How to choose a bicycle size
Choosing a bike size depends on the type of bike, your height, riding style and preferences. A properly fit bike will be more comfortable, more efficient and more fun to ride. Provides evidence My Bike This bike size for our customers gives general advice on choosing the right size. It is a guide only and we always recommend that you visit one of our stores or contact one of our experts using one of the options from the Contact Us page.
Measure your height
To find the right size bike, you'll need to measure your height and inner leg. For your height, stand against a wall and mark the wall with a pencil so that it is level with the top of your head. Then measure from A to Z to the mark (having an employee help might make this easier). In order to measure the inside of your leg, stand against a wall and use a book and hold it between your legs in the groin area making sure it is flat against the wall. Measure the height from the book to the floor. (Again it may be easier to get help from a friend.) If your height is on the cusp of a size range, your reach is often the deciding factor in determining what size you want. To find out if you have a short or long reach, you'll need to measure your Monkey Pointer. This is your arm span minus your height. If you have a positive monkey indicator, go to the larger size, or if you have a negative monkey indicator, go to a smaller size.
Choose the size of the bike type and bike:
What type of bike you choose will affect the size of the bike you buy. The type or style of riding you do will also affect the size you need. For example, a mountain biker who wants to ride more aggressively and desires a more maneuverable bike may prefer a smaller size than he would normally take. Likewise, a cross-country racer looking for a flatter, faster mountain bike might prefer a larger size than usual. There is no exact right or wrong size, it all comes down to personal preference and what feels comfortable. All the different types of bikes are explained in our buying guides here.
How are bicycles measured?
Bikes are measured by seat tube length. This measurement is usually from the center of the bottom bracket (BB) or the center of the bolt that attaches the crank arms. This varies by brand, some scale at the top where the top tube meets the seat tube, or even the center of the top tube. Mountain bikes are measured in either inches or descriptive sizes (small, medium, etc.). Road bikes are in inch or descriptive sizes as hybrid bikes can be one of the three. Bikes also get bigger as they get bigger (relative to frame size) but different brands can be inherently taller or shorter than others.
Stand Over Height is the height of the tire off the ground. Stand measurements at height above the top tube. Ideally, you want at least 2cm of clearance between you and the frame. In theory, standing tall is your leg measurement minus 2 cm. It is worth measuring your inner leg with your shoe so that you can stabilize your stance over the height. If you need to jump out of the saddle quickly, the clearance between you and the frame will prevent any injuries.