Bicycle Mechanics - Campy Square Taper on Bottom Bracket?

A quick bottom bracket question....

I picked up some old Ofmega cranks (144mm BCD) for my Fixed Gear project bike.

I went to install them on my existing bottom bracket and found that they do not seat as deeply on the square tapered spindle as the previous cranks did.

I am thinking that either my bottom bracket has a Campy Taper, or my new old Ofmega cranks have the Campy spec taper.

Which is it as I want to buy a new Bottom Bracket.

-Matt

Originally posted by SpotmaticF
A quick bottom bracket question....

I picked up some old Ofmega cranks (144mm BCD) for my Fixed Gear project bike.

I went to install them on my existing bottom bracket and found that they do not seat as deeply on the square tapered spindle as the previous cranks did.

I am thinking that either my bottom bracket has a Campy Taper, or my new old Ofmega cranks have the Campy spec taper.

Which is it as I want to buy a new Bottom Bracket.

-Matt Pretty sure the Ofmega has an ISO (campy )taper, and your Spindle is JIS, as the iso taper starts and ends smaller than the jis even tho they both have a 2* taper angle.Therefore the iso does not go onto a jis as far.You also need to get the right spindle length for that crank. If the crank has no great value and the current spindle is about the right length,you really can run the iso/jis mismatch.Many have done so withitout even knowing about it and suffer no consequences.Once done though,you cannot go back the other way.

Are Campy and Shimano square tapers the same? I've always wondered about this but the mechanic at the local bike shop said he doesn't know. He has never worked on anything with Campy parts- not unusual for a shop that is 99% MTB.

Originally posted by cycletourist
Are Campy and Shimano square tapers the same? I've always wondered about this but the mechanic at the local bike shop said he doesn't know. He has never worked on anything with Campy parts- not unusual for a shop that is 99% MTB. Shimano and most oriental stuff is JIS(japaneese industrial standard no less) campy and most european is ISO.

Originally posted by pokey
Shimano and most oriental stuff is JIS(japaneese industrial standard no less) campy and most european is ISO.
Well at least we don't have to deal with Deutsches Institut für Normung (DIN) standards too.

Marty

Thanks for the help folks.

I will prob get a new JIS spec BB and use the original cranks.

I am running only one chainring in the inner position, but would prefer to use the outer position. I assume that purchasing a BB with a shorter spindle would do the trick.

Question:
How is the spindle measured -- end-to-end or some other scheme? I am not sure what size I have now.

Thanks in advance.

-Matt

Originally posted by SpotmaticF
Thanks for the help folks.



Question:
How is the spindle measured -- end-to-end or some other scheme? I am not sure what size I have now.

Thanks in advance.

-Matt End of taper to end of taper.