I was exploring the possibility of using Polyurethane kick scooter wheels on a pedal quad idea I had in mind, but before buying all four wheels I purchased two on Ebay and went about creating a test bed FWD trike. I knew it would be a rough ride so I opted to spring the rear end using parts from an old BMX bicycle.
I used rapid prototype techniques to build this little guy. Normally you would spend days rendering a design on Auto cad and make a Jig for welding the frame. Here I just laid out the basic components, guestimated the best seat location, wheel base, rear wheel spread, aligned parts as best as I could and crossed my fingers before welding.
The front 16″ three speed wheel came off an old ‘freebee’ folding bicycle I’ve had for years. The crank, front forks and head set came from a $10 garage sale mountain bike and the seat and tubing I had kicking around the shop. The handlebars came from my old PAVO enclosed trike that I dismantled a while back for no good reason.
The first test ride was fun but the plastic seat was poking me in all the wrong spots, so I replaced it with this cheap cushy seat I found in the fishing department at Walmart.
On the second ride I notice my legs were spread out like a cowboy to avoid smacking my knee caps into the lower part of the BMX handle bars, plus I had problems with the goose neck slipping in the steering head. Here you can see the mods I did including using the mountain bike handlebars and goose neck.
A one inch tube was bent and welded to the front frame assembly. The modified stem adds support to the new boom and also allows me to slip off the front assembly for maintenance. This close-up also shows my crappy welds. I was out of practice, my cheap harbor freight self darkening welding helmet quit working and I was low on gas. Notice the tire clearance too. Luckily the tire doesn’t rub on the frame. Oh well. It’s a prototype.
I decided to paint the frame and add some accessories. I just might use this rig on the paved bike paths near where I live.
All in all it turned out to be quite a comfortable ride. At just 32 pounds it accelerates fast, and the front wheel drive set-up doesn’t sway too badly after you get going. I can even ride hands free. I was thinking of adding my Nuvinci variable speed 20″ wheel to this rig, but I think I’ll save that wheel for a new model in the future.
I still need to do more test rides, but I feel hopeful that these little wheels could handle the shear forces that a non leaning quad would dish out. Yet another project in the future…