Hub motor or motor and belt?

[pengyou]

I live in Shanghai and I want to buy an e-scooter that performs a little better than most.  I know there are laws re: speeds of these, but I plan on 90% of the riding out in the countryside.  I have seen the insides of the motors sold here and am not impressed, so I am thinking of buying a used scooter and upgrading it and putting quality parts in it.  I also want to have a scooter that stores the batteries in the floor instead of under the seat.  Finally, if I do the upgrades and fixings, I know that I will be able to fix it if something goes wrong out in the middle of nowhere.

I want the scooter to be able to cruise at 50 km/h, meaning I want to be able to ride it at 50kpm for as long as the batteries will hold out, not just hit 50 as a top speed for a few seconds.  It seems that it is easier (maybe even less expensive) to obtain this speed with the motor and belt vs. a hub motor?  All of the new scooters I have seen that do 50 are 60v or 72v.  It is my understand that to get a hub motor to go that fast you have to up the voltage.  To get a non hub motor to go that fast all I have to do is choose the right set of gears - assuming that it has the torque to handle it.  I have also heard that it is easier to change a flat tire with a chain than with a hub motor. I have read posts of people that have used 36v motors on a setup like this to get that kind of speed. 

I would appreciate any discussion you have on this topic.  

[Leslie]

I have a chain drive and I still have to remove the chain from the cog to change.

Speed volts and amps torque are all interchangeable to a degree.  The best match is how much amps your motor will draw.


But this is a deep and involved subject that evolves from the controller limitation and the impedance of the motors.

I still have much equipment to ascertain.  If one could give me the ohm resistance of the motor, dimensions, and materials we could figure out a good derating based upon the wire former stator fil, case ability to offset resistance via thermal output. And core width capability.  Ultra high voltages creates capacitance between the windings, polarizing the EM, losing inductance.  And the total resistance has a sweet spot for current.


Depending on you load you want a constant speed on  variable load so the motor must be rated 200% over the rating you use to achieve unity.  Even if you load you wheel 100% of its usage the wheel is still going to give you 100%.

If you use 2000 watts to do you rides at 50kph constant you need a motor can do 4000 watts,  In bicycle motors you can use an x5 and some   Im depending on the scooter weigh I'm sure the pie can do this but you would need to do 60v@ 35 amps and use a cycle analyst to slow it down. ..   

You would be lucky getting and internal controller happening you could use a dual pie 20" 18" or 16" for this.  Im not sure of the KPH on a 16"`18~Magic Pie is but they are still a big motor for slot size.

You will definitely get plenty of torque at 60.  When I compare my experiences with the HBS motors and look at the MP it looks like a motor that would preform efficiently at this voltage and at currents as high as 40 amps continuous as this is PMW,  inductive inrush usage is intelligent.

I fortunately have the internal controller.  I actually burnt a motor out dragging stuff around on a HBS.  Some of the trips we do have a lot of stop starts  The internal controller has a heat sensor in it.  And I lke to know the temperature isnt going to lose me another motor.  But with an external controller IMO the MagPie would more watts before the stator would be damaged.