This has to be the most overrated part in Bicycle History. To me they are a complete waste of weight, money, & upkeep. 'Unless" you like riding in the snow, mud, or similar terrain that effects wheel and rim contact.. AND please do not say wet or raining conditions, linear pull brakes, caliper, and V brakes will stop just as well. Disc brakes tend to squeal just as often, and have there own set of troubles. So what's all the fuss over, that money would have been better spent, on components that really improve your bikes performance. Wheels, tires, drivetrain, saddle, etc.. When I see a road bike with them, I think how cool they look, and then remember what a complete waste they are.