The best way to determine the correct bicycle size is to try one in a local bike shop. However, this isn’t always possible, and you might be looking for a bike on eBay or somewhere online.
A competent bike shop can assist you in determining more than simply the frame size. They may also help you decide your ideal seat height and posture and whether your reach to the handlebars is adequate for comfort and control. You can typically pay for a bike fitting at a decent bike store even if you didn’t buy the bike there, and it’s often worth the money if you plan to ride for more than an hour at a time.
Even if you don’t buy your bike from that shop, it’s OK to ask for bike size advice if you’re already spending money there on accessories like a helmet, tubes, a bike bag, or gear. However, you may walk into a bike shop and have someone assist you in determining your bike size chart.
Size Chart For Road Bikes
Bike Size / Height / Inseam
XS (extra small) 49 cm bike, 5′ to 5’4′′ inseam under 27′′
5’4′′ to 5’8′′ tall with a 27′′ to 29′′ inseam S (small) bike 49 cm to 54 cm
M (medium) 52 cm to 56 cm 5’8′′ to 5’10” with 29′′ to 31′′ inseam
L (big) 54 cm to 58 cm bike 5′′10′′ to 6′ with 31′′ to 33′′ inseam
XL 6′ to 6’3′′ inseam 33′′ to 35′′ (extra large) Bike size ranges from 56 cm to 61 cm.
XXL 61 cm bike or bigger for 6’3′′ to 6’6′′ with 35′′ and higher inseam
Check to see if the bike is for women or men after you’ve restricted your search by frame size. While the two may appear identical at first glance, those designed exclusively for women feature geometry that better supports women’s typically shorter height and upper body measurements. Thankfully, the days of a “women’s” bike being a men’s bike with a pink paint job are behind.
My adult daughter and I, for example, have the exact inseam measurement, but she is 5’2′′, and I am 5’7′′. She can straddle and, in a pinch, ride my road bike. However, because her torso is shorter than mine, doing so for an extended period puts her in an uncomfortable stretched-out position. Although her bike is in the extra small category and abundance is in the medium, both are built for women.
All of this being said, the most perfect bike frame for you fits your physiology. As a result, some women may choose to ride a “men’s” bike and vice versa. So, if your body proportions are unusual, don’t assume you have to ride a bike that isn’t a good match for you. Any modern bicycle has the potential to be “unisex.”
It is important to know about the bike size chart. Once you have a bike with a suitable frame size for you, you may fine-tune the fit by altering the saddle height and fore-aft position of the saddle. The stem can be swapped out for a shorter or longer one if the reach to the handlebars is too close or too distant. If necessary, even the crank arms and brake levers can be swapped for a different size. The geometry of the frame, on the other hand, is fixed, so get it right from the start.