Bob Ross

Quoting the Cannondale website:

"Because the Cannondale SI Carbon crankset seamlessly integrates an oversized bottom bracket shell with an oversized spindle and carbon crank arms, you benefit from a direct transferance of power that produces greater velocity while riding, and a crankset that is lighter, stiffer more efficient than Shimano's DuraAce."

I understand that if you want to use any other crankset with this bike (eg., a triple instead of the compact double it ships with, or, I suppose, Campy instead of the stock made-by-FSA) a special Bottom Bracket Adapter is required to (correct me if I'm wrong here) "fill in" the extra space of this oversized bottom bracket shell.

My question: does anyone know if this Bottom Bracket Adapter will compromise the performance of the bike to such an extent that it would mitigate any of the advantages of converting to a triple or a Campy crankset?

I'm buying a new bike this month and the Synapse Carbon 2 is the leading contender. I'm about 90% certain I want a triple crank...but am concerned that by replacing the stock spindle I may be eliminating one of the features that makes the bike so appealing in the first place.

Thanks.

krazyderek

Well you would be, it's called system integration, not system interchangable. I also beleive the BB adapter is a permanent change on the synapse, IE, once installed it can never be removed.

Why don't you just slap on a 34 inner ring instead of the stock 36? and go with a 12-27 that should give you all the range you need. I have the synapse 2 you're looking at and it's great 36-50 is excellent for trainning, hills, tempo, you name it. And i'm running 11-23 on the back. I do find the SI cranks much stiffer then the triple truvali rouleur carbon cranks on my r1000. But i still race on my r1000 cause i like the road feel of the alu caad8 frame when racing, and i just don't use the small ring. 40-52 for racing is perfect too with 12-25.

I do notice a little difference in the BB stiffness of the two bikes, the synapse has a more rock solid feeling when it comes to flex around the BB, especially out of the saddle, but the r1000 is still excellent for stiffness, i just wish they still offered at least one caad8 with the SI BB Now you have to spend the $$ to get a six13, or system six to get the SI BB and cranks.

All this being said, HealthNet, rides cannondale's and they all use DA cranks on their bikes instead of the SI cranks, and they're not exactly known for being the slowest team in North america.

If you're going to spend the money on a synapse try to take advantage of the SI, if not then get a synapse 3 which i beleive already has the adapter in there, or get a bike with a standard BB.

shokhead

I had read there were problems with the SI and when i thought i was getting one i asked if i could get it with an Ultegra and they said no problem that they had to order the bike anyway and would get it with any crank i wanted.

mrt10x

I bought a Synapse frame to build up with parts from my Moto Team SL and installed the BB adapter, well the local Cannondale dealer did. It is a very lightweight aluminum sleeve and the mechanic at the shop said he had heard some talk that it actually made the BB stiffer. I run FSA Carbon Pro Compact cranks and I can tell you there is no flex in that BB.

LazyMike

You won't miss the triple if you get the Synapse with the compact crank, that's what I'm running and like Derek said you can always change to a 34 tooth inner if the 36 is too much. I agree with all he said.