It's been a hot summer in Denver with a lot of distractions (see below). As such, only a small amount of work was done on ProjectVF. A crude version of the inboard suspension was built and worked better than hoped. Unfortunately, the raked forks turned out to be a problem and have to be redesigned and rebuilt. As I've often said, that's the way it goes with a trial & error design, and why I've gone to so much effort with a prototype. When the prototype works the way I want, the final bike should be just about perfect.
At right is how the frame and front suspension look at the moment. You can see the forks are raked a little bit steeper than on the scale model. It looks pretty good but has the same problem as a chopper, mainly how difficult it is to turn the front wheel when the bike is at rest.
Once you get going a few miles an hour it turns as easily like any other motorcycle but at a full stop it take a lot of effort. With the motor and everything else in place, this would be a real nightmare. Ugh.
However... the trail and rake worked well together and that in itself was a success. It matched my research and proved that no matter how the forks were raked, the trail can be set for perfect steering.
At right is a screen capture of a video I put together. It shows the entire run and features a great song from the 70's, so make sure your speakers are on. There are two versions depending on your download speed and patience: 320 x 240 at 3.3 mb here or 640 x 480 at 12.2 mb here.
The shock is mounted horizontally beneath the steering assembly. One end is attached to the frame and the other end is connected to a rocker arm. The bottom of that arm pivots on the same centerline as the lower control arm. The rocker arm is connected to the control arm with a bolt that can be lengthened or shortened as needed to adjust the ride height.
This is similar to an inboard suspension system used by race cars or high-performance sports cars. The primary advantage for cars seems to be a matter of contention, at least as far as I found online. Here's a link to an amazingly technical website which explains how an inboard suspension works, plus details a complex computer analysis program. Take a look.
For me it solves the problem of where and how to mount the top of the shock without affecting the forward view of the rider, as well as not blocking the radiator or the engine's exhaust. Just as important, it lets me adjust the ride height once the engine and bodywork are added. This was sorely lacking in the previous suspension design since the shock placement was just as guess, and a bad one at that.
This test version is extremely crude and is on just one side, but like so many areas of this project, it gave me a chance to test the design without spending a lot of time or money. Now that I have the results, I can design a better version with proper bushings and connections to use with the final bike.
As shown in the previous update, I decided to switch from the Interceptor engine and chain drive to a Sabre engine with a shaft drive. The engines are basically the same, except the Sabre spins in the opposite direction which was needed to make the shaft and associated gearing work better. Go figure.
The shaft eliminates the need for a very long chain, which would require a tensioner to reduce backlash. A shaft also allows for a larger fuel tank and needs zero maintenance.
The frame has to be redesigned to use the swingarm mounts, a new mount for the monoshock and a longer driveshaft. It's a lot of work but well worth the time and head-scratching.
The Bonneville Salt Flats once again called my name. I'd like to say that I was able to break my previous runs, but I didn't, mainly because I don't have a car. The owner of this 200+ mph beauty was kind enough to let me sit inside and imagine what it would be like to drive across the salt at an insane speed.
As always, summer would not be complete without a day at the Mile-Hi Nationals at Bandemere Speedway. The cars and dragsters leave from a standing stop and reach 300 mph in just four seconds. That's less time than it took you to read this sentence.
I wish they had a two-seat version for thrill seekers like me. I'd pay dearly to experience that sort of rush.
Click here for the funny cars and here for the final round of the dragsters. Turn up the sound.
Here's one of the reasons the project fell behind schedule. Late winter storms are not uncommon and this one dumped over a foot of snow overnight. Although it made city life a little tough the next day, it also provided some fresh powder in the mountains and I was quick to head up with my snowboard. However... a bad fall hurt my back and left me limping for a few days. Such is the price for getting a little too aggressive. I'm 49 and don't bounce as well as I used to, but that doesn't mean I'm ready to quit.
This bike was the biggest distraction of all. It's a 1975 Honda CB360 that I bought and turned into a cafe racer.
The plan was to do a quick makeover and have something fun to ride around town, but one thing led to another and I ended up doing a complete frame-off restoration. Nearly everything was replaced or modified in some way. The starter motor and battery were eliminated, the air boxes tossed, all of the cables and seals and bearings were replaced, and on and on.
The end result of 600+ hours of labor and quite a few $$$ is this little jewel. It still needs a few things and some minor adjustments, but it's a blast to ride and turns heads, and is certainly a great addition to my fleet of bikes.
The downside is if I'd put all the time and effort (and money) into the recumbent, I might have been able to adapt the frame for the new engine and drivetrain and actually ride it under power. Instead I got sidetracked by a project that got out of control. Bummer.
