Precision Bike Fits
Fitting the Bike to the Rider
(not the other way around)
Does your bike fit you or do you fit your bike? In other words, is your position on the bike based on the length of your limbs and range of motion about your joints and your riding style, or is it based on the equipment you have chosen or what came with your bike from the shop? Too often, I have found that the latter is the case. Many riders try to adapt the way they ride and the way they sit on a bike to the what the bike allows them to do, as opposed to adjusting the parts on the bike to allow them to ride in a position that is efficient, aerodynamic and allows them to avoid many overuse injuries related to long hours in the saddle. The other mistakes many riders make is worrying about the “look” of their bike or trying to match the position of their favorite pro.
Bad habits and damage ... The fact of the matter is that the human body is very adaptable and will learn to work in even the worst riding position over time. There have even been some very successful cyclists who have ridden in very unorthodox positions (check out old photos of Sean Kelly). Another fact is that the damage done by a bad riding position or misaligned pedal stroke may not be noticeable for quite a long time. How often have you noticed a pain in your knee or hips that only comes on when you put in some extra miles?
The goal of a good bike fit is ... to set the saddle, handle bars and cleats in a position that allows you to turn the pedals efficiently and with no damage to your joints or bones and to avoid undue fatigue. When your riding position fits you, your bones can carry more of the stress of applying power to the pedals and supporting your body, and your joints can work and track within their normal range of motion.
A precision bike fit is one that is based on ... the length of the bones and the position of the joints that are involved in the process of pedaling your bike. In order to get a precision bike fit, each segment of the limbs involved in the pedaling motion needs to be accurately measured. Short of using an x-ray machine, the best way of getting accurate measurements is by locating and marking anatomical landmarks that can be used to identify the position and shape of the rider’s bones and joints. Using these landmarks, the rider’s ideal position can be determined based on the size and shape of the bones and joints in the rider’s legs, hips, torso, shoulders, arms and feet, and how all these body parts can work together to pedal the bike.
More than one bike? Another challenge cyclists with more than one bike may face is how to make sure they are riding in the same position on whichever bike they choose to ride. It is important to avoid changing your riding position frequently because muscle memory is a very big component of a smooth and powerful pedal stroke. If your saddle height changes up and down and back an forth every time you ride, your muscles will be trying to pull up before your reach the bottom of the pedal stroke or push down while your foot is still on its way up. This lack of coordination can lead to injuries to the joints, muscles and other connective tissue as well as impaired performance. A good bike fit is one that can be transferred from one bike to the next while maintaining accuracy and precision. Remember that your position is your position no matter which bike you ride. What this means is that frame geometry should not have an affect on your riding position. Your butt should still be in the same place relative to your feet and hands.
The type of riding you are planning to do ... should also be considered when determining your riding position. The requirements of road, mountain and time trial/triathlon riding will result in a different riding position for each style. Aerodynamics, bike handling, sprinting and climbing requirements all have an affect on your riding position.
Choices ... There are many good fitting systems that use different landmarks and biomechanical measurements and calculations in order to determine the riders ideal saddle, handle bar and cleat position. When shopping around for someone to fit your bike to you, the more precision there is, and the more factors that are included in determining your position, the better. I will admit that there are probably one or two gurus in the world that could look at you and tell you exactly what needs to be changed, but the rest of us need to do some measuring to get it right.
Independent of the bike ... I would recommend that you look for a system that determines your ideal riding position independent of the bike or equipment being used and look for a bike fit professional who will take into consideration other factors including riding style, biomechanical imbalances, physical differences from one limb to the next and neuromuscular issues that may not be fixed by even the most precise setup.
Challenges ... Something to keep in mind if you are planning on having a professional bike fitting done is that the equipment that you currently have may not allow you to achieve your ideal riding position. The seat post or saddle may not allow for the amount of adjustment required or the top tube on your frame may not allow you to get to the ideal reach to the handlebars. The bike fitter will aim to get you in the best riding position, but it will be up to you to take their advice and make the recommended changes.
Old habits to break ... Also remember that it may take a bit of time for you to adapt to the new riding position. A period of low intensity riding should always be planned for after making any changes to your riding position, especially if the changes are big. Never change your position right before an important event.
Get all you can out of your ride ... Riders at every level have a good reason for having a precision bike fitting done. Riders who only get out once or twice a week will want to be sure they are getting all they can from the time they spend in the saddle and riders who compete or put in a lot of time on the road will want to be sure they are as riding as efficiently as possible while at the same time avoiding overuse injuries from even the slightest misalignment or imbalance.
Remember, your bike should fit you, not the other way around.