[qtip]

I've got both cranks/bb's at my disposal for use on my SS KM. Which would you use?

 

[DiRt DeViL]

I would go Octalink, have heard so many horror stories about ISIS to even consider it.

 

[teamdicky]

Tried them both

I went through XT to Race Face Isis to Race Face X-Type.
I am back to XT Octalink. I only left it the first time thinking I was upgrading.
No bling factor, but it works. In the end that is all I am looking for.

 

[Hollywood]

thanks

I have the same decision in front of me now for road/fixie BB and cranks. Think I'll stick with Chimano.

I went through XT to Race Face Isis to Race Face X-Type.
I am back to XT Octalink. I only left it the first time thinking I was upgrading.
No bling factor, but it works. In the end that is all I am looking for.

 

[Maurice]

I went through XT to Race Face Isis to Race Face X-Type.
I am back to XT Octalink. I only left it the first time thinking I was upgrading.
No bling factor, but it works. In the end that is all I am looking for.

So does that mean that the outboard bearing-style X-Type BB is no good ?

Maurice

 

[teamdicky]

I can't say "no good"

I had mine installed correctly, and I still ended up with a ruined crankarm.
I do think that the Shimano style system seems more sound with the bearing preload being set and then the crank gets tightened.
I am no engineer, nor do I claim to be one. I am just someone who feels a little burned. I'll stick with what I know works. Even if I toast an XT BB it's only $35 down the drain, not $225.

I am sure others have had better luck with X-Type BB's.

 

[Mr.P]

ISIS and Octalink have the same diameter shaft and are limited to the same BB shell size. Octalink chose weight and durability by having 4 sets of bearings - ball and needle. While ISIS took the light weight approach with fewer bearings. Both standards are left with smaller bearings than square tapers.

Check out raceface's service section in their website and they mention chasing and facing the BB face on your frame for maximum BB durabillity. If it is not properly faced it puts angular pressures on the bearing and they fry (with 2 bearing ISIS). Shimano figured "who would do that?" and overbuilt theirs and were correct in the end.

So face the BB shell at your shop (sounds like you have already done this) and get an ISIS BB that has 3 or more sets of bearings or Octalink BB.

A recent post in drivetrain forums liked the RF Signature XS(?).

Also check out FSA. They have just come out with an outboard bearing ISIS BB. yep. ISIS AND outboard bearing.

ISIS can be as reliable as Octalink but it takes some research and effort.

I'm interested know your thoughts in the end, as I'm sure you are one of the few peeps to go outboard bearing and come back to a BB.

Mr. P