1) 40 x 14t is kind of annoying to be in all the time. There's a woman with a custom road frame with a single speed belt drive setup who works on the same campus as me (maybe at Children's Hospital? not sure), and she seemed to have a much shorter gear than I'd expect and just made up with it in cadence. 90 rpm works out to 21.3 mph for 40 x 14t, 19.9 mph for 15t, 18.6 mph for 16t, 17.6 mph for 17t. I should probably go with a 40 x 15t equivalent, or maybe splitting the difference between 15 and 16t if that's possible with the belt. Edit: 40/16 is 2.5, and I could get 2.5 with 55/22, 118 tooth belt, 433 mm chainstay. 2) Also related to this belt drive business is that my current 1x10 drivetrain is driving me nuts. I have a clicking type noise with every crank rotation. Same place in the rotation. Doesn't occur with no chain so not the BB, crank-BB interface, or pedals. As far as I can tell I have simply worn down my Race Face narrow-wide ring. I bought it 11 months ago and have about 1200 miles on the commuter since then per Strava, so perhaps that's its lifespan in these conditions.