will fit your chainset. The last lot I bought (some years ago) were Middleburn alloy ones, red anodized IIRC.


 
Posted : 12/06/2013 8:25 am
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The magpie has bitten though... I'm looking at coloured Ti bolts from http://www.pro-bolt.com/

Tempted to get a selection of 12, 15 20mm bolts and return what I don't use.

The confusion over chain ring bolts comes from them listing 5mm height and 7mm height bolts.


 
Posted : 12/06/2013 8:29 am
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Ah right, you forgot to mention the important bit - you're after pretty colours! 😉

The simplest way of sorting out what size chainring bolts is to remove one you're using now & measure it.

TBH personally I wouldn't bother with ti bolts unless you're a real weight weeny, I'd rather use decent quality stainless for reliability and rust free-ness.


 
Posted : 12/06/2013 8:45 am
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Get aluminium for the first three things - Pro Bolt are good.

XCRacer do good quality reasonably price ti caliper bolts, not coloured, but coloured ti bolts are a bit washed out and rubbish.


 
Posted : 12/06/2013 8:48 am
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Thanks so far.

How do I establish the M size though?

Also, any thoughts on the chainring bolt size?


 
Posted : 12/06/2013 8:58 am
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I've ordered a few M6x20, M6x15, M5x12, M5x15, M5x20.

Will have to find more info on the chainring bolts.


 
Posted : 12/06/2013 9:18 am
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How do I establish the M size though?

Its roughly the outer (major) diameter of the bolt thread. Easiest to measure with vernier calipers if you have some.

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Posted : 12/06/2013 9:22 am