BIKE FIT: "What size bicycle do I need?"

If your bike frame size is not the right size for you, and the bike fit is not customized to your body size and type, then you will not be comfortable. Let us take you through the steps of finding the right size bike frame for your body and performance goals.


A bike size chart is a great place to start... we have several below, plus a video to help guide you.

What size bicycle do I need?

This a two step process: first frame size then fit adjustments.

 
Finding the right size bicycle frame for you will depend on the type of bike, your height, inseam length and physiology, and your style of riding. We can help you determine how you will be most comfortable by finding you the proper frame size and then adjustments of the main components in contact with the cyclist's body:
  • the handlebar and grips
  • the saddle
  • and the pedals
These 3 contact points between body and bicycle must be considered with particular care and satisfy the following standards:
  • individuality (body mass, etc.)
  • ergonomics/functionality (anatomy/health)
  • differentiation (area of use, requirements)
  • safety
The video below demonstrates things to consider in choosing frame sizes and fitting your bicycle. 
 
"What size bicycle do I need ?" First consider Frame size then Fitting the bike.
 

 
To avoid feeling cramped or awkward and make the most of your pedaling action you should ensure the bike frame, seat and handlebars are sized correctly for you.

A very good resource (though a bit simplistic) is an internet frame sizing tool here. If you are considering a Road bike we suggest using this frame sizing tool at Competitive Cyclist (though it requires more complicated measurements).

Sizing charts using your height and bicycling inseam (the distance from the ground to your crotch) can also give you a basic idea of the frame size you need for your bike. The bike measurements are given for the frame of the bike, which, for road and mountain bikes, is the distance from the top of the seat tube (rather than the seat) to the center of the bottom bracket. For a mountain bike you normally require a frame 10-12 centimeters smaller than a road bike. Remember the chart is a guideline only and the final size you choose may vary.
Take a look at the bike size chart below to find the right sized road bike for you. Know your height and inseam measurements in order to match the size frame that will be most comfortable for you. Of the two measurements, height and inseam, inseam is more important. Also look below: you can download a very detailed sizing chart for Road bike fit, and an excellent article on Fitting a Bike to your own personal needs.
Mountain Bike Size Chart
Mountain bikes are usually measured in frame size (inches), the distance from the center of the crank to the top of the frame at the seat tube.

Next consider Bike FIT.

The Foot and Pedal interface becomes critical to comfort and efficiency when one uses shoes that clip in. Read more:
  
What else do I need to know to find the right bike fit after considering a Bike Frame size Chart? Let's think again about the three main components that come into contact with your body and how they should be positioned:

Handlebar and Grips: The position of the handlebars is very important to your comfort and safety.  The wrong angle can lead to back pain, shoulder strain or wrist soreness. On racing bikes, the general width of the handlebars is the same as your shoulders, and on mountain bikes, the handles are slightly wider than your shoulders.

Handlebars can also be placed at different heights. On road bikes handlebars are about an inch lower than the top of the saddle, but mountain bikes need a lower center of gravity for comfort and balance. Also ask for help in finding the minimum insertion mark so that your handlebars are fixed no higher than the insertion mark.

Saddle: While some cyclists may chose a saddle that is tilted slightly, you may want to try on that is level enough so that you don't slip forward or backward. You may need to make some adjustments as you ride to get the feel just right. Generally, the seat should be positioned so your feet will rest naturally above the pedals. You shouldn't have to move from side to side to reach the pedals.

Pedals: You want to make sure that your riding motion is smooth and efficient, and you can accomplish this with clipless pedals or toe clips. When you clip your feet in, each pull or push motion makes the bike propel forward more smoothly. Cage-like toe clips let you wear regular shoes, but make the pedaling motion more cumbersome.

Can I check all this myself? You really can't make an accurate fit by yourself - it's too hard to determine lengths and positions. At Hart's, we not only have an objective eye, we also have years of experience with many types of frames and bike components; and we keep up with the latest scientific and methods of fitting you for comfort, safety and performance. Next time someone asks "what size bicycle do I need?" remember to start by thinking of the frame.