On Thu, 08 Sep 2005 16:41:54 GMT, Ed Earl Ross
wrote:

wrote:
because of the high proce of gas, would putting a motor on a bicycle be
practicle to get to work a few days a week? I live about 18 miles away
it is all highway with a wide berm for bicycles. I have a spare 5 horse
motor from an old tiller. Could I mount a bracket and put it above my
back wheel to drive the back wheel on my 10 speed mountain bike? Would
I be able to pedal it home if the engine failed? How would I rig a
clutch of some sort or would I even need it? Seems like an interesting
project.

How fast could you go with a 5 horse motor?

Some places the speed of unlicensed vehicles and motorized bicycles
is limited, check your local laws.

In most Canadian jurisdictions any powered bicycle that CAN move on
it's own, without pedaling, is considered a moped - limited to 50cc
engine displacement and, IIRC, 25MPH.
Anything else (bigger, faster, or no pedals) is a motorcycle. Both
need to be licenced. Both require a driver's licence to operate - a
moped can be driven on an automotive licence.

If you can design it that it can ONLY move if you are pedaling, it
becomes a motor assisted bicycle and MAY be allowed to run without a
licence. Virtually the only way this has been done is with electric
power.