Campagnolo Record Bottom Bracket Length

[jim haseltine]

Colnago Master with a Record chainset and matching 102 BB. With the chain on the inner ring (39t) and smallest sprocket (13t) I get an occasional rub on the outer ring pins - nothing else. If it wasn't against 50 years of habit I'd be happy to ride 39/13.

 

[daccordimark]

Just to add, it would be useful to see a picture showing each crank fitted to the 102mm spindle so we can see how far on they go. Also, what's the frame and how long are the chain stays?

 

[LondonClassic]

I would be tempted to try that, but I'm really weirdly sensitive to asymmetry on the bike – I inadventently rode with a bent saddle for a while, and it really messed with me, took ages to straighten myself back out again. I suppose I could counteract it with a 3mm pedal washer on the other side though. If I can't find another solution, I'll go with this.

The 102mm Campag BB is asymetrical by design anyways. Adding one or two 68x1mm spacers on the fixed cup side until you tune the setup correctly is the answer as @Sm@alite has already said.

 

[daccordimark]

The 102mm Campag BB is asymetrical by design anyways. Adding one or two 68x1mm spacers on the fixed cup side until you tune the setup correctly is the answer as @Sm@alite has already said.

Record and Chorus bottom brackets are not asymmetrical.

 

[LondonClassic]

Record and Chorus bottom brackets are not asymmetrical.

Then I am wrong - apologies. Shouldn't trust memory and AI.

 

[jim haseltine]

If it wasn't for the performance of the Shimano cranks I'd suspect the rear triangle of the frame being out of track.

 

[james_from_stoke]

102mm is the correct length for that chainset, I have the Chorus version which is identical apart from the chainring bolts are steel on mine not aluminium. I use genuine Campag bottom brackets and have never had any problems with the chain rubbing on the inside of the big chainring except when accidentally shifting onto the smallest sprocket. That's on various bikes with both English and Italian threaded bottom brackets and varying chain stay lengths.
I have one of those Tifosi / Token bottom brackets that are supposed to be Campag / ISO taper and I can tell just from looking at it that they are in fact nothing of the sort. I tried fitting my cranks onto it and they do not fit correctly. They don't go on far enough which seems to be the opposite problem to the one you have. From your description it seems as if your cranks are going too far onto the spindle so I can understand why you tried a longer one. Are the bottom brackets you're trying symmetrical? They need to be for Record and Chorus cranks. I've just re-read your post and I see you tried a Centaur 111mm which is not symmetrical.
From my testing and crude measurements I think the Tifosi "ISO" taper is somewhere between ISO and JIS but much closer to JIS.

This sounds like a reasonable suggestion - I did think that the cranks appeared to sit quite close to the BB shell, perhaps they're pulling too far onto the axle if the taper isn't the right shape.
I was under the impression all of the newer Campagnolo cartridge BBs were symmetrical - the gap between the cranks and stays appears to be even on both sides, with both the Centaur and the Tifosi. Either way, the chainline is miles off, so it isn't staying.
It sounds like a genuine Campagnolo 102mm bottom bracket might be the right way to go. I'll give it a try.

Thanks for all the helpful suggestions

 

[daccordimark]

This sounds like a reasonable suggestion - I did think that the cranks appeared to sit quite close to the BB shell, perhaps they're pulling too far onto the axle if the taper isn't the right shape.
I was under the impression all of the newer Campagnolo cartridge BBs were symmetrical - the gap between the cranks and stays appears to be even on both sides, with both the Centaur and the Tifosi. Either way, the chainline is miles off, so it isn't staying.
It sounds like a genuine Campagnolo 102mm bottom bracket might be the right way to go. I'll give it a try.

Thanks for all the helpful suggestions

Is your frame British or Italian threaded? I have a couple of spare Campag BBs but can't remember what thread they are.
Are the cranks well used? The tapers could be shot if they've been used with the wrong BB in the past.