How much suspension should i use on the road with mountain bike?

Question

How much suspension should i use on the road with mountain bike?

Answer 1

Thats easy. None.

Suspension is to keep the wheels on the ground for better handling, not for comfort. Since most roads are paved there is no need for suspension.

Now, if you wish to have a suspension seatpost or a heavily padded saddle then that is fine.

Answer 2

Mirage is right as little as possible. The big tires themselves offer more than enough cushion.