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Hi Michael -
Nice work as always! The build looks great. About that truck...the torque generated by and required to turn those huge wheels must be enormous! Must have one heck of a leaf spring pack - if so, I wonder how the torque didn't wrack the leaf springs and axles off each other and/or the chassis!?
I understand the idea of the large diameter wheels, conceptually rolling over whatever may be in their path, but the strain on the suspension and driveline must be incredible...quite a truck and build! I can hear the u-joints whining from here!
Cheers
Nick
Greetings Nick
You are absolutely correct as to the "holy" wheels. That is why in the production vehicle the design was changed to solid wheels. In tests of the prototype, under strain, the engine torque rotated the centers right out of the large diameter perforrated wheels.
As to all that torque, the vehicle used the French concept of each wheel having its' own driveshaft. As far as I know there where no problems with the transmission of power to the wheels nor with the suspension system.
The vehicle's real problem was traction on hard pavement and on ice. They had snow cleats that could be bolted to the wheels but these were also made of steel so no help on pavement. If they had only made those cleats from rubber blocks they might have gotten somewhere.
Also the vehicle was too heavy for its' ground contact footprint and often sank into soft ground or dug a hole for itself.
Finally the mechanical brakes were horribly ineffective. Both the driver and co-driver had handbrake levers to apply extra muscle power and if all else failed there was a rear plow blade that could be dropped in case of emergency by the driver using a lever release in the cab. (Again, not much good on hard pavement.
I have been told a story (only once removed from the original author) of riding in one of these. The driver was stuck, not being able to get up a hard paved railroad embankment to the RR crossing. It took him several tries of backing further and further down the road and then trying to reach maximum speed in order to carry the vehicle up and over the RR crossing.