Commuting - it's about half an hour from my house to work on a bike. I last had a Ridgeback Comet (from '03), I think it may have been 17", and although the saddle height was fine, I found I had to hunch my back and stretch my arms to reach the handlebar properly, as well as feeling strain on the outside of my wrists because of the angle of the handlebar. I don't know whether that's actually a bike frame size problem, or something else.

I don't mind whether it's new or used; I spent around £350 - 400 on the last one and it was then nicked, so I probably want a slightly cheaper bike this time, just in case. Although I do want something good enough to use every day, and the aluminium frame was good, I thought.