[jsilva]

I recently upgraded the crankset on one of my bikes and it uses an octalink BB. I ordered the low-end Shimano ES25 (actually fairly smooth), 73mm shell and I verified the frame and the previous square-taper BB were 73mm. It's installed and works well.

However, I have two observations and wasn't sure if they were normal:

1. If I attempt to screw the non-driveside cup in all the way (it has a lip) the bearing becomes very tight. I've left the cup out a bit, a thread or two showing, but the cup is still tight. How much effect on the smoothness of the bearing is acceptable?

2. The driveside of the spindle protrudes out a little farther than the other side. This causes the chainline to be a bit farther to right than I'd like. Is it normal for the driveside of an octalink BB spindle to be longer than the other side?

Thanks.

 

[SimpleJon]

There were two types of octalink V1 and V2 the spline lengths were different also sounds like the spindle length is not correct on the BB you got. You need to match the BB type and spindle length to the crankset and the desired / specified chainline. No where near as simple as hollowtech II....

 

[jsilva]

Thanks for the reply SimpleJon.

Just to clarify, the spindle length is the same as the previous square-taper BB. It is simply that the driveside of the octalink spindle protrudes out a little more than the non-driveside, and though the overall spindle length is the same the chainline is a little different as compared to the square-taper BB. That part of my question was whether the uneven protrusion was normal.

 

[SimpleJon]

If the carteidge size is the same then I am not sure why the screwing in the caps should interfere with the Bearings - the restriction normally occurs when the cranks are put in and press against the caps.If the spindle length is too short the same can occur when the cranks are installed
As I said the correct spindle length is also dependent on the crankset used so even if the spindle length is matched to the old square taper it may be incorrect as the crankset is different. You can check your crank model number and the correct spindle length on sheldonbrown.com for a 47.5mm or 50mm chainline.