trip221

Stemming from a warranty I am getting a new Cervelo S2 and am still using the original crank that came with my old bike back in 2005 (new BB, but still ISIS). It's an FSA ISIS carbon crank and the BB is a Crank Brothers ISIS.

I'm thinking this could be a good time to upgrade to an outboard BB/crank but was wondering if it would be a noticeable difference? I haven't had any issues with the current set up, other than going through a few BB's, but the Cervelo rep said if he were me he'd consider upgrading to a current BB setup.

Thanks

telebianchi

My '03 Fuji Cross is not at the same level as your Cervelo, but I've gone from ISIS to Shimano external and back to ISIS while switching between CX crank and road compact crank. Can't say I can tell any difference -- they both spin in circles. Unless you have some other reasons to switch cranks, I'd say if it ain't broke, don't fix it.

banerjek

I wouldn't bother unless you have too much cash and need to get rid of some

ericm979

Wait until the ISIS bearings go out, or your FSA cranks get loose on the BB axle.
FSA carbon pros are reasonably light, lighter than many external BB cranks (when you count crank + BB).

Drew Eckhardt 

I'd wait until you wear out your current bottom bracket and then make the swap to an external bottom bracket crankset where the motivation for the change is limited bottom bracket life due to the small bearings on ISIS bottom brackets (the spindle is bigger than square taper, the outside diameter of the bearings is the same, and therefore the individual bearing size must be smaller). That's why external bottom bracket bearings came into being.

trip221

Thanks guys. I was thinking the same thing. A new crankset is a nice chunk of change, but I'll hold off until it's necessary.

oilman_15106

And you like the creak that will develop from the outboard setup.