what's the difference between this two type of mounain bike?

Question

there are some mountain bike with a front suspension that is covered by a piece of black rubber. and there are another type with front suspension but without any black rubber covering the suspension. what's the difference between them? which one is better?

Answer 1

The rubber boot is a dust cover. Although you might find a boot that covers a couple of inches of stanchion, or one that just sits on top of the seal, the function is the same - keep water and dust from getting into the fork.

As for best - neither, since both types achieve the same result. However, there are a great many forks out there. You might want to research which will give you the best damping, adjustability, rigidity , etc.

Luck