# Carbon SI crank to Synapse?



## ron_g217 (May 11, 2011)

Newbie question. Just like the title says. Got a Carbon Synapse 5 w/ FSA crank 50/34.
I wonder if this can be swap with Carbon SI crank 53/39 and just change the BB and chain? Does anyone did this before and is it advisable to do? Lookin to save some weight and get bigger crank. TIA for the input.

View attachment 254834


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## CHL (Jun 24, 2005)

It depends if the Synapse has a BB30 bottom bracket shell. If it does, then you're in business. However, it has the regular threaded English 68mm bottom bracket shell then it will never work. 

C.


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## Helitech (Jan 23, 2012)

if you wanna save weight and have some extra cash (who does these days??) go with the hollowgram cranks... saves weight without sacrificing stiffness... either way good luck on the hunt, i had the carbon cranks on my synapse, but as mentioned above my synapse was BB30... I'm a bit heavy, and the carbon cranks felt a bit flimsy on climbs.... just my 2 cents!


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## ron_g217 (May 11, 2011)

CHL:
I think my 11 Synapse has BB30. I will check if that carbon crank has BB30 as well. Seller said it is but won't hurt to double check.

HELI:
Wish I have some extra $$ to grab that hollowgram cranks. I just stumble accross these on CL. Thought it would be a good upgrade to my bike. If I ever go for this hope my 165lbs frame won't feel flimsy on climbs.


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## Helitech (Jan 23, 2012)

Lift up your bike and look at the frame right at the crank... If it says BB30 you're good to go


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## bmach (Apr 13, 2011)

I was just going to say look for the sticker I think all the cf 2011 are bb30


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## Zachariah (Jan 29, 2009)

Get the Hollowgrams. They make the Carbon Si cranks feel like noodles. Every single turn of the Hollowgrams propels the bike like it has a small motor....with pure forward thrust. Start saving...the Hollowgrams completes the Synapse, or CAAD


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## Bob Ross (Apr 18, 2006)

I think I asked this once before but forget if I ever got a response:

Does anyone know whether the current (2012) Hollowgram cranks will fit a 2005 or 2006 Synapse that came stock with the carbon SI cranks? 

This frame has the integrated bottom bracket, no external cups. I think technically this was made before "BB30" became an official standard, but I've heard it suggested that these early Synapse frames conformed to the BB30 dimensions.


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## Dan Gerous (Mar 28, 2005)

Bob Ross said:


> I think I asked this once before but forget if I ever got a response:
> 
> Does anyone know whether the current (2012) Hollowgram cranks will fit a 2005 or 2006 Synapse that came stock with the carbon SI cranks?
> 
> This frame has the integrated bottom bracket, no external cups. I think technically this was made before "BB30" became an official standard, but I've heard it suggested that these early Synapse frames conformed to the BB30 dimensions.


Yes it will fit. The BB30 name was introduced when Cannondale made it an open standard free to use for other companies, but the SI cranksets/BB/frames before that had the same interface, same specs, only the name and availability for other companies changed. So if you have a SI crankset and/or SI specific frame, it is BB30. :thumbsup:


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