I've done a couple of tri's before (1990's) and am interested in getting back into the sport. Since my last tri, I gave my Trek 2300 to my eldest son. Now I have an old Dawes 10 speed, a Trek 800 mountain bike, and a Sun Recumbent. I know they have "fat tire" divisions at some tri's, but could I ride the "bent"? Or, do I have to get the old Dawes up to speed? Thanks for any info!