Don’t confuse bike “sizing” with bike fitting. When you purchase a new bike, the sales person will do their best to see that the bike is the proper size for you and then set you up on the bike by adjusting your saddle height and forward aft position, and off you go. Interestingly enough, most people who roll out of the store on their new wheels are so high and the perfectly functioning new bike feels so good they are typically beyond content. However once the honeymoon is over and it’s back to putting in the miles, it is not unusual to notice a few minor inconsistencies that you did not notice while you were still “under the gas” so to speak.
It may be that you begin to notice some discomfort that begins to nag at you. It may come from the knees, the neck or low back. It may be numbness in the hands or crotch, regardless these are signs that you are not communicating well with your new machine. There are five contact points between yourself and your bike, two hands, two feet, your butt and all of these points interrelate to comfort and let’s face it, if you are not comfortable, you will begin to become reluctant to ride. The very thing that used to give you pleasure is now giving you pain.
The process of “fitting” a rider to their bike begins with careful identification of what is working and what is not. Before we begin this process of matching the bike to the rider we first take careful examination of the riders’ movement patterns. Observing the way they walk, measuring leg length, range of motion and flexibility. We interview the rider to gain insight into their riding history, past injuries and current discomfort. We consider the needs and wants of the rider; what their ambition is, if they race, how often etc.
Based upon what we learn from this careful inquiry we set about developing a fitting strategy, then, for the first time during the interview we ask the client to mount the bike. While they are on the bike, we begin the video, recording the initial postures and cross-examination of angles and the general relationship of the bike with the rider. Many of the initial findings are obvious.
As a rule before we make any modifications, we ask the rider to dismount and review the video with us and discuss what we see and what we feel should be the first adjustments. Then the adjustments are made, typically only one or maximum two and then the rider remounts, the video begins again and we analyze the changes made. This process continues until most of the obvious faults are corrected from a side view. Then we begin analysis from the frontal view incorporating video and laser beams for precise measure and freeze frame review.
This frontal view reveals the most crucial contact points between the rider and the bike, the foot / pedal relationship. Because the pedal fixes the leg into a specific path this connection requires grave detail to minimize misalignment. Most pedal systems allow for a bit of float which is important to minimize forcing the knee and ankle into potential bio-mechanical conflict, however, this float allowance only addresses a fraction of the alignment issues.
One of the advantages of dynamic video analysis is the clarity in which we are able to identify compromise at the knee, ankle and hip. With a frame by frame analysis of cause and effect and painstaking attention to detail, we are able to resolve over five points of concern.
The most overlooked consideration with most fits is the rider’s unique forefoot angles.
Studies have revealed that over 85% of the population’s natural forefoot angle is “Varus” with around 7% being “Valgus” and very few have a neutral forefoot position. This presents a unique problem to the fitter in that all pedal systems are flat or neutral. As depicted in the next image, the outcome of an excessive varus forefoot results in poor contact with the pedal. This outward pressure on the pedal is followed by a concomitant inversion of the knee on the down stroke and eversion on the upward stroke. This faulty movement pattern appears like a wobble at the knee, repeated for thousands of pedal revolutions. This abuse is the culprit behind the majority of cycling injuries. Once we have corrected these collective alignment problems the rider is able to garner the benefits promised through ownership of riding an amazingly well crafted bicycle that is now tuned to match the geometry of the rider.
I tell my athletes all the time; “of all the services we provide nothing is more instantly gratifying than a great bike fit. It pays you back immediately”.
We provide dynamic video supported bike fits in our Camarillo facility by appointment. Contact us for details 805-484-1347 or firstname.lastname@example.org