A technical discussion on the future TRX (or any ATV)

[Guy400]

Please don't laugh at my Photoshop skills and no, I'm not in the 3rd grade but I do have the artistic level of one:D At any rate, this is what happens when you've got the day off work and your mind begins to wonder. I thought about this several weeks ago and just now got around to doing the P/S work. One of the most important aspects of how well a quad handles (note: I didn't say THE most important) is where the center of gravity is. Lower is better in our sport. This got me wondering, why don't ATV powerplants rock the cylinder over much like an old BMW boxer engine? Obviously, valvetrain oiling passages would need modified but in doing this you're bring some of the weight from the engine closer to the bottom of the chassis. This also opens up a ton of room in the frame. As you can see by my green lines a new gas tank can be molded and lowered nearly 6 inches in the frame. Imagine the weight of 3 gallons of gas nearly 6 inches lower. Now that the gas tank has been lowered and is no longer partially under the front of the seat new area has been opened up for a taller rear shock mount. Raising this mount would allow for a new, taller long travel rear shock. Airbox would remain in the same place but with a longer intake tract. I didn't draw in the exhaust but that's not hard to picture in your head and skid plates (.190 aluminum) would be a factory-installed piece. If anyone else has any comments or any other thoughts please share them.

[Evan400ex]

I was just thinking about this. I know you want a low center of gravity but not too low. It will feel like your riding a 50. The ergo's would be terrible for larger/taller riders or even an average size rider. The bikes would end up just being way to small if you lowered the frame/gas tank 6 whole inches. The bikes today are perfect I think,...just low enough to where it still feels good and not overly cramped. Plus axle/a-arm upgrades fix any problems with the stability of the bike. Just my .02

[rtyfz450]

This is a good Idea but a nother thing to consider is weight transfer from front to rear if you moved all the cylinder wieght to the front the steering would be effected and you would not have as much room in the front for exhaust, the ports would have to be redesigned, the cooling system would have to be engineered, the oil, ect.....

[Guy400]

You wouldn't lower the frame at all, just set the gas tank farther down in between the upper rails. All the seat/handlebar/footpeg locations would remain where they are right now.

I also thought about the weight moving forward but I've really got no idea how much would move and would the trade off be beneficial at all? As the TRX head is now the exhaust port dumps out at an angle and I left enough room for the exhaust to exit at its stock location in the head but curl through the triangular brace area (similar to the exhaust on a 250R).

[rtyfz450]

I think moving the weight forward would have a negative effect on handling because they put the engine where it is because of it. the up and down design was adopted because it puts all the engine weight in one central location not spreading a greater area like a lay down would do. It puts the most amount of weight (the engine) in a unweight bias location ie not forward or back. THe opposed porshe (vw design) works great for a car because it is not moving the wight it is just keeping it lower not back or forward. the car that has the closest wieght distrobution to a quad is a formula 1 or indy car. it has a mid engine design driver forwar and handles far far superior to any other race car. Just my observations though:devil:

[rtyfz450]

by the way I think you did a great job illustrating your design idea. I was expecting something horific by the way you were settign it up.

[Chef]

With as well as we make rear shocks work with just new linkage, and revalving, etc, I would like to see them change the motor like you have in the picture, but then move the shock mount forward, making the top of the shock lower, and dropping the seat, tank, plastic, stem length, etc all down about 5 inches. Obviously, there would be some engineering involved for the rear suspension to clear everything, but, if they could do this the thing would handle flawlessly.

[2004TRX450R]

The biggest problem I see is where does the radiator go? The engine is so far foreward now there is no room for a radiator and if you try to move it up it is either going to be right out in front and vulnerable to rocks and stuff or to wide to fit between the frame rails unless you mount it on top like a Banshee. I do like your thinking though. It would take a lot of engineering and I'm sure that Honda put it like it is for a reason.

Donny,

5" lower would be a LOT lower. I know I'd be cramped on it. And you are as tall as I am so I would be you would be too. But if you are hanging off in the corners on a flat track it might be kinda cool!

[robman]

put the rad where the hood is like the raptor.

[2004TRX450R]

Originally posted by robman
put the rad where the hood is like the raptor.

Ya but then you'd have a yamaha:huh Also you then be moveing that weight back up wich is what you were trying to not do in the first place.

[biohazard1.2]

Originally posted by 2004TRX450R
Ya but then you'd have a yamaha:huh Also you then be moveing that weight back up wich is what you were trying to not do in the first place.

nice lil jab.

But, the weight of the radiator is much less than the offset caused by dropping the tank 6". So, moving the radiator up into a higher pos, while dropping the tank, with a boxer type cylinder, would GREATLY lower the CG. Go weigh some components for yourself.

Plus the higher you mount your radiator (up and away from the front wheels, will lessen the chance of a clogged (mud) or damaged (rocks) radiator during races.

The ergos could be worked out. Your idea and design might work real well, the only issue I would have is the width of the cylinder with this type of engine...would it stick out and cause shifting or footing issues? On the BMW bikes, it looks like there is some foot interference and you could probably not lean the bike over as far in the corners and, if you laid it down, you damage your cylinders (BMW)...but this would not be an issue on the quad (except for the footing/shifting prob)

nice post! gets the noggin a floggin

[2004TRX450R]

I think he is meaning move the cylender foreward not out to the side. I think it would look really funny with the radiator up top. There is lots of stuff in front of the rad in it's stock location to block dirt and rocks before it get's to the radiator where if you put it up top it is exposeing it to more of that stuff directly. Those beamers suck! There are footing issues with the head sticking out there and those things are HEAVY!!!!

[kwatts400]

Aren't the Beamers engines twins, a single cylender wouldn't be that wide at all.

[Honda]

Oh my god! LMAO right now! That picture dude!

Good idea though!

[Guy400]

My inference to the BMW engine was merely to illustrate how the cylinder is more parallel to the ground. In my design I would simply rock the cylinder forward, not to one side. I also think that dropping 3 gallons of gas and a cylinder/piston down is better weight distribution than worrying about moving an aluminum radiator with about 1/2 gallon of anti-freeze up. No matter where the radiator is at it is subject to rocks/mud and even in the position it is now serious trail riders buy screens for them.