Using hydraulics for motorcycle powered vehicle...

[Baby Grand]

You need a good volume of oil in the reservoir to clear air out of the scavenged oil before you run it through the pump again. That volume of oil is essentially dead weight, plus you'll need to baffle the tank so it won't slosh from side to side in the corners - which I would think you'd want to avoid with a 3 wheeler.

I think the advice the others have given about using a gear or chain drive would be a lot less headache.

 

[oldnslo]

Unless you want to move slowly with lots of low end torque and infinite speed control hydraulics are not the answer to this problem. HST by design are heat generators. The charge pump system is pure heat and lost energy a majority of the time. Your MC engine probably develops its HP at 7,000- 8,000 RPM or higher. I don't know of any HST that will run at that RPM.

Like others have stated gears and or chain are your best option.

Honda Goldwing trikes and BMW K-LT trikes all have reverse. I believe they run off of the starter motor and are intended for short distance light duty use.

Roy

 

[partial2polo]

Thanks a ton to all of you for your feedback and response. Looks like I have some work ahead to figure out how best to incorporate a drive shaft to a compatible rear wheel assembly (like a Moto Guzzi or Goldwing). Thanks guys.

 

[jimgerken]

Why drive the rear wheel at all? If its a three wheeler, drive the front end. Existing technology (any small front wheel drive car), light weight and efficient, better traction, better handling, more tire to hold the power, and more advantages. Just let the rear wheel tag along to hold up the trunk.
XR3 Hybrid Personal Transit Vehicle: A 125 mpg Plug-In Hybrid Three Wheeler You Build From Plans

 

[Baby Grand]

Why drive the rear wheel at all? If its a three wheeler, drive the front end. Existing technology (any small front wheel drive car), light weight and efficient, better traction, better handling, more tire to hold the power, and more advantages. Just let the rear wheel tag along to hold up the trunk.
XR3 Hybrid Personal Transit Vehicle: A 125 mpg Plug-In Hybrid Three Wheeler You Build From Plans

It does sound reasonable if you can get the CV joints & diff in a small enough size to provide the swing you need while fitting inside the front track at a reasonable weight. However, both Morgan and Messerschmidt seem to have gone the OP's way (note the reverse problem solution):

Engine and transmissionThe KR200 ran on a 191 cc (11.7 cu in) Fichtel & Sachs air-cooled single cylinder two-stroke engine positioned in front of the rear wheel,[6] just behind the passenger's seat.[3] The engine had two sets of contact breaker points and, to reverse, the engine was stopped and then restarted, going backwards. This was effected by pushing the key further in the ignition switch than normal, whether intentionally or not. One result of this was that the KR200's sequential, positive-stop transmission provided the car with the same four gear ratios available in reverse as in forward movement

Messerschmitt KR200 - Wikipedia, the free encyclopedia

 

[DAY]

I spent a year (1956) in Tokyo, and three wheel pickups were ubiquitous, delivering everything from lumber to lunchtime boxes of take-out noodles.
The front half was a 2 cylinder motorcycle, single seat, with a windshield and top, no sides. back end was a box, about 4x4, with one foot sides and a tailgate. I don't know about reverse; I (Navy brat, HS student) was more interested in my neighbor's Ariel Square Four!

 

[partial2polo]

I am familiar with the Morgan. I was hoping for a better reverse solution without spending $1500+ on a custom gearbox. There are options for using a high torque electric motor for reverse (ala the Honda Goldwing which uses the starter). Front wheel drive is also an option I have considered, but was trying to stay from an auto engine and all the associated emission equipment, fuel injection and other gear. I am going for a vintage look, like a Morgan, but with better driveability and performance. Ideally I will figure out an optimal method to hang a bike engine on the front and keep it simple. Thanks guys.

 

[BHD]

use the regular transmission for forward, and if you want or need reverse, you could either use a electric starter type motor, or use a power steering pump and a small hydraulic motor that either has a one way clutch or a advancing dog similar to a starter drive to do reverse with. and attach it to the rear axle, most likely you will not be backing any real distance,

 

[smiley]

you might look at the older Polaris 2wd four wheelers. They have a separate rugged looking chain drive forward reverse only transmission.