Originally Posted by shogun17
Fixie is useless if you want to take the mtb mountain biking through xc trails, or any trail except firetrail. I ride a fixie mtb but only for commuting, it goes freewheel for any offroad use. Try bunnyhopping logs at speed on a fixie, or navigating tight singletrack that you need to be able to manipulate where your pedals are to get through. It can be done on a fixie, but is extremely hard. Commuting/firetrail only (no or very few obstacles)=fixie. Any other offroad use=singlespeed
Not to pick on this post in particular, but you can in fact ride a fixed gear on most offroad trails. Real ones.
There are folks out there regularly doing xc races, both official and underground, on fixed gear bikes. Some of them are mighty fast. With the right technique you can ride a fixed offroad just fine.