Purchased a 2012 cervelo r3 team. That cam with a sram force standard crank 53/39 and want to switch to compact 50/30. 2×10 172.5
Can I swap out the chain rings ? If so which one
Or do I need a new crank ? Is ther a sram force that will work
by titoclemson
3 Comments
You will need new cranks. 53/39 would have used a 130mm Bolt Circle Diameter (BCD) and compact cranks use 110BCD. The 130BCD is larger than a 36T chainring which is why this isn’t possible.
Any compact crankset replacement should work however you’d likely need a new BB as well unless you can still get Apex or non-series Sram or Truvativ GXP cranks in a 10 speed double. (GXP is the bottom bracket interface that your current crankset almost certainly uses.) You could also get a Shimano Tiagra or FSA crank but those would require a new bottom bracket.
Sram has discontinued production for 10 speed doubles in the Red/Force/Rival series as far as I have seen with suppliers so the only way to get a matching one would be second hand.
The 53/39 will use a 130 BCD. The compact 50/34 will use a 110 BCD, so won’t be compatible with your cranks.
Finding a matching crank will be next to impossible unless you find one second hand somewhere. I’d recommend just finding a generic 10/11 speed FSA crank or something instead. Hopefully it’ll be a bit cheaper than a NOS sram crankset too
Pic 3, is that cable digging into the frame?