My stock geared summit highmark 151 (700),geared at 19\43 would top out about 85 to 90mph on a groomed road. If you don't go faster than that then might as well gear down. More pros than cons unless all you do is high speed. FWIW my current gears are 17\47 and i can still hit about 78mph, i only ride mountains so top end is of no consideration to me. With lower gears and proper clutching it will launch from a stop quicker.
