I feel like this might be far too broad a question to answer with any certainty but what the hell!

I'm currently running a pair of Roval CL40s on my road bike and wondering what kind of benefit I might see from upgrading to the CL64s. Has anyone seen any reliable data comparing these two (or similar) wheelsets?

I'm mostly riding rolling road races, running Continental GP TTs (23 front, 25 rear); I've read enough ST to know the tyre-rim combo is all important, currently running the 23 up front because a 25 forms a distinct "lightbulb" profile on the narrow(er) CL40s.


Spec: CL40 vs CL64


Rim depth: 40 vs 64 mm
Rim width: 23 vs 29.9 mm
Weight: 1543 vs 1615 mm

Any insight greatly appreciated!