i ride 46/16 brakeless. i've got empty threads on the other side of my hub, thinking of getting an 18 tooth cog for my steep climbs on the way home from work. my roommate rides a 44/18 and it drives me crazy when i ride it. you can skid the rear tire if you take off too quickly.... i stop just fine with my gearing. i've had my fair share of close calls, but never because i couldn't stop in time.