EVERY BIKE SHOP needs a “Fit Kit” as the basis for sizing and fitting, regardless of what other bike fitting tools or systems are used.
The Fit Kit System is based on the fundamental premise that anatomical proportions provide a reliable, predictable guideline to selecting a bike size, and establishing an initial riding position, and a starting point in the process of fitting a bike for a cyclist.
The Fit Kit contains the measuring tools, which used together with one of our apps, will estimate the bike size and initial saddle height.
The primary anatomical measurements are:
- Foot length
- Inseam length
- Torso length
- Arm length
Additional measurements can include femur or lower leg length, and shoulder width.
The two primary outputs of the Fit Kit System are a projected bike length or reach, comprised of the effective top tube length and stem length, and a seat height range.
The proprietary data used in the Fit Kit Sizing Calculator is not a formula based on mathematical algorithms, but is research-based empirical data gathered from measuring thousands of cyclists.
The projection of bike length based on the anatomical (hard) measurements can be refined by taking into account a “soft score” derived from responses to 4 simple questions:
- Age
- Flexibility
- Riding Style
- Pre Existing Conditions – physical issues or injuries that place further constraint on the riders positioning.
The projected seat height range and frame size is not based on a proportion of the inseam length, like the well known “Lemond Method”, but takes into account foot length as well, which is an integral part of the length of the lever from saddle to pedal. A specific seat height is not prescribed due to variations in shoe, pedal, cleat, cleat position and pedaling style. However a starting point is suggested which can be further evaluated and refined.
Using the Fit Kit Systems S.T.A.D.T (seat tube angle determining tool) uses the relative proportions of femur and tibia to overall inseam length to project the steepest recommended seat tube angle.
Learning our bike fitting process will give more information for completing the set up on a new bike (initial bike fit), or solving issues related to a poor bike-body relationship.
As the collective knowledge and understanding of cycling bio-mechanics and performance factors has increased over the years, the use and application of the Fit Kit System has evolved. It is used most commonly and accurately now as a Sizing System, to ensure a rider is buying / renting / riding a bike of an appropriate size, with sufficient allowance for the bike to be adjusted (fitted) to suit the rider.
Digital sizing systems assess body joint angles to determine a suitable frame size. These systems require investment in an adjustable size cycle, video or motion capture technology and associated software, and frame finder software.
The Fit Kit is an analog system of tools and data that is high quality, low cost, portable / store-able, reliable and easy to learn to use. This system can also be used in conjunction with other bike fit methods to establish an initial position on a size cycle.
The Fit Kit has been in use for well over 30 years by bicycle retailers and fitters around the world. According to bicycle retailers who have and use it: “This is all you need. It is simple. It works. Every shop should have one.”