Dorel, the parent company behind Cannondale, Schwinn, GT, Mongoose, Iron Horse and Sugoi purchased the Canadian brand Guru last year. In doing so, Dorel was able to bring into the fold a new fitting system based around what might be the most sophisticated fitting device on the market, the Guru Dynamic Fit Unit. We got a look at the Dynamic Fit Unit at Interbike and had a chance to see the basic process for taking someone through a fit.
During the Cannondale team introduction I had a chance to go through a fitting with Colby Marple from Guru. The Guru system offers two different levels of fit, one for production bikes and another should you want to have a custom bike (say a Guru) produced to your personal requirements.
The fitting began with me being scanned by a Kinect unit. Yes, Kinect as in Xbox. As it turns out, Guru’s lead software developer was one of the original developers working on the Kinect unit. The Guru software includes a database of production bikes and their geometry. Based on its scan of me, we were able to choose a couple of different bike models and it quickly showed how neatly I fall between the 56 and 58 sizes.
The Dynamic Fit Unit (DFU) is the real heart of the system. Quick release clamps allow for easy swapping of both saddles and handlebars and the cranks can be adjusted to provide riders the recommended crank length.
For those familiar with the latest version of the Serotta Size Cycle, one of its big selling points is the ability to use an electric driver to make handlebar and saddle position adjustments while the rider pedals. The ability to move smoothly through a range of possible reaches, bar heights and saddle heights is one of the two biggest advancements in fit methodology of the last 25 years, the other being the rider flexibility assessment. I had one of the original Serotta Size Cycles in my garage for about a year and I’d use it to experiment with my fit. The difference between getting off the bike, making an adjustment and getting back on vs. pedaling continuously while the bar or saddle moves is the difference between the Dewey Decimal System and the Internet. It’s just no comparison.
Where the Guru DFU differs with the Serotta Size Cycle is that servo motors in the DFU unit make precise adjustments based on keyboard inputs by the fit tech, resulting in changes of higher precision and performed at greater speed. But that’s not all. Supposing you like your bar position relative to your saddle height but you want your saddle to go up a centimeter. The DFU fitter can make the two changes simultaneously. Similarly, say you want to try a slightly steeper seat tube angle, the DFU can simultaneously raise your saddle and bring it forward while also dropping the bar and moving it forward in order to preserve the saddle-to-bar relationship.
Wait, that’s not all.
The full-on Ginsu pitch is that the fitter can rock the full position back to simulate climbing on almost any gradient in order to allow you to experience what that position will feel like on Mt. Shootmenow. And if you’re getting a mountain bike fit, you can be swung forward to simulate an ultra-steep descent to get a feel for just how much weight you’ll have on the bike’s front wheel.
My view is that a fit system is just a tool. From the gear to the methodology, a fit system is just a tool to do a job. In the hands of someone with minimal training, it might not be a very effective tool. However, in the hands of someone like Cyclologic’s Paraic McGlynn or Bike Effect’s Steve Carre, the DFU is the most powerful dynamic fitting tool I’ve encountered. This thing could make a great fitter as formidable as Peter Sagan is in a sprint.
My session resulted in a fit that I’d be willing to put my faith in. It differs from my current fit by less than a centimeter in saddle height, while the bar position was more than a centimeter higher with roughly the same reach. I should mention here that because I move between a number of bikes on an ongoing basis and between as many saddles, I’ve grown immune to small differences in ft. I had to learn to put up with changes in my fit from bike to bike, even when I’ve gone to great lengths to replicate my position exactly. Exactly just never happens. Because I’ve managed to ride well on a number of bikes with slightly differing fits, I’ve come to believe that when someone (be it fitter or rider) starts to get fussy about that last millimeter they are failing to understand the inherent adaptability of the body. And I write this with the knowing admission that I’ve suffered problems at the hands of bad fits by alleged fit experts.
I think part of the genius of the DFU is that all the rider has to go on is the feel of the fit. With no stem to look at nor the visual cue of seeing the drop from the saddle to the bar framed by the bike itself, all you can really go on is the feel of sitting in the saddle and reaching for the bar. When the original Serotta Size Cycle was introduced I was skeptical that a good fit could be achieved by a fitter simply listening to feedback from the rider. I was perhaps right to be suspicious of the original iteration, but today it’s an approach that makes terrific sense. It does require that the person being fitted talk a lot about what he or she is experiencing as the key to a good fit is communication, but even a relatively quiet person can get a great fit from a good fitter. The best can see unwanted muscle tension the way poker players can suss out tells.
Finally, I’ll grant that it might be a challenge to place your faith in this approach until you’ve experienced it. I learned to give a lot of feedback as either the bar or saddle is moving: no, no, no, not bad, okay, yes, yes, errmm, nah, no, no, no. It was interesting to me that Colby had the same reaction to my feedback that Steve Carre at Bike Effect did. They both noted that they saw an easing of tension in my shoulders just as I started to say “yes.”
Again, the Guru system is just a tool, and that goes double for the DFU. However, in the hands of a great fitter I think the DFU has the ability to help a fitter arrive at a result that the client will believe in. Why? Well the dirty little secret of fitting is that the single biggest challenge a fitter faces is getting the client to not just adopt the recommendations, but to stick with them long term rather than switching the bike back after a ride or two. The DFU provides an experience that makes the recommendation one’s own, not some outside piece of advice. When I was first trained as a fitter, recommendations were made based on a set of tables the correlated to the rider’s personal dimensions. The process was effectly: here’s what you are, so here’s what your fit should be.
The DFU, more than any other fitting tool I’ve encountered, upends that convention by making the fitting a matter of self-selected comfort. That might seem obvious to the point of naive, but really a proper fit is fundamentally a function of comfort and who can better know your comfort than you?