FrizzleFried
Well-Known Member
Being there isn't anything actually... special... going on inside the gearbox for these things... am I safe to assume that if I'm pulling 20mph or so at 4000RPM it's going to take 8000 RPM to get up to 40mph?
Dumb Math Question
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Nickt919
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Tire Size, RPM, Speed, and Differential Ratio Calculator
Describes the process for converting a gasoline powered car to electric power
www.advanced-ev.com
Chainlube
Well-Known Member
This one is easier to use, use the engine output gear and the clutch gear in the first two sizes.
electricscooterparts.com
Motor and Gear Ratio Guide and Calculator for Vehicles with a Jackshaft - ElectricScooterParts.com
Electric scooter with jackshaft motor and gear ratio guide with gear ratio calculator.
electricscooterparts.com
Chainlube
Well-Known Member
I just calculated 42mph with a 40 tooth wheel sprocket.
It's mechanical relationship, and barring a few variables, your thinking is pretty much spot on. In rough terms for every 200 rpm of fhe engine you see 1mph in speed.
If you want to check the theory for yourself compare your speeds and rpm. If the above is accurate you should see 10mph at 2000rpm, and 15mph at 3000rpm.
Sidewinder Jerry
Well-Known Member
Sidewinder speed formula:
(RPM × Wheel Diameter × π)÷(1056 × Total Reduction) = MPH.
What rear sprocket are you using? What size tires are you using?
(RPM × Wheel Diameter × π)÷(1056 × Total Reduction) = MPH.
What rear sprocket are you using? What size tires are you using?
Nickt919
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If his numbers are close and has 26” wheels I calculated a 38T
FrizzleFried
Well-Known Member
36T ... 26x2.125
Sidewinder Jerry
Well-Known Member
4000 rpm nets you almost 21 mph. You'll need 7633 rpm to do 40 mph.
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