Found an interesting article on chain drive verses belt drive efficiency. This test was conducted with respect to single speed bikes but should apply similarly to and FRC drive system. The test was conducted by an engineer who started doing this for himself to proove out the claims of manufacturers of ceramic bearings, lubricants, and such to improve the efficienct of cycling drivetrains for racing.
Interesting…the crossover point was found to be 208 Watts for that particular application. So, it is quite likely that the relative efficiency of the two systems is a moot point for our robots.
I assume the testing was done on new/clean drive systems. Synchronous belts start having an efficiency advantage as chains & sprockets become worn & dirty.
A couple years ago at an off-road bicycle race the Gates-sponsored team was doing okay until it started raining and the course became muddy. Then the Gates team started passing the chain drive bikes & eventually won the race.