I'm looking to buy one of these:

http://www.evanscycles.com/products/...le%20bad%20boy

I was wondering if any of you guys have one (or something similar) and could advise me of which frame size to choose?

I'm 5 feet 9 inches with an inseam of just under 32 inches (31.75). I feel a medium may be slightly too small whilst a large slightly too big!

Any help would be much appreciated as I'm completely new to this!