counter shaft

[Michael A Perry <mperry@efn.org>]

My little car has an Advance DC K91-4003 motor, driving a Gates Polychain into a
countershaft @ about 2:1 ratio, then stepped down another 4:1 to the rear wheel.
This is a good design, as it removes drive loads from the motor, but I think I'm
losing a lot of power to the shaft. This is similar to the "tool grade" shafts
we used to use to build grinders, using old washing machine motors. Lots of
ruggedness, but probably not efficient.

The countershaft has a pulley at each end, supported by 3 bearings.  After a 5
mile drive, I noticed all 3 bearings are warm to the touch (about the same temp
as the motor). The bearings are sealed on the sides, with grease zerks for
adding more grease. I (needlessly) greased the bearings with low friction lube.
While the entire system has very little wear, it has set, but I don't notice any
"rough spots" when turning the countershaft, so I don't think the bearings have
seized. There is significant drag in the drive train, as when I spin the tire,
it stops almost immediately.  I'll check this weekend to make sure the shaft
isn't binding (it's mounted to 3 different support members) but I'm mainly
looking for lower friction bearings.

Removing the countershaft would place considerable load on the motor, as I'd
have to increase the main drive belt length by 8+" (after remounting the motor,
reversing drive power, building new mounts, etc).

As a side, I also loosened the rear wheel by 1 1/2 turn of the adjuster bolts.
It's mounted similar to the rear wheel on a motorcycle.  This loosening of the
drive belt gained me nearly 5MPH on top speed, but after driving 14 miles, it
has "tightened" again.  With the belt on a counter shaft, this extra tension
isn't lessing my motor's bearing life.