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View Full Version : Question from a wannabe builder



KoolKat
05-02-2011, 08:44 PM
"How fast can it go and for how long?"

Odd Man Out
05-02-2011, 10:28 PM
I would say that the designer would be the best person to respond on this one...

Radical Brad
05-03-2011, 01:32 PM
So many variables, but let me do my best...

If you use exactly the same batteries and hubmotor I did, then you can expect to go about 30 miles per hour for about an hour before the batteries start to fade. This assumes no pedaling and terrain with only slight hills and not much headwind. Most hubmotors will top you out at about 25 miles per hour, but mine is running from 48 volts, which is 12 volts over the recommended rating.

Here is where things change....

Alter the wheel diameter and you go faster with a larger wheel. Use a brushed motor and you lose some efficiency. Hit a good headwind and you lose about 25% of your range. Add a couple of really steep hills into your trip and you will have less than half the range. Spend the big $$$ on lithium batteries of the same Ah rating, and you can more than triple your range. Add human power to the mix, and you can probably ride all day long, using the motor to make it seem effortless.

The speed and range ratings on hubmotors do seem fairly accurate from the distributors, so they are a good guide as well.

Brad