How do you Measure an Isis Bottom Bracket Axle?

[MikeWarner]

Hi. I have just removed an FSA Platinum Isis BB to measure the size. The shell size is printed on the sticker on the casing and is 68mm. The axle length is not marked anywhere. I have measured it as 128mm. The problem with this length is that it is longer than expected and that the widest this BB comes in (with a 68mm shell) is 118mm.

Is there some different way to measure these Isis BBs?

 

[FluffyChicken]

FSA ISIS Platinum sizes
73mm e-type comes in the length (FSA website)

From what I've read of ISIS MTB triple would be 113mm length.



That helps you didly squat though

 

[Splatter Paint]

Hmm, that's a bit odd, I'd thought it would be the total axle lenght....

What is the distance between the start of the splines? If the splines are 5-6mm long and you subtract that from the total lenght do you get a sensible number?

 

[MikeWarner]

It is Isis, so the splines are like 20mm long, so it can't be that. It probably is the 128mm I measured, but strange that FSA don't list this size. Maybe it is a discontinued size?

The reason I'm asking is that it is from my trials bike and the cranks are knocking the Maguras under pedalling load. I've managed to adjust them so they don't, but brake feel is wrong. I may have to wear down my pads with a milling machine to create more clearance (3mm each side should do it).

Oh well.

 

[Splatter Paint]

Ah I see, I was thinking about Octalink......I forgot ISIS had much longer splines.

 

[Xesh]

It sounds like you've got an FSA Platinum Pro DH BB. They don't always have the "pro" on the BB though.

CRC have some of that exact size in stock.

http://www.chainreactioncycles.com/Mode ... delID=5593