On Mon, 18 Oct 2010 20:05:33 +0000, Jules Richardson wrote:
There must be a fine balance I think between the belt being slack enough
not to cause the reversing mechanism to bind, but yet still tight enough
when the clutch is released to allow drive without slipping.

Follow-up thought - I think I'm wrong there. I think that the clutch
adjustment must dictate *only* by how much the conical clutch moves
toward the engine (and hence how slack the belt goes).

Traveling in the "other direction", the clutch rod doesn't play a part -
at some point, the clutch pedal fully engages the clutch and the
"currently selected gear" linkage takes over, and it's this which says
how far the conical clutch is able to move away from the engine (the
distance from the engine, with the belt "biting", being proportional to
the gear ratio due to the way that the conical transmission works)

It's dark and cold and full o' bears outside now, but I'll have to have a
look tomorrow and see if that seems sensible :-) In my head it does,
though. The upshot of all that is that I should be able to adjust the
clutch rod as much as I want as a test - the worst that can happen is
that I make the belt too slack and it comes off one of the pulleys, but
it shouldn't disturb the gearing or belt tension.

(Ingenious little transmissions, these - amazing they work at all given
the harsh environment that they're subjected to)

cheers

Jules