If you’re going to loan the bike out, the only thing I would suggest upgrading are those TekTros. Had a pair on my Iron Horse, which is my loaner now, and I could never get those damn things to work reliably. Considering some one is riding my equipment I feel they should be able to stop safely, especially if they are green to the sport. Some Avid BB7s and you’ll be in good shape for relatively low money.