I have the opposite problem. Bought a used Boulder at the bike shop for my GF and I now know it is too small. 14" frame and she is 5'9. Beginner mistake and I think the LBS should have mentioned the size. Have the seatpost cranked up and a steerer extender so it's ridable to a degree. Friend says I need get rid of the knobby tires for her but I'm reluctant to spend any more on it because I know it will never fit her correctly.