SINGLE SPEED DIRT JUMPINg MOUNTIAN BIKE FOR DOWNHILL BIKE?

Question

DO PEOPLE USE IT FOR DOWNHILL

Answer 1

I have seen one-speeds used in downhill.

Answer 2

Sorta......and really it's only the burly types (or the masochistic types) that do it anyway.   There's a popular "freeride hardtail" kind of bike available these days that has geometry better suited for downhill riding.  Actual jump bikes have steeper angles for better maneuverability, and a lot of them also have several little "street" or bmx features that aren't such a good idea on a fr/dh bike.  

Any hardtail on a downhill course can be dangerous if you aren't highly skilled, or if it's *too* rough with a lot of rooty sections or rockgardens.  Even the best riders can get bucked on a hardtail.   A 4X course or smoother downhill run might be a lot of fun on a hardtail with a decent fork.  You'd definitely appreciate the slack geometry of a freeride version rather than a legitimate jump bike, however.  But....you can learn to ride any bike in most situations, so give it a try if you have the chance.   :o)