kommisar

I would like to use a campy chorus 8 speed double crankset on a new build but I dont know some crucial specs.

1) ISO or JIS spindle?

2) length of spindle to achieve a 47.5 mm chainline?

I have searched the interwebs and can't find specs on this 1996 era campy crank. Any one have the necessary data?

Andrew_G

ISO spindle taper. (JIS taper is for Japanese/Taiwanese cranksets.) Otherwise, attach a picture of the crankset, because:


The Record 8 and Chorus 8 crank design was the C-Record style in 1994. In 1995 those cranksets were changed to the 'low profile' design. I recall I'm not absolutely certain) that the 1994 BB axle was 111mm in length, symmetrical, and the new design for 1995 thru about 2003 is 102mm or 103mm, also symmetrical.


You can check the Campagnolo documentation (spare parts catalogs) to confirm the date of your crankset.


https://www.campagnolo.com/US/en/Sup...#documentation

then go to page 3 of the spare parts catalogs, to find 1994 - 1998 catalogs: https://www.campagnolo.com/US/en/Support/download?td=3

Soody

new campag square taper cartridge units are still in production
you can get 102 chorus, 111, or 115.5 centaur

I've had a couple of the 111 centaur ones. Not bad but wore out quicker than i'd like for the price. Chorus is pricer and looks nicer so probably better.
If it's a budget build and a not great condition chainset, you could just jam it on a niceish JIS bb, it'll damage the taper on repeated removals and installs. Sheldon recommends doing it though, i've done it a few times, all good.
I also noticed between different 'iso' and 'jis' bbs the tapers still aren't the same, it's not an exact standard to begin with.

kommisar

Thanks for your information! Looking carefully at the spare part catalogs, I believe I have the "low profile" design because both crank arms have a hollow on the back side running the length of the arms which matches the drawings in the '95 catalog. The cranks of the '94 catalog do not have this hollow. So it sounds like the 102/103mm spindle is the correct length. Is there any documentation where this spindle length would be specified?

Andrew_G

Per this vendor, the Chorus BBs are 102mm:
https://www.modernbike.com/campagnol...ets+Sort101Asc

The vendor also lists the Campy part number, which you can correlate to your crankset via the spare parts catalogs.

dddd

There is no JIS-taper bottom bracket that can give the proper chainline using this crankset.

The shortest-available 103mm JIS bottom bracket will project each crankarm outward 3mm from where it is supposed to be, and the taper engagement will be minimal.

Additionally, any JIS bottom bracket spindle has narrower flats, which isn't be as good as ISO in terms of transmitting torque.

Spaghetti Legs 

That is good info and a general guideline is if the crank has a shield logo, usually a 111 mm axle, if script logo then 102 mm

SurferRosa

And $90 isn't too much if the bike will get ridden. You know exactly what you're going to get, how it will fit, and it will basically last forever.