Article: Stephen Britt talks to Pedelecs about his electric pedal invention
- Thread starter rsscott
- Start date
Stephen estimated 100W power assistance.
Assume that each down stroke will take about 1 second (30 rpm).
Thus:
Torque = (100 W / 2 x pi)/1s = 15.8Nm/s
Assume that the radius of the pedal is 0.06m, the upward force exerted on the pushing foot will be:
F = 15.8kgf/(0.06m/sin(x)) with x being the angle of the pedal from the vertical, sin(x)=1, F= 264kgf
I reckon the average output would be nearer to 10W than 100W.
Assume that each down stroke will take about 1 second (30 rpm).
Thus:
Torque = (100 W / 2 x pi)/1s = 15.8Nm/s
Assume that the radius of the pedal is 0.06m, the upward force exerted on the pushing foot will be:
F = 15.8kgf/(0.06m/sin(x)) with x being the angle of the pedal from the vertical, sin(x)=1, F= 264kgf
I reckon the average output would be nearer to 10W than 100W.
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Hi Trex,
I measure the power output using a Tacx t1970 for tuning and testing and a Power Tap hub and Garmin for road use. The same route is ridden, with and without the system switched on.
All the best,
Stephen.
I measure the power output using a Tacx t1970 for tuning and testing and a Power Tap hub and Garmin for road use. The same route is ridden, with and without the system switched on.
All the best,
Stephen.
The 50wH of battery is exhausted in half an hour. To do that you need to be buring 100w for half an hour. At 10w I would get 5 hours use.
Idea for a test:
Equip a bike with your pedals and put it on its stand.
Connect the rear wheel to a dynamo.
Cycle with the assistance of your pedals and as little leg work as possible.
Collect the data on the dynamo output.
Switch off the pedals. Cycle normally.
Collect the data on the dynamo output.
Compare the two outputs.
An average human can produce about 200W cycling.
Equip a bike with your pedals and put it on its stand.
Connect the rear wheel to a dynamo.
Cycle with the assistance of your pedals and as little leg work as possible.
Collect the data on the dynamo output.
Switch off the pedals. Cycle normally.
Collect the data on the dynamo output.
Compare the two outputs.
An average human can produce about 200W cycling.
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What a wonderful rescue device for off-shore pedalos!
Tandems (4 pedals) and triplets (6) will soon be whizzing along A roads, scaring plodding motorists ...
Tandems (4 pedals) and triplets (6) will soon be whizzing along A roads, scaring plodding motorists ...
I cannot understand how these will work. If you switch on without anything on the pedal, it will turn backwards. If you put your foot on it to stop it turning, you will have to press with a force equal to the power it is giving out to make it turn backwards, so the pedal and crank stay stationary, even though you are pushing forwards with 100 watts and the pedal is pushing backwards with 100 watts.