I think I get about 10 mph according to my speedo with it set rite with it set wrong I get 25 on my hardest rides and a few down hills I get 30 or 32 that's with it set wrong set rite I get 15 to 20 I wonder if every bodies speedo is set rite don't sound like they are and if you do manage to get 25 to 30 on flats you are pushing your self really hard.