In rec.bicycles.misc Chalo wrote:
: advantages a hydraulically driven bike could have over a chain driven
: bike, which might offset the drawbacks of what is almost certainly a
: heavier, lossier, and more expensive system than chain drive. So far

So besides the obvious issue of whether it can be made to work in
practice, there is the issue whether the efficiency can be
improved. Even with some serious advantages, I'd guess many
serious cyclists stay away from a system that loses them 5% or so
of efficiency.

: 2) Two-wheel drive, which this bike does not have

: This is another feature that some have tried to provide, while others
: wonder why. The benefits of four-wheel-drive in cars look similarly
: esoteric to me, yet many people opt to pay a premium for 4WD or AWD
: cars. If such a thing were available for bikes (and without glaring
: shortcomings), I wonder whether there would be any noteworthy handling
: benefits. I don't ride my bikes in the muck, but perhaps those who do
: would appreciate 2WD?

A drive on both rear wheels of a delta trike would be preferable.
With just one wheel driving they can have a tendency to turn one
way when going uphill. If you have two wheels driving the traction
is also better as one wheel slipping won't matter much then.

It would make drive design easier on trikes (and recumbents in
general). In an effort to eliminate the long chain, some people
currently create forward-driven designs. This introduces some
issues such as whether the chain needs to twist etc. The long
chain would be eliminated with a hydraulic system but also you
could probably easily make interesting designs such as a tadpole
trike with the drive in both of the front wheels. (Of course such
exist already but they might just become trivial.)

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Risto Varanka | http://www.helsinki.fi/~rvaranka/hpv/hpv.html
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