Oregon commuter

[Grant-53]

Teflon based products help the water to bead but may eventually trap dirt. Trico used to have a hand crank wiper for the antique Jeeps but you could make something. Rambler used a vacuum system to run wipers. Maybe an air motor powered by exhaust pressure. A plastic container and a hand squeezed primer bulb could squirt washer solvent.

[Electictracer]

I Finally got started this last weekend! I bought $200 worth of steel to build the frame. I got much of the lower frame built. The bent frame parts require my square tubing bender dies that are being milled out. I have a lot of school work this semester, so things might go somewhat slow.

[low&slow]

good luck with your project, it looks like a lot of work

[Ken Fry]

Originally Posted by Electictracer

I Finally got started this last weekend! I bought $200 worth of steel to build the frame. I got much of the lower frame built. The bent frame parts require my square tubing bender dies that are being milled out. I have a lot of school work this semester, so things might go somewhat slow.

Hi Electictracer,

Here's a note I sent to Visionary regarding driving impressions, etc re my own enclosed motorcycle:

Hi Pete,

Looks like a pretty cool project! My main caution is that the vehicle should be vertical with respect to gravity when you come to a stop. The common alternative (perpendicular to the road surface) usually means that the bike is leaning when stopped (itself a little odd feeling) and so you must swerve to get the contact patches under the CG. This takes Monotracer drivers a while to learn, and even then, they still swerve and wobble, using up road space that might not be available.

I didn't spend a great deal of time on linkages before deciding to go with three wheels (just drive it like a car) but found that even with the outriggers deployable independently, it was hard to get the leverages right to permit both quick deployment and enough force to have good control if the vehicle started to lean too much. If the system were powered (as in power steering, with good force feedback) then this would not be an issue -- just have the outriggers reflect foot position.

My outriggers had casters for wheels, so that as they moved toward and away from centerline during balancing they did not create large drag, the way a forward facing wheel would. On the Ecomobile system, for example, tilting right and left (if possible) would cause a lot of tire scrub (which hydraulics could overcome, but human power could not).

You will need to be able to adapt to the situation in which there is a four inch deep pothole right where you need to have an outrigger (or in the path of an outrigger as you start to move).

I thought the idea of having feet come out the bottom was potentially unsafe, (as well as less than ideal aerodynamically) but it might be a simpler way to deal with balancing when stopped.

I'm an old roadracer, and familiar with countersteering, and I understand the physics of driving like a car with the outriggers down (steer right to go right) and driving like a motorcycle with the outriggers up (steer left to go right). But in actual operation of the vehicle, I found I could get out of synch. My seat was very low (6") off the ground, so roll inertia was low, and as a result the response time to control inputs was short (the roll rate was pretty high). Crashed once by getting out of synch -- kind of like the pilot induced oscillations that can happen with airplanes, especially during landings -- in my case right left right left right left boom.

I have not driven a Monotracer, but if you can find one, doing so would be helpful, I'd think.

That's about all I can think of right now, but if you have questions, please ask... and I'll try to respond more quickly. Actually a better address is ken@zingcars.com.

Regards,
Ken

[Ken Fry]

I used to do several types of motorcycle competition, but especially liked the very fast and the very slow: road racing and observed trials. For fun, I'd pick up my feet several (5-10) seconds before I would get underway at stop lights with my cafe racer. (A really good observed trials rider [which I was not] can balance a motionless bike forever.)

In an ordinary motorcycle, even at crawling speeds, you countersteer, to keep the contact patches under the CG. A certain amount of body english etc also helps. (At very low speeds, superimposed on the countersteering for balance is car steering for directional control. In trials riding, the bike is often leaning way over to the left while turning to the right -- all sorts of complicated stuff is possible.) But when I learned to ride a bicycle, someone told me, "if you are falling to the right, steer to the right" (which is the same notion as countersteering to pull a bike up out of a turn... In racing -- for some bikes -- this is the time when countersteering really becomes noticable, especially in switchbacks: the bike has gravity helping it to fall into a turn, but you have to work against gravity to get it back up.).

A lot of this stuff is incredibly subtle. A bike I rode in the 24 Hours of Nelson (for two years) was a 350 four cylinder Honda. I used to tell people that all I had to do was think about where I wanted to be and the bike would just go there. Because it was so easy to ride, we were not beaten to hell and back after an hour, so could still walk without falling over at rider changes. The people getting off the big bikes looked like zombies. In the second year with this little bike, (after a few mods to make it go a little faster than in the first year) we beat all the 500s 750s and open class bikes. The only bikes that could not pass us on the straights were "tricked out" Harley sportsters. But the Honda was so good in the corners that we were not working so hard, and could stay sharp... and as a result not fall off: while the big bikes were in the pits fixing crash damage we were out there ticking off the laps. I think you could ride that bike fast and never really perceive the need to countersteer: ounces of force on the bars was all that was required: a tiny shift of the shoulders would easily do the trick.

In my experience, almost all this (no-effort-required handling) goes out the window (wait no, it can't) in an enclosed bike. To bank the bike, you have to consciously countersteer. I rigged mine with a joysick, thinking that this would feel more natural. It did, sort of. At speed, it flew like an airplane: nudge the stick to the right to bank to the right, center the stick once the bank angle is established. (The stick was rigged so that pushing it to the right caused the wheel to turn to the left.)

But with the outriggers down, I'd have to use the stick in reverse. This felt really weird. If all roads and intersections were flat, then this would be a non-issue: you could have the outriggers up within the first foot of motion, provided it is clear ahead. But in very slow stop-and-go traffic, and when having to start out with the bike tilted, it was a significant issue.

