Yeah they are fun, much better than going uphill. Downhill is REALLY fun on mtn biking. But I just don't enjoy going really fast down hills. If something goes wrong while going 40+ on a bicycle, it is not going to end well haha.
speakin of fixed gear, i "tightened" my lockring down with a hammer and screwdriver, it feels tight and won't go any farther, do i still need to get it wrenched down?