Mountain biking is one of today’s most popular forms of cycling. They offer the ability to ride nearly anywhere, paved or not, and are an outstanding means of exercise. If you plan on purchasing your own mountain bike, there are some mountain bike sizing recommendations that should be taken into consideration.
The frame is a very important mountain bike sizing consideration and should be one of the first things you check when purchasing a new bike. As a general rule, most frames sizes are based on your overall height and the length of your inseam. This, however, is not the end all, be all of frame sizing and is simply a base from which to start. The length of the top tube on a frame can affect the performance of the bike, with longer tubes providing a smoother ride but less agility. The length of the seat tube can also affect your overall stance on the bike.
Crank length is also important for proper mountain bike sizing. The crank is the part of the bike to which the pedals are attached and the length of these parts can affect the efficiency of your pedaling as well as your overall comfort. A good rule of thumb to use when looking at cranks is that they should be approximately eighteen percent the length of the distance from the top of your femur to the floor. It is important to keep in mind that this is not a hard and fast rule when it comes to sizing, and slight variations are common.
Saddle height and positioning should also be taken into consideration. Out of all the different techniques used in mountain bike sizing, the saddle is by far the easiest to adjust. The saddle height should be adjusted so that you leg is still slightly bent when at the bottom of the pedal stroke. Too high of a saddle will cause your leg to be completely straight at that point, and will inevitably reduce your performance and will become extremely uncomfortable on a long ride. Conversely, if the saddle is too low, your legs will not be able to put their full force into each pedal stroke and you will lose pedaling efficiency.
The saddle and handlebar positioning can be variable depending on what you’re trying to accomplish. Most mountain bike sizing recommendations are designed for comfort, but can be changed for performance. Adjusting your saddle and handlebar positions can affect both aspects. For instance, by putting your saddle and handlebars into a higher, closer together configuration, you can create a higher level of riding comfort, but you will lose any aggressive handling performance. Using a lower, wider handlebar/saddle configuration will give you better performance at the expense of a comfortable ride.
With the exception of the frame, all other mountain bike sizing adjustments can be made after purchasing the bike. This means that if you buy a used bike with an acceptable frame, the rest is easy to customize to your requirements. Cranks, saddle posts, handlebars, and just about any other component can be purchased through nearly any bike shop and added to an existing frame.