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-   -   102mm Chorus BB 10 speed record crank.. enough clearance?? (https://www.bikeforums.net/showthread.php?t=1175836)

Augie B 06-16-19 02:58 PM

102mm Chorus BB 10 speed record crank.. enough clearance??
 
I am building my old Lemond Buenos Aires into a full Campy Bike, the Lemond has English threads. I have a 10 speed record crank but the bottom bracket That I was using with this crank is Italian (102mm)and will not work with the Lemond. so I ordered a new 102mm Chorus bb w/ English threads. I am a bit worried that the crank won’t have enough spacing from the frame. The Bike originally had an Octalink Shimano 105 crank that was much wider, but I think these cranks used a different taper that allows enough clearance with a smaller spindle... does anyone know if this is true?

alcjphil 06-16-19 03:12 PM


Originally Posted by Augie B (Post 20981705)
I am building my old Lemond Buenos Aires into a full Campy Bike. I have a 10 speed record crank but the bottom bracket for said crank is Italian (102mm) so I ordered a new 102mm Chorus bb w/ English threads. I am a bit worried that the crank won’t have enough spacing from the frame but I think these cranks used a different taper that allows enough clearance with a smaller spindle... does anyone know if this is true?

Confusing information here. Is the frame English threaded or Italian? The spindle length for either for your crank is the same as is the spindle length for most Chorus and Record cranks. Whether your frame is English or Italian the bottom bracket spindle is the same length. The 102mm bb does not change length for English threading

rosefarts 06-16-19 07:18 PM

Italian thread is a different size cup and on one side is threaded different from English. There is nothing you can do to make an English threaded BB fit into a bike that is set up for Italian.

A 102 mm BB is pretty much the standard for 10 speed campy with a double. It fit perfectly fine on my steel bike with a 130mm rear hub.

I currently run that crank on a cross bike with 135mm rear hub. That bike is 1x. I had to get a little funny to get a chain line to work on it.

Also to clarify, Campy ISO and nearly everything else JIS are 2 degree taper. Campy is just ever so slightly smaller. A ISO crank on a JIS bb will stick out 4.5mm further. A JIS crank on a ISO crank will be 4.5 mm further in, and may bottom out if the crank has been reinstalled a bunch of times. It's usually fine to ride if you account for this difference when you buy the new BB.

Augie B 06-17-19 07:38 AM


Originally Posted by alcjphil (Post 20981720)
Confusing information here. Is the frame English threaded or Italian? The spindle length for either for your crank is the same as is the spindle length for most Chorus and Record cranks. Whether your frame is English or Italian the bottom bracket spindle is the same length. The 102mm bb does not change length for English threading

Let me clarify, the bike was originally had an English threaded octalink 105 crank. The bottom bracket I had for this crank was an Italian threaded 102 mm Omni racer bb... sorry for confusion...

Augie B 06-17-19 07:46 AM


Originally Posted by rosefarts (Post 20982029)
Italian thread is a different size cup and on one side is threaded different from English. There is nothing you can do to make an English threaded BB fit into a bike that is set up for Italian.

A 102 mm BB is pretty much the standard for 10 speed campy with a double. It fit perfectly fine on my steel bike with a 130mm rear hub.

I currently run that crank on a cross bike with 135mm rear hub. That bike is 1x. I had to get a little funny to get a chain line to work on it.

Also to clarify, Campy ISO and nearly everything else JIS are 2 degree taper. Campy is just ever so slightly smaller. A ISO crank on a JIS bb will stick out 4.5mm further. A JIS crank on a ISO crank will be 4.5 mm further in, and may bottom out if the crank has been reinstalled a bunch of times. It's usually fine to ride if you account for this difference when you buy the new BB.

I will have to edit my post so it’s more clear. The bike is English, I have a bb for my record crank but it’s Italian, I ordered a new English bb that has the same 102 mm spindle as the Italian bb I have now. I was about 75% sure that these later record and chorus cranks didn’t require as long of a bb as you would usually use.

My bike is also 130mm rear spacing, so hopefully it will work as it did on yours!

rosefarts 06-17-19 08:17 AM

I bet you will be fine.

Augie B 06-17-19 02:15 PM


Originally Posted by rosefarts (Post 20982639)
I bet you will be fine.

I think you’re right, but if I’m not ...I will have a nice bb for sale 😂

CyclingFool95 06-17-19 09:26 PM

You should be fine. Otherwise, I think the next length up is 111 or 115, which was intended for a triple.


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