Malle mile is an event filled with quirky motorcycles. But if there’s one thing you wouldn’t expect to see there, it’s a tricycle BMW R100 wrapped in a classic car-like body.
We discovered this amazing oddity while wandering around Malle Mile’s festival grounds last month. It looks quaint at home against the backdrop of the Lincolnshire countryside, with its classic sci-fi vibe. Naturally, we had to learn more — so we followed the builder, Tim Cumper.
Tim is a day-to-day prototype model maker, but he works on bikes and custom furniture after hours. His workshop name is particularly fitting, given how wild his imagination is; Cumpert Contraptions.
“The tricycle was inspired by the pre-war racing cars that I was a big fan of,” he told us. “When I started this project in 2012, Morgan had just released their new 3 Wheeler. But the main motivation for this project was that I wanted to try my hand at aluminum sheet fabrication.”
Underneath that whole body is the skeleton of a 1993 BMW R100R Mystic, combined with the front end of the ATV. And as you can imagine, it takes some technique to get it right. Tim explains: “The front end of the quad is square and the BMW frame is round.
Fortunately, both frames are about the same width, so the main job is to line them up. Tim started by fitting a pair of Austin 7 wheels laced up front, then he propped up both ends to stack them and measure the wheelbase. Some ingenious TIG welding sawed the rest.
Most of the ATV’s front end is still intact, including the steering linkage, swingarm and suspension (though Tim plans to upgrade these). ATV’s disc brakes are also promoted, while the rear still uses BMW’s drum brakes and wheels. The rear shock is a Hagon part that has been fitted to the sponsor’s bike.
Another really well-hidden modification is the new mounting position of the boxer engine. Tim wanted to evolve it forward, so he built new mounting points for OEMs via bolts to attach. He then built an additional link to transmit power to the stock drive shaft.
What? To be on full display, is BMW’s refined bodywork. Tim created many concept sketches for his tricycle – so, once the chassis was complete, he began to refine his concept using CAD software.
Having a digital rendering is useful in many ways. First, it allowed Tim to CNC machine a 1/3 scale model of his idea. Next, it helps him create wooden carts to hammer the boards on.
“This was my first sheet metal project,” says Tim, “so I designed the shape of the tricycle to be mostly simple forms. Most of the body is made of rollers, while the front grill and side covers are mounted on MDF boards, with a bit of an English wheel to smooth things out. The most complicated part is the back part, which is made of about six parts. “
Tim also admits that he built this car for looks rather than practicality. Each panel bolts to the inner frame via a multitude of dome head screws. This means that even the most basic services can take a while.
The need for a powered screwdriver aside, the bodywork is breathtaking, with hints of Star Wars vehicle design. Tim has also added some elegant details — like the CNC-machined side skirts that hint at the iconic BMW 507.
Above the unmissable front grille is the newly replaced Kawasaki Versys windshield, mounted on custom positions. At the back are seat cushions and upholstery from a Triumph Bobber, mounted on a handcrafted pan. In the middle are countless compact lines that show how well this machine is cared for.
At the top, Tim’s original parts are retained like the switches and tachometer, giving the bike a vintage vibe. The tacho has been reassembled into a bulge panel on the top of the tank, with the original BMW key located just below it. If you’re looking for the fuel cap, it’s between the handlebars and the display.
Other changes include a Daytona speedo, a Honda brake lever and a full rev with a Motogadget control box. Below is a Yamaha BT1100 silencer — but Tim only recently fitted these, as he took the bike to a noise-limited event.
Tim calls this a shed build, but he’s unnecessarily humble – especially when you consider that he did everything on this project himself, save money. He was also honest about the bike’s capabilities…
“The handling is odd at best,” he admits. “It will lift one wheel when cornering, so you need to shift your weight toward the inside wheel when turning.”
“I have a list of mods to try right now. I think the saddle needs to be lowered and the handle bars raised a bit to make it easier to move around and see where you’re going, plus I wanted to try an anti-roll bar at the front. “
“Also, some other practice would be helpful.”
Cumpert Contraptions | Instagram | Photo of Gregory George Moore
