RR8 Rolling Resistance
2010-05-18
We measured the rolling resistance of RR8 on a smooth and level floor inside the schools DT department. The test was done with the car including batteries and a driver. The car was pulled behind a model tank with a piece of string and two force meters in parallel (we didn't have one of the right amount and so used a 10N and 5N one). The motor was driven by the chain drive and we were using Schwalbe Durano tyres at 100PSI.
The all up weight was: 53Kg(Car) + 40Kg(Bats) + 48.6Kg(Driver)
The average force was: 8.5N. Cr is about: 0.006
With the rear tyres replaced with Schwalbe Kojak's at 100PSI:
The average force was: 10N. Cr is about: 0.007
With a greater all up weight and the Kojak tyres:
The all up weight was: 53Kg(Car) + 40Kg(Bats) + 79Kg(Driver)
The average force was 12N: Cr is about: 0.007
With the greater all up weight and the Kojak tyres at 110PSI:
The average force was 11N: Cr is about: 0.0065
Note: There was quite a variation in readings as it was difficult to keep the car moving at a steady pace. These were the average of about 8 runs in each direction.
Driver Weights
Driver | Weight |
---|---|
Tom | 48.6Kg |
Gareth | 54.6Kg |
Dan | 62.2Kg |
Ben | |
James | |
Liam | |
Dawn | 41Kg |
Stephanie | 45.4Kg |