The question as to
which car engine to use for a trike might at first seem like asking how long is
a piece of string or a limp dick.
Having used modified Subaru diffs for a number of years with his motorcycle engined machines, Bob obviously had a bend towards the Japanese flat four motor, but it soon became apparent that another flat four was even more suitable.
"The Subaru engine is quieter and more powerful, but the rear torsion bar is just too heavy for a trike", explained Bob. "With the Volkswagon type 3 on the other hand, the complete rear end with independent suspension can simply be lifted out and the whole package is much more suitable in terms of weight and strength for trike application."
| *2003-04: We now offer the Subaru (E81-E82) motor matched to a VW gearbox as an option with our model 03/SA frame. We also supply the complete adapter kit to match the motor to the gearbox. |
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It can be seen that it isn't just a matter of lifting the engine from its car application, but the major components of the car's engine supporting mechanism also. Incidentally, one other benefit to the Volkswagon engine is that it doesn't require a radiator and plumbing for water cooling and as Bob so succinctly put it, "You could blow a hole in A VW engine with a shotgun and it'll still run - they're indestructible !" The need for independent rear suspension is not a point to be taken lightly either. In the old days, rigid rear ends gave trikes a none too glamorous image and Bob realised this very essential problem a long time ago. Needless to say, his motorcycle trikes have always had independent rear ends |
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Above. Single rear seat shown. |
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# Note. Most of the following has been changed on the new 2003-04 - 03/SA model frame. |
The Volkswagon type 3 torsion bar is no use by itself of course and mates to Bobs own steel tube chassis This is triangulated for strength and the front section is naturally a twin down tube copy of a basic motorcycle chassis. After all, a trike is a type of motorcycle and that's an argument Bob certainly won't enter into. The tubes in the chassis have a wall thickness of 2.5mm and the design is such that it mates directly to the Volkswagon torsion arm.
A beam across the VW gearbox adds strength and one of the design aims was to maintain access to the engine and gearbox. This has been achieved in that the entire power train can be unbolted as one unit within 15 minutes - once the bodywork has been removed of course.
THE PERSON IN THE BACK OF THIS SINGLE REAR SEAT VERSION IS SPOILT ROTTEN. THERE'S ROOM FOR HOT WATER BOTTLES - WHISKY BOTTLES - A FRIEND OR TWO !! AND THAT'S WITHOUT USING THE LUGGAGE COMPARTMENT.
A motorcyclist at heart, Bob has a head start over many other trike builders, as he understands the physics and geometry of motorcycle head angles and front suspension systems. There are no wildly stretched front forks on this Volkswagon trike, just a 32 degree head angle which is practical for everyday riding. (Note - you can have different variations of the theme as long as you understand the implications).
In the I980s, a variety of front
suspension alternatives appeared on numerous prototype motorcycles and several
of these have now made it into production (BMW's telelever for example). A number
have been tried by trike and sidecar builders the World over, especially centre
hub steering. According to Bob however, "Centre hub steering is very
involved and you've only got to be 1mm out for things to go horribly
wrong." As for the good old motorcycle telescopic front forks,
"Telescopic forks don't handle the same on a trike as they do on a
motorcycle and that can cause problems in itself".
Not surprisingly, Bob has devised his own front suspension set up which he describes as cantilever, offering significant ride quality and superb handling in all conditions. Consequently, the front forks on this Volkswagon trike are not forks in the traditional sense, but solid steel tubes with the cantilever system attached at the bottom.
The engine in this particular trike was lifted straight from a car and into its three wheeler role with no internal modifications.
JUST CRUISING ON THIS COMFORTABLE VW TRIKE.