Is it an RST Cappa? If so, please remove it. You have no steering tube size issues. Not on a 2001 Trek 820. The top two places to spend coin on that bike are the brakes and the fork. A better fork won't bob around so much, will most likely give you a little more travel and some real adjustment options. A Judy, er.. Dart can be found online that won't kill all of your budget and will be better than the RST. Keep the low end drive train adjusted and watch your cables. I bought my friends 01 820 several years back when he desperately needed some cash. He rode the hell out of that bike and sometimes I take it out for grins. Usually I keep it for him to ride. The dumb ******* never bothered to replace the bike. It currently is stock save for the stem/handle bar, fork ( a Manitou Black I had laying around doing nothing) and XT brakes. Also better cables and housing. Enjoy your ride.