The Right Stuff for the Job
At Co-Motion Cycles, turning ideas into bicycles is more than just giving someone an order. The bicycles we offer are a reflection of the very practical way we do things. In fact, every one of our bicycles is evolved from our past experience - from the bike we ride ourselves to those we build for our customers. We began like many other frame builders - building strictly custom bicycles. As time went on we developed stock models based on what our customers were ordering. We tracked our fitting data, and paid attention when customers asked to change an angle here or there, or accommodate a new component or innovation. Now more than ever, we use customer input to influence how we'll continue to push the evolution of the bicycle.
The tubing that your tandem is constructed from plays a huge part in the ride of the bike. Co-Motion tandem tubing is continually evolving to deliver a comfortable ride while possessing incredible lateral rigidity. Every tube, from the tapered S-bend chainstays to the double butted down tube, is thoughtfully profiled for optimum applications. Our continuous length tandem top tubes are butted at each intersection - at both ends as well as in the center section, an expansive and complex process we call zonal butting. If you count the number of wall thickness zones, our tandem top tubes would be considered quint-butted. Interestingly , these tube profiles are also asymmetrical, since the stoker and captain compartments are quite different. We use the term zonally-butted because it clearly defines the intention of bicycle tube design, which is to reinforce the tubing at each intersection, while lightening the less-stressed section in between and improving the ride quality of the bicycle.
On our Co-Pilot bikes, ones equipped with S&S couplers, we have updated the profile of the tubes to better support the installation and placement of the couplers. No other company has gone to the extremes we have to design the bicycle around the bicycle torque coupler to improve travel-ability. All of our tube designs are exclusive to Co-Motion and unavailable to other manufacturers. This includes the Reynolds 725 and 631 tandem tubes.
Our aluminum tandems are made from custom 7005 aluminum we call ACM Ultra7, tubes that share our zonally-butting designs and methodology. To create a better riding and more precisely constructed aluminum frame, we use continuous large-diameter top-tubes, rather than bulged or two-piece tubes. Every Co-Motion aluminum frame is put through an artificial aging process to strengthen the aluminum. You've probably heard the term heat-treated before. This technique reintegrates the alloying elements, aggregated from the welding process, back into the crystalline structure of the tubing.
A key element to making Co-Motion tandems and touring bikes handle better is our steel fork. We re-engineered these forks from the ground up. Our machined steerer tubes make a superb foundation for our tapered fork blades. The steerer tube and crown is machined from a single piece of Cro-Moly tubing. For unsurpassed strength and precision, the steerer tapers to a larger bearing race area, and increases in diameter again at the fork blade attachment area. We designed our fork blades specifically for tandem use, because the available generic mountain bike fork blades simply wouldn't do. Shaped for excellent road compliance with ideal lateral rigidity, these large diameter tandem blades have tapering wall thickness from top to bottom. They've allowed us to build super strong and durable forks for tandems and touring bikes that are unrivaled.
For our special carbon forks, designed intensively here for specific applications such as our new thru axle gravel tandem fork, the process is unique. We model the entire monocoque structure in a 3D design program called Solidworks. Designs are submitted to our carbon fork manufacturing partner. Testing parameters for tandem forks are not standardized like they are for mountian bikes or road bikes, so we had to create tandem standards that rise above any other. Testing is first done virtually with finite element analysis and virtual modelling before prototypes are built and tested. At every step, designs amd material choice, carbon strand orientation, dmmensional profiles and even mold release features may change before the final product can be produced.
We are committed to choosing our materials and our material-proving partners well, from the organizations who manufatcure the tubing we design for our bike line to those from whom we may purchase a simple item like a socket head cap screw. Each of our material suppliers is an important component of what in the end becomes your bicycle, and it our mission to make your bike surpass your expectations.