Mine, 81, was more an evolution than a choice, plus me being cheap. My first racer was from a pocket bike group and the bike came with 48, a number still used by the seller. I just peeled them off and stuck them back on as 84 - nice and cheap. I then came to CMRA and added a 1 for 841, both cheap, and easy to change back and forth between Endurance, where I left it 84, and Sprints, which I did both of for about 7 years. Then I 'won' a 2 digit number at the Banquet and staying cheap, just threw every combo of those 3 digits I already had a bunch of stickers for at Nancy and let her assign me one. End up losing the middle digit and making 841 into 81. Worked out well, as that was also my graduation year. 81 it is.