For me, 33 mph was easily obtainable on level ground, front or rear hub system (tried both), 240 pounds - bike and rider, MTB with relatively smooth tires, no wind, sitting up. This was a 30 amp controller and 52 volt battery, so 1500w (less however one wants to subtract efficiency). Also about 30 mph was easy with a BBS02 mid-drive, 25 amps, same 52 volt battery, and 48/11 gear. Didn't figure the rpm, but wouldn't be surprised if it was 90 or so.