My driveway slopes down at just under 20% to meet a road that slopes at 15% to the right. There is a dip between the drive and road surface, for drainage. At 5 mph with outriggers lifted on the drive, 15 feet before the road, this was pretty much OK. But at low speeds, I could easily be leaning a lot as a result of the dip combined with the effect of road slope. In my manual system, it took a lot of force on the pedal to keep from falling.

A couple things to notice in the Ecomobile video. One is Wagner thinks there is something wrong with a short wheel base. I think that is just plain wrong. Our 350 Honda was the best handling vehicle (land, air, sea) I have ever driven, and I've driven Ferraris, Loti, Porches, planes, sailboats, windsurfers, powerboats, etc. A well-sorted race bike is hard to beat for anyone with reflexes.

Another thing to notice in the videos is the jerky motion in turns and the amount of road used. You can see the countersteering happen in a way that you don't see in roadracing videos. It's notchy. I suspect that's because conscious effort is required, or maybe there is a tiny bit of friction (sticktion) in the steering. (In the shot where you see the wheel closeup, the motions are pretty large and abrupt as compared to typical motorcycle front wheel motions, which you can barely see at speed).

(All this is not intended to dis the Monotracer. It is a very good effort at a tough engineering problem.)

[Ken Fry]

Another thought.

A good way to visualize a space frame is with every joint replaced with a ball joint. A true (fully triangulated) space frame will maintain integrity under this condition (whereas a rectangular shape will just collapse -- lozenge). No tube should be subjected to a bending or cantilever load.

Torsional rigidity is critical. Even in well-engineered bikes, this does not always happen right. We moved to a 550 from our 350, and with suitable mods, it was faster. The stock 550 would wobble, however, and seemed to be perhaps sensitive to certain front tires. I reinforced the steering head area on ours and apparently cured the problem... although I'm not convinced that my gut level feel was actually the right thing to do -- I didn't use FEA or any of that kind of thing.

[drmiller100]

darts fly straight. They fly straight because most of the mass is well in front of most of the drag.

Vetter talks about this, and focuses on making sure this happens on his bikes with the big fairings.

The front wheel on a bike is pretty interesting. The caster is actually determined by the angle of the steering head.

There is caster caused by mechanical trail, and by steering head trail. I'm curious what the difference between the two in bike behaviour is - I'd guess steering head trail leads to high speed stability, and low speed wobble, and mechanical trail leads to low speed stability, but those are guesses.

[Ken Fry]

Originally Posted by drmiller100

The front wheel on a bike is pretty interesting. The caster is actually determined by the angle of the steering head.

By convention, rake is determined by steering head angle. Caster (usually called trail in motorcycles) can exist at any steering head angle. It is partly controlled by rake, but also controlled by offsets of the axle on the sliders, and the triple clamps.

You can have a bike with a vertical steering head but with as much trail as you want.

I think your summary of effects is pretty good, although the effects are so intertwined (and affected by other things, such as frame stability, masses that move with the handlebars, etc.) that it is hard to make generalizations.

Many bikes are effectively spaghetti... we use to straighten out front ends after a fall, by holding the front wheels between knees, and twisting the handlebars. When I was an inspection mechanic, I was tempted to flunk any chopper that came into the shop: they had nothing that could be called "handling," and nothing that could be called "brakes". One season, I rode a 250cc single in the 125cc GP class, and it handled perfectly, in my view. But when pulling into the pits once, I sat up, raised my hand to signal, and the bike went into tank slappers. (This with a pretty stiff frame, very stiff forks, and geometry that was very ordinary for a road racing bike.) The front brake was large relative to the bike's weight, so I suspect this had an influence.

As far as I know, it's all magic.

Tony Foale has done some cool experiments with rake and trail... and lived to tell about it. (Darn frames... this link came from the article itself, but only gives the base address. If you look under "articles" you'll find the rake and trail one, where he describes modifying a BMW in pretty dramatic ways.)

[drmiller100]

thanks for the links.

there is something called precession. I have been wondering if the angle of the steering head, and precession, keep the bike "stable". but the experiments you posted sure make sense in showing it does not matter.

Something worth reading -
Bicycle and motorcycle dynamics - Wikipedia, the free encyclopedia
the section on Wobble or Shimmy

I'm old and fat, and was more of a snowmobiler then a motorcycler. Did your wobbles start when you let go of the handlebars because you were not hanging onto the handlebars any longer?

Perhaps there is a harmonic with the flex of the front steering system and the mass of the system - change the mass, and things quit wanting to "vibrate".

[Electictracer]

Great information, although I cannot claim I fully understand all of it. Thankfully, sporty performance is not a concern for this project; I have a bike that handles amazingly for that purpose. I do need it to be safe and controllable. I have decided not to change any of the existing geometry of the steering; I am just lengthening the wheel base considerably. I know this will have a negative effect on steering responsiveness. Again I don’t plan on racing and its base is similar to the monotracers.
Ken, I’m very interested in your outriggers you mentioned. You said they were manually powered and fell with gravity? How, or did they, lock in place. My plan is to use two double acting pneumatic cylinders (one for each outrigger) to retract the “training wheels.” With the loss of air pressure, springs will drive the outriggers down into the ground. Moments after they are down, my valves will close up both sides of the cylinder. My thoughts are this will act as a shock absorber and basically make it impossible for the vehicle lean over too much.
If anyone has any impute on this I would greatly appreciate it. I have ordered some of the materials to build this system, but am kind of waiting so I can consider it further. Thank you