Ever just fall in love with a bike, only to quickly realize it’s two sizes too big for you? Don’t fall in to a financial set back by following your heart! If you’re riding a bike too big or too small for you, you are not only at bigger risk of accidents short term, the longer rides you do the higher your risk is for injuries. Knee pain, lower back pain, shoulder, wrist, and even lower leg pain can happen if you don’t have a great bike fit. Bike geometrics are very tricky and vary from bike style to bike brands and models. Even different components on the bike like stem length, handlebars and saddle height can cause pain if they are not fitted to you. Investing in a bike fit by a certified and knowledgeable bike mechanic is something that should be done as soon as you get a new bike, and annually following.
How can you tell if your bike is too big? Your crotch should not touch the top tube, and you should be able to comfortably put both feet on the ground while on top of the bike. Your saddle should also not be slammed all the way down, and while cycling, your arms should not be overreaching. If your bike is too small, your knees should not hit your arms or chest and your legs should get a full range of motion. Your seat post should not be at the very end or passing the line that most posts have.
Cycling is a wonderful sport that is of minimal impact and should not cause pain each ride. If there is, go see your bike professional at your local bike shop, and come see me to help you recover from that injury.
Source: Mechanic Mike with Let's Go Ride Bikes