25% or so. if i ride my mtb to work, 6 miles, i run out of gears pretty fast. its a 15speed, i think its 30/38/42 and 15/27 in the back. and i spinout on the 42/15 so much. its really anoying. i never feel like i'm in the "right" gear for me. cause of this sometimes i ride my entry level road bike to work. i really hope it doesn't get stolen with 2 ulocks.