Bike Forums

Bike Forums (https://www.bikeforums.net/forum.php)
-   Classic & Vintage (https://www.bikeforums.net/classic-vintage/)
-   -   Bottom bracket question (https://www.bikeforums.net/classic-vintage/1045145-bottom-bracket-question.html)

sloar 01-15-16 09:18 AM

Bottom bracket question
 
I have an Italian frame coming with an Ofmega square taper bottom bracket. Will this work with my Campy Victory cranks?

TimmyT 01-15-16 09:37 AM

Maybe, but you need to know the spindle length and taper. At a minimum we would need to know the model of the ofmega bb.

Compare: VeloBase.com - Component: Campagnolo 403/100, Victory
VeloBase.com - Component: Ofmega Gran Premio

The difference between those two is 9mm, so no, it wouldn't work. The chainline would be wrong.

icepick_trotsky 01-15-16 09:50 AM

Some Ofmega cranks used a proprietary spindle taper that was different than JIS and ISO. Be careful.

Square Taper Bottom Bracket Interchangeability

sloar 01-15-16 09:55 AM

I won't know until the frame arrives. The bottom bracket I have now for the Victory cranks are english thread. I may just put them on the trade thread and get the right one. Thanks.

Salamandrine 01-15-16 09:58 AM


Originally Posted by icepick_trotsky (Post 18461575)
Some Ofmega cranks used a proprietary spindle taper that was different than JIS and ISO. Be careful.

Square Taper Bottom Bracket Interchangeability

While that may be true, back in the day people used to use Ofmega/avocet and campy cranks and bottom brackets together all the time. It may work. Try it.

Obviously the danger is that the campy crank will go down a bit too far on the spindle, affecting your chain line and chainstay clearance. Worse case is that it will bottom out on the spindle before the crank bolt is tight. Easy enough to try.

sloar 01-16-16 04:03 AM

Could I use the Ofmega cups with my Campy spindle?

verktyg 01-16-16 04:24 AM

Chainline, chainline, chainline.... :rolleyes:

Chainline obsession was a peculiar affectation in Britain when they used stiff 1/8" wide chains with 3 speed hubs.

With modern, narrow, flexible chains a 1/4" difference in the position of the chainrings isn't as big of an issue as it once was. Consider modern 10 and 11 speed bikes with short rear triangles...

verktyg :50:

Chas.

jimmuller 01-16-16 06:19 AM


Originally Posted by Salamandrine (Post 18461605)
While that may be true, back in the day people used to use Ofmega/avocet and campy cranks and bottom brackets together all the time. It may work. Try it.

Obviously the danger is that the campy crank will go down a bit too far on the spindle, affecting your chain line and chainstay clearance. Worse case is that it will bottom out on the spindle before the crank bolt is tight. Easy enough to try.

Agreed - try it.

One minor correction though. The crank bolts will always tighten up against something so the fact that they tighten is not an indicator of success. If the spindle sticks out too far through the square hole, not likely, the bolt will tighten against the spindle end but the crank arm will be loose. If the square hole bottoms out against the shoulders of the taper the bolt will get tight but the crank arm will not be seated properly against the taper, and you probably won't be able to tell just wiggling it by hand since the bolt will stabilize the arm. If the hole is smaller than the taper (assuming the angle is the same 4deg for both) then the arm won't go onto the spindle as far as you like, moving the chainline further out and potentially deforming the hole. You can see that problem without having to tighten the bolt fully. If the taper angles aren't the same (check Sutherlands) then it may seem to have tightened but is a bad fit.

And you probably knew all this already.

RobbieTunes 01-16-16 06:44 AM

I'd wait, get it, and see.

I had two Italian frames tham came with Ofmega BB's and Ofmega Mistral cranksets. I honestly can't remember if I ever swapped a Campy crankset onto them, but I think I did put a Chorus crankset on one of them.

verktyg 01-16-16 07:09 AM


Originally Posted by jimmuller (Post 18463626)
Agreed - try it.

One minor correction though. The crank bolts will always tighten up against something so the fact that they tighten is not an indicator of success. If the spindle sticks out too far through the square hole, not likely, the bolt will tighten against the spindle end but the crank arm will be loose. If the square hole bottoms out against the shoulders of the taper the bolt will get tight but the crank arm will not be seated properly against the taper, and you probably won't be able to tell just wiggling it by hand since the bolt will stabilize the arm. If the hole is smaller than the taper (assuming the angle is the same 4deg for both) then the arm won't go onto the spindle as far as you like, moving the chainline further out and potentially deforming the hole. You can see that problem without having to tighten the bolt fully. If the taper angles aren't the same (check Sutherlands) then it may seem to have tightened but is a bad fit.

And you probably knew all this already.

1000 words.... ;)

https://www.flickr.com/photos/282672...57627678462359

verktyg :50:

Chas.

jimmuller 01-16-16 07:20 AM


Originally Posted by verktyg (Post 18463665)

C'mon, that wasn't really 1000 words. Nice pic(s). You win!

JohnDThompson 01-16-16 07:57 AM


Originally Posted by Salamandrine (Post 18461605)
While that may be true, back in the day people used to use Ofmega/avocet and campy cranks and bottom brackets together all the time. It may work. Try it.

Some early production Avocet cranks used the old Ofmega-taper spindles, but most used Campagnolo-compatible spindles.

JohnDThompson 01-16-16 07:59 AM


Originally Posted by sloar (Post 18463538)
Could I use the Ofmega cups with my Campy spindle?

Possibly, as long as the spindle isn't designed for the rifled Nuovo Record cups. If it's a Victory spindle it should work.


All times are GMT -6. The time now is 07:43 AM.


Copyright © 2026 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.