Dear Canuck,

Please accept my sincere apology for my unfair assumption (and for
Harry's too) that everyone in the whole wide world is balanced on the
razor's edge of Aviation History.

Harry has paid his dues, however. Perhaps he will point us toward
some pictures.

The Wright's 'Flyer' is surprisingly up to date for anyone interested
in low-cost flight. Not a very good example, however, but given the
era it's surprising how much we can learn from their efforts.

The lubrication problem is common to all chain drives: you need to
get the lubricant down around the bar which supports the roller,
rather than on the roller itself. At one time Chain Drive was
considered the cat's meow when it came to trucks, cars and other
vehicles. And still is! (Ever seen the equipment used in a modern
lumber mill? They've got a kind of straddle-lifter that will make a
believer out of you when it comes to chain-driven vehicles.

Modern chains impregnate the bar (which probably has a more
appropriate name) with 'solid lubricant,' which I take to mean
Tungsten Disulfide or similar. Also note the amount of work a chain
absorbs, as compared to a belt drive.

There is also rope drives (!!) which I suggest we reserve for
Emergencies Only.

Mention 'chain drive' and almost everyone knows what you're talking
about, even though real chain, such as used for pulling a truck out of
the mud, is also used, typically in chain hoists and the like. But
most folks accept 'chain drive' as meaning the roller-chain common to
bicycles, motor cycles, AIRPLANES and so forth.

Motor cycle engines AND their chain drive, was fitted to a number of
gliders and sailplanes in the 1930's. There's no reason to think
we've seen the last of such conversions in the Twenty-First Century,
although we'll probably see a v-twin industrial engine replacing the
motorcycle engine. Why? Because it's blower driven cooling system
allows it to be submerged within the fuselage. Someone has even
suggested a twin-engine version, one pushing the other pulling, which
is pretty smart thinking, in that with both engines on-line you would
have plenty of thrust for take-off. Shutting down one of the engines
-- and allowing the prop to self-feather -- would allow you to cruise
on the remaining engine. Indeed, such a system may offer a
significant advantage with regard to price when compared to a larger
engine and a PSRU.

-R.S.Hoover