I'm 23, 5'3" and 140lbs. I tried riding my Dad's 750 to learn on. He had a lot of confidence in me. I did really well for a little while but when I came to a nice slow stop I had a little too much weight to my right side and I couldn't hold it back up so I slowly let it fall. No damage at all to the bike but my ego was shot and I lost to confidence to try again that day. I'm worried that a 750 is too big for me but I was wondering what others, with experience, thought.