Possible to make an Ebike go 75+ mph?

Cody196

Member
Hello does anyone know how I could manage to get an ebike to go 85 mph? What amps, motor, and voltage would i need to achieve this goal?
 

Cameron Newland

Well-Known Member
Hello does anyone know how I could manage to get an ebike to go 85 mph? What amps, motor, and voltage would i need to achieve this goal?
You'll want a 100V system with a 100A controller. You'll need some seriously thick wiring to handle that kind of discharge current, and your battery will either have to be LiPo (prone to fires, hard to charge properly) or will have to be composed of 20A/25A/30A 18650 cells, which are expensive and tend to have less energy density than other cells.

The easiest way to go about it would be to contact Kinaye Motorsports in Seattle. They'll set you up with a MXUS (3000W-rated) direct-drive hub motor, a beefy controller, and a battery that can handle 6000W+ peak output. That should get you close. Their bikes will definitely hit 40MPH and perhaps 50MPH. If you want to go faster than that, you might have a pay a bit more.

Another good motor option would be the QS205 hub motor laced into a 17" moped wheel. I've been told that some QS motors can handle 10000+W.

Any ebike capable of hitting 75MPH would probably weigh at least 85 lbs, if not more.
 

dm nelson

Active Member
I think my honda fit has hit 75. I've hit 30 with the radrover going downhill. I figure, why hurry, life's short?
 

JohnT

Active Member
Just about anything possible with enough money, but it won't be safe nor legal. Bicycle frames and components aren't made to handle the stresses of that speed. I recommend converting a motorcycle.
 

ROJA

Active Member
Just as a thought experiment, I tried http://www.bikecalculator.com/

for a 70 kg (154 lb) rider on a 27 kg (60 lb) bike, this will give you a sense of how hard this would be:

Power (motor plus legs) --> Speed kph / Speed mph

200W --> 31 kph / 19.3 mph
300W --> 36.2 / 22.5 (100W adds 3.2 mph)
400W --> 40.3 / 25.0 (+2.5 mph)
500W --> 43.8 / 27.2 (+2.2 mph)
600W --> 46.8 / 29.1 (+1.9 mph)
700W --> 49.5 / 30.7 (+1.6 mph)
800W --> 52.0 / 32.3 (+1.6 mph)
900W --> 54.2 / 33.7 (+1.4 mph)
1,000W --> 56.3 / 35.0 (+1.3 mph)
*****
5,000W --> 98.2 / 61.0 mph
*****
10,000W --> 124.2 / 77.1 mph
*****

150cc vespa = 8650 W (11.6 hp) (less at the rear wheel)
Honda CBR300 = 20,730W (27.8 hp) (measured at the rear wheel)