GURU Dynamic Fit Unit

Most people who are familiar with bike fitting are aware of what a “fit bike” is. If you are a cyclist who has not been exposed to the fit bike this will help educate you on the details of what they are and more importantly what they can do for you. In a relatively small industry like bike fitting there are only a few manufacturers building machines capable of being labeled a fit bike. It is also important to differentiate between a “sizing bike”(static) and a “fit bike”(dynamic). In the early years of fitting there were a few companies like Serotta, Calfee, Waterford and a few other building jigs that could be adjusted to simulate a variety of bike sizes and geometries. These are static sizing bikes that need to be dismounted by the rider to adjust things like top tube length, saddle height among other things before being remounted to try the new position. These devices were revolutionary. It allowed fitters to do a pre-purchase sizing to determine what frame size was needed for the rider. Other metrics could be determined like stem length and frame geometry. The downside to these static bikes was the process was time consuming and sometimes frustrating to operate. There came a point in the evolution of bike fitting where someone built a true or “dynamic” fit bike. The dynamic fit bike can be adjusted while the rider is aboard and pedaling even at load. There are a few of these on the market today from companies like Purely Custom, Exit and Retul among others. The dynamic fit bike I use in the Cycling Solutions studio is the Guru Dynamic Fit Unit (DFU). What makes all of these dynamic fit bikes truly amazing is the ability to quickly move the handlebars or saddle in space while a rider is able to feel the difference in real time. Then being able to quickly go back and forth between positions to immediately feel the difference without having to wait for wrenches and tools to be used to move a contact point. This innovation truly changed the way bike fitting was done. The features that set the Guru DFU apart from the others are primarily two things. First the DFU is computer controlled. This is nice in that once calibrated, it can take the measurements of the position without needing to physically measure with a tape. It can also allow the fitter to make changes while standing at a distance to observe the rider as the contact points move. Second and perhaps most importantly, once the final position is established the X/Y coordinates of the handlebar and saddle position in space can be cross referenced with a vast database of bicycles from several model years and manufacturers. This allows the person to be fit to the proper bike instead of fitting a bike to a person. It also makes it possible to look at a variety of cockpit options. Do you want a stem at 100mm x 6degrees? We can search for bikes that fit only within those parameters. Or would you rather know all the bikes with stems from 80-120mm that would work for you? The possibilities are seemingly endless. Just imagine that first ride on your new bike, perfectly set up to your pre-purchase fitting coordinates, being an immediate extension of you.    I still see far more fittings where people are getting their current bike set up for them instead of the other way around.