HI Ace mechanics
I’m having a head scratcher. I’ve got many bikes and many parts. have built several bikes etc and know my way around. Anyway i was digging around my parts bin the other day and dug up some Chorus Ultra Torque cranks with chainrings n cups attached. Remembering how smooooth these babies were on my geared bike a year or so ago i thought I’d stick them on my SS commuter to replace the rubbish FSA Gossomers I’ve been putting up with. Anyway my issue is converting the double chainring to single chainring. You see with campy cranks you can’t just use short chainring bolts because campy have 1 special bolt that bolts both chainrings to the crank arm itself. Theres a little spacer there also. hmmmmm. Best i can think is to buy a whole set of campy chainring bolts just so i can get the spacer then use the 2 spacers on the crank arm special bolt and normal short chainring botls for the rest. Anyway before I start putting money down i thought I’d ask - Suurely somebody is running a campy UT crank on a fixie/ss???
They are great looking cranks after all :)
I have a pair of UT cranks on my SS. I have the spacer and two brass shims on mine. I also use the outer position because White Industries hubs have a wider chainline.
If you have one set of bolts, I’d get a spacer elsewhere. Anything that’s the width of a 3/32" chainring will do, even a piece cut out of a worn out chainring!
In this setup I was using the inner position for a hubgear, and I lost a chainring bolt due to lack of loctite. Those zipties got me a few hundred kms down the CA coast.
“Anything that’s the width of a 3/32” chainring will do, even a piece cut out of a worn out chainring!"
I’ve done two ghetto jobs before that might help. If you don’t mind ghetto…
Run a smaller chainring on the outside. It’s redundant and won’t be used but fills the gap.
Saw the bolt tabs off a chainring and use them as spacers.
It won’t be pretty, but it works.
If those chorus cranks are 172.5 wanna swap them for some 170 campy strada cranks (i.e single chainring) in reasonable nick?
Potential win-win on offer here…
Think laterally: If it’s a singlespeed and you want to run the chainring on the inside position you could easily shave the teeth of an outer chainring so it acts like a CX style chainguard/bash ring. Looks pretty clean that way and may stop you’re pants from getting caught in the chain.
A dremel, file and some sandpaper are all you need. You can do it with a hacksaw or grinder but I’ve found a dremel with a cutting disc make easy work of cutting the outer teeth and cleaning things up.
I just cut a bit of 10mm tubing or whatever it was down to the 7mm or whatever I needed, and have been running my campy cranks like so for a year and a bit.
@kiwicyclist - sorry bud they are 175mm cranks.
Thanks for all the tips guys. I have some spare chainrings lying around so I may try the “cut off a bolt tab” method and use that as a spacer. Looks like everyone has to ‘backyard mechanic’ this one. Surprised one of the manufacturers hasn’t put out a bolt kit specifically for this but I suppose it’s a niche market.
Wheels manufacturing make a whole set of chainring spacers, it comes in a tacklebox of precision widths and lots of shops have one, check out their site to see what I mean.