When shopping for a new bike, you'll not only need to select the type of bike that best suits your riding style, but also which frame size will fit you. Choosing a frame that is too large or too small can lead to discomfort, pain and even injury. Although height is one of the key measurements you'll need when you go to the bike shop, many factors go into finding the bike that fits you best.
Getting Height Right
To get the best bike fit, you need to measure your height accurately. Stand on a hard floor with your shoes off and your back up against a wall. Your feet should be about hip-width apart as a friend measures you from the base of your feet to the top of your head. Because bikes are measured using either the U.S. or metric system, record the number in inches and in centimeters. If your tape measure doesn't have centimeters, multiply your height in inches by 2.54 to convert it into centimeters.
Sizing up Bikes
Different bikes are measured in different ways. Most road bike frames are listed in centimeters, whereas mountain bikes and hybrids are listed in inches. When given in inches or centimeters, frame size refers to the length of the seat tube -- the part of the frame that extends from where the seat post inserts to the bottom bracket. Some comfort bikes and lower-quality hybrid and mountain bikes have sizes listed as small, medium or large. With these bikes, it can be difficult to get a proper fit without testing and making adjustments to the bike.
Matching Heights to Frames
Because height doesn't take flexibility, or leg, arm and torso length into account, a bike that fits one person perfectly based on height may not fit another of the same height. In bike sizing charts that use height, a range of sizes will be given. For example, someone who is 5-feet-11-inches tall may want either a 19- or 21-inch mountain bike, or a road bike ranging from 54 to 60 centimeters. This is why it's crucial to take any bike for a test ride before making a purchase.
Fine Tuning the Fit
If using your height isn't getting you a properly fitted bike, you should use your inseam measurement to get a better fit. To measure your inseam, stand barefoot on a hard floor with your feet about shoulder-width apart. Take a book and press the spine against your crotch, then have a friend measure from the spine of the book straight down to the floor. This number gives a better match with the measurement used for a bike's frame. Adjusting the components on your bike such as the saddle position, handlebar angle, stem length and crank length will fine tune your bike into the best fit possible.