Forget The CB750's, CB900C Trike Ideas!

[Angel And The Wolf]

Think I'd like to attach the VW front axle unit to a home made narrowed three wheel version of an Atom exoframe. I want to sit centered, so the steering column will have to have a three gear set to transfer the input to the left to line up with the steering box on the VW unit.

[Angel And The Wolf]

Originally Posted by Angel And The Wolf

Think I'd like to attach the VW front axle unit to a home made narrowed three wheel version of an Atom exoframe.

Of course, with a lighter, far less powerful engine, my tube frame could be smaller diameter, or lighter gauge tubing.

Originally Posted by Angel And The Wolf

I want to sit centered, so the steering column will have to have a three gear set to transfer the input to the left to line up with the steering box on the VW unit.

This solution would also allow me to custom tune the steering ratio for quicker
(less turns lock-to-lock, preferably 1/2 turn lock-to-lock, if the front end is light enough), and using non-circular gears, I could limit the quicker steering progressively towards left lock and right lock, without it being so sensitive to minor input at dead center.

[Angel And The Wolf]

I could start with a VW floorpan and front axle, narrow the floorpan to one person wide, and attach the bike to the rear. There are two options that would preserve the steering geometry. One puts the bike forward of the VW's original rear axle, and the other is less conventional, putting the bike's front forks where the VW's original rear axle was, (probably have to re-orient the fork angle to 0 degrees vertical) and allowing the bike to move left or right controlled by the front wheel steering angle.

[Angel And The Wolf]

Yeah, the three wheel steering extended version is probably a bad idea. Better to go with the bike forward design with the bike's rear wheel centered on the VW's original rear axle. More places to secure the bike to the floorpan, and my wife would probably make me use the Prius to take her places, anyway. A skin would fit over that better.

[cRiPpLe_rOoStEr]

Originally Posted by Angel And The Wolf

I want to sit centered, so the steering column will have to have a three gear set to transfer the input to the left to line up with the steering box on the VW unit.

Couldn't you just move the steering box more centered, even if you would need to make custom control arms? My dad has already seen a homebuilt cargo trike with a centrally-mounted VW steering box.

[Angel And The Wolf]

There are aftermarket VW front ends. Your dad may have seen one of those. Nonetheless, putting gears between the upper and lower steering shaft gives me the oportunity to change how far the wheels move with a turn of the steering wheel, and since the trike is lighter, I could use quicker steering.

[Grinder74]

Make sure you get the CG right. Problem with attaching a bike to a car chassis is it can get loooong. If you go single seat, look into offsetting the engine beside the rider. That could simply shifting, just operate the shifter on the engine with your right hand,
Maybe even add the clutch to an extension off the shifter. Clutch and shift with one hand.

[Angel And The Wolf]

Yes, it would be as long as a VW Beetle. The bike's rear tire needs to be centered between where the VW's rear tires would have been to preserve the Ackermann steering geometry.
The shifting would be done with paddles on the steering wheel. One paddle for up/down shifts of the five speed, the other for high/low shift of the two speed.

[cRiPpLe_rOoStEr]

Originally Posted by Angel And The Wolf

There are aftermarket VW front ends. Your dad may have seen one of those.

I'm sure it wasn't an aftermarket one, even though it had been modded.

Nonetheless, putting gears between the upper and lower steering shaft gives me the oportunity to change how far the wheels move with a turn of the steering wheel, and since the trike is lighter, I could use quicker steering.

Now that makes sense.

[Grinder74]

I just meant the engine, not the rear wheel and suspension. Paddle shift would add some cool factor.