Need two new steerer clamp stem bolts for my Thomson stem. They’re 24mm long and 4mm diameter thread with sweet tapered allen key heads.

Where can I get some?

CRC used to sell spares.

i have a bag of 6 if you want them for postage? email in profile

rob jackson, are they silver? are they the same as the ones i need to replace?

Stem is an Elite X4 and the bolts look like this.

P1060610.JPG by cakefest, on Flickr

They look like ti ones – certainly not the standard bolts.

Pro-Bolt are excellent for replacements if you want to continue with something a bit fancy!

I got some off ebay cheap as chips.

http://www.ebay.co.uk/sch/i.html?_odkw=allen+key+bolts&_osacat=0&_from=R40&_trksid=p2045573.m570.l1313.TR0.TRC0.Xblack+allen+key+bolts&_nkw=black+allen+key+bolts&_sacat=0

not sure what ‘M’ size these are. how do i work that out?

I’m trying to remember what I ordered! Need to check when I get home. Think they were M5? Is not stamped into the top of the bolt head?

no, nothing stamped into these bolts.

http://www.pro-bolt.com/stainless-steel/stainless-steel-bolts-tapered-socket-cap.html

Okay, I’ll check when I get home.

not sure what ‘M’ size these are. how do i work that out?

‘M’ size = thread diameter.

That said, I thought Thomson stems were M5s, but you’ve measured them as 4mm.

M5

yeah, on 2nd measure they look more like 5mm.

does the length measurement run from the base of the tapered head to the end of the bolt? 20mm in this case.

Indeed it does, so you need some M5x20mm bolts in your chosen material, avoid aluminium!

And plastic.