Originally Posted by
AdelaaR
The reason why they have disc brakes on mountainbikes is because they ride in the mud ... and with muddy rims the typical rimbrakes will have reduced efficiency because the rims will be muddy.
Discs are located at the center of your wheel and so are less prone to getting full of mud.
For normal riding, however, there is almost no difference between any of the available braking systems because all of those systems brake better than your tire is able to have grip enough not to slip ... which means that your tire will slip on the road way before your brake will slip on the rim.
Exactly. Virtually every bike made today is in a sense over-braked because one can skid the tires without too much effort. Said another way otherwise comparable bikes equipped with disc and rim brakes will stop in the same distance as long as the brakes are dry. In my experience a good set of rim brakes allows as much "feel" or graduated braking effort as a good set of disc brakes. For those of us who ride in wet or muddy conditions disc brakes offer the obvious advantage of the braking surfaces being further away from the road. Beyond that the only remaining advantage is the undeniable attraction of having something new and different. And bike makers as we all know will add something new and different if it sells bikes.