The trioendo is definitely part of the inspiration, but the suspension geometry is actually based much more on the Leanster and the Tilting Motorworks suspension. It will lean organically via counter steer just like the TMW or the Piaggio MP3. I’m not going to try to muscle it in and out of the lean as that’s both unnecessary and improbable given the end weight.

Glad to have your input!

http://www.aptera.com/

Will help with engineering.

I don’t know how much weight or size you’d save with the 400 compared to the 700, they are probably very similar in fact. But if you’re concerned with mpg at all, the 400 is definately the right choice. Even with hypermiling techniques, the eco-modding Burgman rider found that displacement was the limiting factor in improving mileage and so has bee downsizing his 400 engine to improve his efficiency.

To most of your other concerns (suspension, height, heat, etc.) I’d say to have a closer look at the Gurney Gator. seems he solved most of those problems by having the cylinder head between the driver’s legs and only the tail of the tranny sticking down under the seat. His seat height is only 18-20″ if I recall, and you really don’t want to get much lower than that for visibility reasons anyway. But he doesn’t have an enclosed cabin to deal with either, so… there are always compromises and what you have now looks as good as any.

Thing is, I don’t really look at length as an issue. It’s not any longer than a small car and that doesn’t bother me. Length will mean stability and given that the Monotracer is significantly longer than what I’ve spec’d here, I’m not worried at all. As for moving the engine up front, that has several issues. First, the front suspension box is literally under my feet and there’s no way to stick the motor into the middle of that somehow. So putting the engine in front of me means pushing the front suspension forward, which just makes the vehicle longer, so no real gain there. Second, if I were to put the motor more under me — say under my legs — then I may have shortened up, but I’ve also gotten taller. Height means more frontal area, which means less aerodynamic efficiency. Thirdly, having the engine essentially in the cockpit with me opens up a lot of issues (heat, exhaust leaks into the cabin, etc.) that I’d really just rather avoid. Heat especially. With the engine behind the cabin, I can build a thorough firewall insulating me from both heat and vapor.

Sorry for the long absence. I was on vacation and just got back. Always interesting to read through your well thought thru posts, and I admit I still have a few to go. So if these topics are covered later I apologize in advance. But here goes for now…

Possible solution to both your length and weight distribution issues to be seen in the Gurney Gator motorcycle (Google). Simply said… put the engine ahead of the driver, between his legs. Your weight moves forward, your length shortens because you can then move the swingarm pivot up, and you also gain the side benefit of getting to use a shaft drive engine if you want. Just put the bevel drive from the ATV driveshaft right at the swingarm pivot and put a sprocket on it so you still have a chain final drive.

And yeah… lots of 2 wheel drive atvs out there to be had, especially if you look at the sport quads which are almost all chain drive too.