I wanted to share with everyone a project that I have been working on this last year. This thread will outline my resto-mod build of one of the Cammex team’s original ATC 250r racers from 1982. I acquired this project in April of 2016 from Keith Salyer at one of our races in Illinois. Keith had posted pictures of the chassis on Facebook and we were able to strike up a deal. Now for those not familiar, Cammex was founded by Calvin Pollet and the name is derived from the acronym Central American Micro Midget Engines and Xtras. After starting out in Midgets, Calvin started building aftermarket cylinders/heads for the 1981/82 first gen trikes. This soon turned into full performance packages for the air foolers and a Cammex racing team as well. I’ll let Keith elaborate more on the history as he was one of the Cammex team’s racers.
A little history on the chassis. This particular trike was piloted by John Day and gave the Cammex team their first big win at the OKC fairgrounds in 1982. When building the trike, Calvin was looking to replace the drum brakes on the 1981 ATC 250r for a disk brake setup. Naturally he turned to midget (kart) components to get the job done. The result was a custom built swingarm utilizing externally mounted bearings, a floating carrier, and a 1.25” keyed kart axle. The floating carrier (brake/sprocket hub) and the rear wheel hubs were custom made one-off sand castings by Calvin. This enabled the use of a standard midget axle.
Now flashing back to present day. When I received the project it was in very rough shape. It was evident that the chassis had sat outside for a number years. If I remember right, Keith had mentioned that it was already sitting outside the shop at Cammex by the time he joined the race team in the mid-80s. When I picked it up, the original motor was long gone, but the chassis and all the original custom Cammex pieces were all there. Luckily Keith had me covered on the power plant as well. I was able to work a deal him for a complete Stage 5 Cammex motor package out of another Cammex trike he had parted out. The package includes the Cammex top end which utilizes a YZ piston and rod, a full sectional exhaust, Mikuni power jet carb, and a motoplat ignition setup. Attached are some pictures from pictures from before I started disassembly.
The reason I waited so long before starting a build thread was due to how difficult it was to disassemble this trike. The years of corrosion made it extremely difficult. It took 4 months of consistent work to get the trike fully disassembled without damaging any of the custom components that are not replaceable. Once apart, the swingarm needed a lot of attention to get it up to standard. The original setup used a flat plate to hold the bearings. The bearings were then centered by the bolts that secured the plate to the swingarm. Not an ideal setup for longevity, but good for the year of racing this trike seen. There were multiple bolt patterns on the swingarm where the bearing had been mounted. It appears Calvin had played with a few different options when building the setup. Luckily one of the bolt patterns matched the modern large bearing cassettes used in kart racing today which are a much more robust mounting solution for the bearings. From there the clean-up began and parts went out to plating, powder coating, and chrome.
That brings me up to present day. The powder coat, plating, polishing, and chromed parts are back in the shop. Below are a few pictures of current state. The frame is a Metallic Blue powder coat, I had the original Cammex color blue matched in a Metallic version. The swingarm, front engine mounts, and triple trees have all been triple chromed. There is still is a ton of work ahead and more parts yet to re-finish, but for now it will get a home on the work bench next to the Cagiva. More updates to follow soon and hope you enjoy the build.