A question that interests me: which is more feasible:-
1) making a high-torque/low-speed motor higher speed by increasing the voltage available
2) making a high-speed/low-torque motor more torquey by increasing the amps available
Any thoughts?
This question stems from the fact that the two factories that produce the XM-3500 and the RMartin bike each have opted for a different class of motor. The XM comes with a high torque but low top speed. The RMartin comes with less torque but more top speed.
Naturally, customers want both - lots of acceleration and lots of top speed. So, to reach "EV nirvana" is it better to start with an EFun or an ERider?
Or, is it better to sacrifice the simplicity of the hub motor for the gearing opportunities provided by a non-hub motor setup?
I belive that is the formula. More volts= more speed, and more amps= more torque.
Most modders are upping both, no suprise.
Be the pack leader.
36 volt sla schwinn beach cruiser
36 volt lifepo4 mongoose mtb
24 volt sla + nicad EV Global
John,
This is a very interesting question.
FWIW I think using a higher speed motor and changing the torque by lowering the gear ratio is the best way to proceed. I have several e-bikes which use small motors through gears and I have ridden several hub motor bikes. I have noticed the Hub motor is much simpler but does not have the acceleration I am accustom to from the geared motors. I had the opportunity to test my 400 watt geared motor with a 400 watt Hub motor. The Hub motor had better overall control at cursing speeds but lacked the acceleration of the geared motor. Both bikes had a top speed of 22 to 23 MPH on a full charge. The hub motor also lacked the range of the geared motor by almost 3 miles. The current draw during acceleration was also very different for both bikes which may be one reason for the loss of range. I also believe this was due to the difference of the controllers. My geared motor would draw a max of 25 amps while the hub motor was drawing 35 amps. Even with the increased amperage the Hub motor could not keep pace with the geared motor during acceleration.
Grandpa Chas S.
ROTFL - that's a great typo! Do the curse words get worse as the speed increases? Or is it the other way around "get out of my way you !@#$%QA slow coach!"
:lol:
John H. Founder of Current Motor Company - opinions on this site belong to me; not to my employer
Remember: " 'lectric for local. diesel for distance" - JTH, Amp Bros || "No Gas.