Originally Posted by
juan162
Speed really has nothing to do with the size of your wheel. It's largely a matter of fitness and enough gear inches.
People are muddling two issues here.
How fast you can ride on the flats in low windspeed conditions? That depends on your fitness, technique, aerodynamic positioning and bike design.
How fast you can safely ride on a steep downhill before the bike becomes too hard to control? That depends in large part on the stability of the bike at high speeds. This is what the OP wanted feedback on.