Campag 27.0mm Crown Race?

asprilla

I'm busy building up an early 90s Peugeot Chorus.

As the name suggests it came with a full Campag Chorus groupset. However, I've just tried to put the headset on and the crown race appears to be 27.0mm instead of 26.4mm. I don't think Campag did 27.0mm crown races.

Am I wrong?

I know I can file the crown race to get my 26.4mm to fit, but I'd prefer not to so can I get a 27.0mm crown race and use it with my Chorus headset?
I own a lot of wheels, but I try to rotate them.

supersonic

Crown race as in the ring that fits on top of the fork crown? Are you saying it is a loose fit?

asprilla

supersonic wrote:

Crown race as in the ring that fits on top of the fork crown? Are you saying it is a loose fit?

Nope, other way round. The crown is 27.0mm and the race in the headset is 26.4mm

gfk_velo

27.0 mm ID on the crown race is JIS fit, all Campag headsets are ISO fit, 26.4 mm.

If it's a steel frame you can have the fork crown properly reamed and faced to accept 26.4 BUT .... if the headset is ISO and the frame is made for JIS, you'll have a further problem - the correct ID for a frame fitted with a JIS headset is 29.9mm, the correct ID for ISO is 30.1, so your ISO headset cups will not fit into an unmodified frame.

Any good bike shop should have head tube reamers and facing tools to make this change. Don't try and press the head cups in without doing it - you *may* get them in, with enough force applied - but the long-term effect is often frame failure.

Graeme FK, Velotech Cycling Ltd., Campagnolo Main Service Centre UK | Velotech Cycle Mechanics Training.

asprilla

Cheers for that.

I've tried a JIS and its just far too big so it's definitely an ISO fit. I'm guessing that there is. Either something up with the fork or the race so I'm going to get it into my not-so-LBS and ask them to figure it out.