Besides the slacker angles most people mention, a dedicated DH race rig will have a single-ring setup with a DH chain retention system. A Freerider will often ave a two-ring setup of some sort with a granny gear for climbing. Also, a full-on DH rig might get away with using some lighter-weight parts to save weight, because the spares are at the bottom in the pits. On a freeride rig, you gotta go stout, 'cause if you pedal it in, you have to pedal it back out too.
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Originally Posted by Mark Twain
"Don't argue with stupid people; they will drag you down to their level and then beat you with experience."