My Cervelo has a Sram Force 22 groupset (BBRight BB / compact crankset / rim brake). I've seen a Red Etap 2x11 speed groupset on Ebay. AFAIK this is the only leccy-shifting groupset that will work with my 11-speed rim brake bike (i.e. wheels, frame, etc). All the newer ones are either/or 12 speed, disc only or 1x11.
The Ebay one comes with a 50-34 Red crankset. Question is - can I use everything else but keep my existing crankset?