Wow, they are charging way to much for $150 dollar cranks, if these are the same.
Not even the whole crankset, just the crankarms which I think because of the high cost from SRM is why the OP posted the question. Based on a bit more research via Google, I came across this link of a Quarg Quarq CinQo Saturn
install on SRAM cranks. Based on the images of the drive side crank arms, assuming the orginal poster has a wireless SRM, I am pretty certain that the SRAM and FSA crankarms should work interchangeably with the SRM. If the SRM is wired, then this is not as certain because if you reference the images above, the splines on the crankarm/spindle of the wireless crank in the first image are not the same as the splines of the wired SRM in the second image.
Are you sugesting that the Quarg and Wireless SRM crankarms are inter-change-able?
It would be really nice if it is possible to just change the crankarms for a different system (say SRAM to Shimano).
The SRAM S900 / Bontrager Race X Lite / Truvativ Rouleur Carbon cranks all have the same spider interface. They all have the 3 bolt interface as seen in the first photo above so they are interchangeable with each other. Those three brands are not interchangeable with the FSA Team Issue cranks that the OP has on his bike. The FSA Team Issue and FSA SL-K Light (http://www.quarq.com/
) cranks that we use have the 4 bolt spider interface as seen in the second photo.
The 3rd photo looks like the Cannondale Hollowgram spider interface. It is yet again different than the Specialized spider interface.
In other words, as another poster pointed out, you don't have much leeway for switching between crank manufacturers (SRAM, FSA, Cannondale) with your SRM or Quarq powermeters.
You could, however, send your SRM powermeter and crankset to us and have a Quarq power sensor mounted on the cranks as long as they are a model we support too (FSA, SRAM, Specialized, Cannondale).