Is this guy nuts or what?
Remember that movie "Honey I shrunk the kids"? Where the dad was this nutty inventor dude and his kids were constantly embarrassed of him? Well, this afternoon Cody got off the school bus shaking his head... I guess all the kids on the bus caught a full-on view of me tooling around the neighborhood in my pink tailed, green fiberglass machine.
You want to know what that the hell that is right? It looks pretty funny, but it works like a charm!!!! Check out the marked up photo below:
The red line shows the pivot axis, or steering axis. When I lean or initiate a steering input, the trike leans around that axis. When the wind blows directly at the side of the fairing, you can sum up the force with one vector acting at the center of pressure (basically the center area of the fairing side view). The blue cross marks approximately where the center of pressure is for each version of the fairing. You will note that in the bottom photo, the wind would blow the nose of the fairing over causing the trike to turn in the direction of the wind. In the top photo, the wind would blow directly at the pivot axis and would not act on causing any steering at all.
And that's exactly what happens. And it works awesome! I went out for a ride in the wind today (winds 37 kph gusting 48 kph!!!!) and I could ride from a head wind and sharp turn to a sudden cross wind with no hands on the steering bar!! Plus I could loosen the cables off completely so that it was steering by leaning only and I had no problems. I could feel the wind blast, but it's effect on the fairing was very minimal. When the wind was a cornering head wind, there was a bit of wind induced steering, and when it was a cornering tail wind there was a bit of wind induced counter steering and sometimes when it was a direct cross wind, gusts would both cause a steer or a counter steer, but they were minimal and easy to counter.
Now, that's quite a lot of surface area in the back to add onto a fairing. I wouldn't be concerned about causing additional drag, but the extra surface area would create more surface friction - not sure how that would impact the overall aero efficiency of the fairing.
As far as weight goes, there would be some additional weight, but the next version of the fairing will be much lighter and stiffer than this one - so I'm not sure if that is a big concern.
Portability IS a concern. Currently I can stick this thing in my Element, bungie it into place and drive away. With the much longer tail, I probably wouldn't want to try that because the tail would be sticking way out into traffic.
Here are some quick renderings of what a final stretched fairing would look like:
Also today, I fixed my toe-out (a misalignment in the rear wheels). I found the next way was to use a laser level to plot a line on the floor a good 8 to 12 feet out. Then compare the widths of the endpoints of each line. I had to file down a very thin washer and place it on one of the flanges to remove the toe-out. The one thing I realized when measuring the wheel alignment is when you add weight to the seat, the rear wheel struts flex quite a bit more than I thought. Fortunately, the toe-in/toe-out doesn't change, but the camber does. I would like to add back that horizontal cross member, but the fairing rotates back there and I don't want to add any more aero drag. I getting Ben to do up some patterns and dimensions for a couple of strut supports that will run from the bottom of each flange to the upper cross bar - that should stiffen the rear end up quite a bit.
Hey - didn't the professor guy end up the hero?
Here are some various photos of todays craziness:
|For measuring toe-out, make sure you either sit on the bike or set weights on the seat. This DOES makes a difference!|
|A laser level worked better because it exaggerates the width difference between each wheel.|
|My dad helping out with the pink tail extension.|
|My mom - obviously proud of her little nerd boy.|
|The first version wasn't quite long enough. This one put the center of pressure at about exactly the pivot axis|
TCR2 (track) 2Do LIST:
1. Make a platform for the wind trainer (mini-rollers)2. Add front caliper brake
3. Mount first fairing and all the work required with that4. Make CF front wheel fairing
5. Make CF rear wheel discs
6. Make a new steering bar that rises up a bit higher - also takes up less room on the sides so fairing can be tighter
7. Adjustable seat height
8. Make fiberglass canopy top with acrylic bubble and tailbox
9. Paint this puppy!
10. Rear strut supports
TCR1 (cross country) 2Do LIST:
1 Add front derailleur
2 Run road, roll-over and watts tests for new suspension system3 Worm gear steer prototype (Waiting for final design and parts list from Ben)
|TOTAL distance on TCR1|
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