Huge wrote:
Mortimer wrote:

I remember in the early 80s getting lifts from a guy with a Volvo that had
Daf CVT. It seemed to have a very sensitive change-down and very late
change-up:

CVTs do not change up or down. Which bit of "continuous" is it that has passed
you by?

They change up and down - just not in discrete steps.

I drove a Volvo 66 for a few months many years ago, and got used to its
peculiarities. When the transmission was correctly setup you could
usually choose when it changed up by delicate use of the throttle - just
backing off the power briefly would start it winding its way up the
range so you maintained speed but lost revs. You also got some natural
variation in drive ratio in response to changing load - more load pulled
the belts deeper into the vee shaped pulleys reducing the effective
diameter of the pulley. There was no "kickdown" as such, but
accelerating hard in a higher ratio would cause the box to drop the
gearing a bit (by widening the vee gap in the pulley) in addition to
that gained from the loading effect described above.

--
Cheers,

John.

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