There are many factors that effect bike fit and there is no substitute for a professional bike fit to help you make the right choice. If you can't get to a bike fitter, then you can use an inseam measurement to help us to figure out which size frame will fit you best.
You will need a hardcover book or notebook, tape measure and pencil.
- Stand against a wall (with your bike shoes on if you have them).
- Straddle the book, spine up, to mimic sitting on a saddle.
- Use the pencil to mark where the top of the spine of the book meets the wall.
- Measure from the mark to the floor. This is your inseam.
- Repeat the measurement another time or two to make sure it’s accurate.