Winter in Colorado has been cold. Damn cold. A couple of mornings it was minus 10 when I went to work. The little thermometer shows the garage was just above freezing during a lot of my fabrication. Despite that, I was able to get a lot of work done. As you can see below, the forks have been severely raked back from 27 degrees to 40 degrees, giving it a better look, at least to me. New controls arms were built and new adapters for the ball joints to connect to the triple clamps. The front part of the frame was modified to allow for a better steering mechanism, which has been the focus of my recent work. As before, I want the front wheel to turn the same amount as the handlebars, plus when the suspension moves up and down it can't create any bump steer which would make it tough to keep control of the wheel. It took a lot of head scratching and computer time, but the results were worth it because the steering works.
On the left is a cheap cardboard mockup to test the new steering concept and it worked pretty well. You can see some little degree marks which show the angle of each part to check if everything lined up.
On the right is how it turned out using real materials. Once again I used little cardboard indicators to see if everything moved the same amount. After some fussing and adjusting, the front turned within about 2 or 3 degrees of the back. If you consider my crude fabrication methods, I think that's a pretty good result.
It's built with 1" steel tubing and race-quality heim joints with opposing threads to make adjusting the lengths fairly easy. At the moment it's just tacked together but now that I know it works I can do the final welding.
It fit but after seeing how it looked I decided to try something different. It took about an hour to make the mockup but it saved a lot of time in the long run. I did the same for all of the other brackets. Cardboard is easy compared to steel.
Above you can see how the front wheel turns with the handlebars. Having the degree indicators at every pivot made it easy to adjust everything and confirm it worked the way I planned (and hoped). At right is a close-up of the indicator at the center pivot. I drew it with my cad software, glued the printout onto cardboard and taped in in place. Cheap. The drag arms are adjustable for length. The lever arms are slotted to keep the mounting holes the same distance at both ends, which is crucial to keep everything aligned.
The center pivot is just a bolt welded to the frame, with the lever arms welded to the nut. I want to use a bushing there, but at this point I need to be able to adjust the height of the lever arm to eliminate bump steer, so the bolt and nut combination works great.
Last summer I once-again went to the Mile-Hi Nationals at Bandemere Speedway. As I've said before, Top Fuel drag racing is absolutely spectacular and something every gearhead should experience. I added some new footage which can be found via the Photo & Video Gallery, but here's a little peek. Click on the photo and turn up the sound.
Here are the ball joints and the adapters for the triple-clamps. The ball joints themselves are from a 1995 Toyota 2WD pickup. I happened to own one of those pickups and the ball joints "looked" to be the right size. If they're strong enough for a truck they'll be unbreakable for my modest needs.
The adapters are mild steel and were beautifully machined by my friend TJ, who has an enviable garage. They feature the same taper as the ball joint shanks which makes for a tight fit. As shown in the photo, one adapter was already pressed into the upper triple-clamp and the other was waiting to get welded to the upper clamp (not shown). These are one of the few things I couldn't make myself.
Here's a minor triumph. When you use Google to look for "recumbent motorcycles," ProjectVF is now the Number One search result. Many thanks to all the motorcycle fans and random surfers who made it possible!
My project came up for discussion on a French motorcycle site. I hope whatever they said about me was nice.
