Cycling UK Forum

I have changed the chain, rear cassette and pulley wheels on my Campy Veloce Triple (circa 2008) and have now moved on to the chainrings.
It is fixed on with 5 (Hex/Allen) bolts. Four came off fine, but the one located by the crank turns without unscrewing. All the 'sleeve' threads have a slot in them but I didn't need any extra tool to loosen (or retighten) four. Am I missing something? Has the fifth fixing cross threaded?
Very little on the internet to guide me so any advice greatly received.

There's always one of a set that does that!
I usually just give the offending item a spray of something suitable, wait 24 hours if I can be bothered, then making sure I've immobilised the rear, slotted half, they usually separate.

A big screwdriver, even if it does not fill both cutouts, usually does the job of holding the sleeve nut while turning the allen key.

Thanks Simon and Tata, I'll give it a try and report back!

A tire lever can often hold the back enough..

You can buy spanners which are supposed to hold the back-nut of a chainring bolt, https://spacycles.co.uk/ but they are fiddly to use and don't give much leverage. *****dunno why the link doesn't work....search "chainring peg spanner"
If the thing is really tight, or the thread is really stuck, you are going to have to take the chainset off.
I ground up a "tool" on the edge of a cone spanner (no cone spanners were injured in this production)......

IMG_5534 by 531colin, on Flickr

You can see I thinned the spanner a bit so it fits the slot, and ground a "flat" ....with the exception that the "flat" has a peg which fits in the central bore of the fitting. Pop the home made spanner in the vise put the fitting on the spanner, turn the bolt with the Allen key.

There are various special tools for the job. Some are better than others.

So I got it loose by using the end of a screwdriver and successfully removed the big ring. Next step the five nuts on the other side that secure the middle and smallest ring. Four of these came off OK. Last one. Putting a lot of torque on it, the allen key (5mm) slipped and rounded off the hex hole nicely. And I slashed my wrist on the chain ring teeth as the allen key came away...
Chastened (ok, seething) I put a large plaster on, reassembled the big ring, put the chain back on and pushed the bike back into the shed.
Having a beer now.

Here's the Park tool offering on eBay:

https://www.ebay.co.uk/itm/155042668273 ... SwSD9ird4v

I slashed my wrist

Ouch! They sure are pesky critters, them bolts...