CarGuy

I have a question for the mechanically-minded. I have just acquired a 1989 Pinarello Montello frame which I am in the process of restoring. I have a early 90's Campagnolo Chorus crankset I want to install, however I don't have a bottom bracket. I measured the bike's bottom bracket shell at 68.85mm. My question is what size bottom bracket spindle do I need? Is is a 68mmx111mm or a 70mmx111mm? Or another size? How do I determine the correct size? Thanks for any input.

Bianchigirll 

Is it Italian threading? Assuming it is Italian the 68x111 sounds right. Assuming you do have the low profile 1st generation cranks

VeloBase.com - Component: Campagnolo Chorus

malcala622

Fixed

CarGuy

Yes it is Italian threading. As for 1st gen low profile crank, I don't know. I need to prove I'm not a spammer before I can post a pic.

CarGuy

This is the main reason for my question. Some say 70mm others 68mm. I experimented with fitting Shimano Dura Ace cups, bearings and Dura Ace crankset. The spindles were 68mmx107mm and 70mmx113mm. When I used the 70mm spindle the crank position and chain line was too far away from the frame. In addition, the non-drive side cup stuck out by 2-3mm beyond the lock ring. With the 68mm spindle the crank position and chain line was definitely closer to its ideal position. Also, the 68mm lock ring position was flush with the cup edge. I used the same cups and bearings for the experiment. Bear in mind this was done with all Shimano parts (JIS taper). I don't have the Chorus crank yet as it is currently being shipped.

CarGuy

Bianchigirll Here is the crankset.

Bianchigirll 

I believe that one is either Croce de Anue or a later vintage Chorus, but I don't believe they had the self extractors. The outer ring seems to to be a later vintage.

Personally I never paid too much attention to BB shell width for sizing a BB set. If it was Italian thread I got an Italian thread BB set for the crank I was using

malcala622

Ok first part. Its impossible to use both 68mm (English) and 70mm (Italian) bb cups on the same bottom bracket shell. If its Italian then the BB required is 70mm Italian thread.

Second. Its not really recommended to use a Campagnolo crank with a Shimano bottom bracket. Its possible but better off not mixing those 2 brands.

CarGuy

Just to be clear, I used one set of cups - Italian threaded from Shimano. I used 2 spindles also from Shimano. Don't have the Campy crankset in my possession right now so I used my Shimano Dura Ace crank to test the two spindles. I did not, and will not use a Campagnolo crank on a Shimano spindle.

desconhecido 

Best I can tell, with a Campagnolo square taper spindle, there are at least 4 possibilities for each spindle length. Either the bearing surfaces are spaced for 68mm or 70mm BB shells and for each there is a spindle designed for either thick or thin cups. The difference between the thick and thin cup spindles is 5 mm in the distance between the bearing surfaces 49.5 mm for thick cups and 54.5 mm for thin, for 68mm BB.

So, if you are comparing a spindle for a 68mm BB to one for 70mm BB, the distance on the right side, from bearing surface to spindle end, will be 1mm assuming same spindle length and cup thickness and symmetry.

You seem to have a bike which, if I understand correctly, has a BB shell which is 1.5 mm shorter than it "should" be with Italian threading. With the same fixed cup, the difference in chainline between spindles of the same length, assuming identical symmetry/asymmetry, will be 1mm. The difference in left side crank arm position will be about 2mm. Which selection would match your situation depends on how, exactly, your bike differs from the "normal" Italian BB. Is the 1.5 mm difference symmetric or asymmetric?

CarGuy

Thanks for the accurate description desconhecido ! The BB shell measures 68.85mm which is 1.15mm shorter than 70mm. Your question is a good one because determining the symmetry of the shell hadn't occurred to me. I will get a measurement on that shortly, but for now my guess is that it is symmetric since the bike still has the original paint and I can't imagine a reason why Pinarello would make an asymmetric BB shell. Am I making too much out of the 68.85mm BB shell vs. 70mm spindle difference for setting the appropriate chain line? What I'm looking for is the definitive size for my bike. Many thanks for your input.

Nemosengineer 

Italian Bottom bracket shims are all you need. The wheels manufacturing shims are very good quality, when you setup your chain line place a 1mm shim on the side that is most favorable, that brings you up to 69.85mm

Here is an example: https://www.mtbtools.com/product/bot...ad-components/

: Mike

qcpmsame 

Been trying to find these shims, thanx much for the gouge on a seller.

Bill