i typically let any of my friends who want to drive my car drive it… when i had the manual cars… as for bikes, well i was super lenient with the 636… and now the bikes i have can put an experienced rider in his place, im a little more selective, but I have let quite a few people ride the bikes… which OBVIOUSLY poses more room for error (to be honest. i only worry about them crashing, and getting hurt, not so much damage to the bike from abuse… its built to get beat on and I’m 100% certain i beat on it more than anybody else does)