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Old 11-19-22, 03:53 PM
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kayakindude
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Watts human vs motor

Math question on electric assist. Riding a 75 pound fat tire Rad Rover for about 20 miles today. I noticed that on assist level one, regardless of which mechanical gear I was in the computer stated that the engine watts were between 60-80.

My question is how do I determine the average wattage it takes a human for that style bike to maintain around 15mph?

Wouldn't a higher mechanical gear lower the engine wattage, since one pedals harder on a higher gear?
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Old 11-19-22, 11:45 PM
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Doc_Wui
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That's how a controller works in curremt mode, putting a certain current to the motor in each assist level. Multiply by the voltage and it becomes watts. The controller doesn't know what gear you're using, but it does know the speed of the rear wheel. If there's a speed limiter in play, then it can shut off power.

My bike isn't a rad, but the controller delivers 100W in asisst level 1, and that's about 12 mph with easy pedalling. If I want to go 15 mph in level 1, the motor isn't going to add any more power if I pedal harder, It will still shoot out 100 watts, and the motor is probably spinning a little faster and helping a bit, while my feet add the necessary power to attain 15 mph.

I think what we would have to do is noit pedal and put the bike in cruise at 15 mph, and see what the controller puts out on its wattmeter to maintain 15 mph,

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Old 11-20-22, 02:11 AM
  #3  
Leisesturm
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Originally Posted by kayakindude
Math question on electric assist. Riding a 75 pound fat tire Rad Rover for about 20 miles today. I noticed that on assist level one, regardless of which mechanical gear I was in the computer stated that the engine watts were between 60-80.

My question is how do I determine the average wattage it takes a human for that style bike to maintain around 15mph?

Wouldn't a higher mechanical gear lower the engine wattage, since one pedals harder on a higher gear?
Have you ever tried to ride the bike without the motor on? My guess is that an ordinary rider would not be able to get that bike up to 15mph for more than a minute or two, if at all. It would be well over 100W of effort. Standard bikes are VASTLY easier to move, with less power necessary.
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