Transmission is by single V-belt ( 'A" section)
The motor is mounted on the chassis, its centreline passes through the swingarm pivots so that the belt's tension does not vary with up and down wheel movements. The drive ratio is easily changed for different conditions.
A small set of motor pulleys provides for the complete terrain range
from smooth level bitumen to undulating paddock bashing.
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The table below shows important relationships in deciding motor pulley size.
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pulley | ratio | *speed | *current |
72mm | 5.125:1 | 47 Km/h | 15-20 Amps |
85mm | 4.33:1 | 52 Km/h | 20-30 Amps |
98mm | 3.75:1 | 62 Km/h | 30-40 Amps |
The main advantages I see in belt drives are:
Electric motors can very quickly draw dangerously high current and burn out when stalled.
I tension my belt so that it will slip at 35 Amps with handbrake fully on,
this still gives ample traction in all normal situations
and if I hoon with too much spirit I will not damage the motor or wiring.
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