Help with : HPM5KW Golden motor + VEC 300

[Luis_agl]

Hello,

Anyone can help me ? : ))

Attached the picture of the Motorcycle
I`m using : HPM5KW Golden motor + VEC 300
The battery its 48v battery with max continuous discharge current no less than 120A.
On the picture you can see the the crown little one is 60mm and big one is 220mm.
But in my first test, the motorcycle have almost 0 torque, and max speed was about 10 to 15 km/h.
Do you think this problem can be electronic problem ? Or I should make change on the transmission ?
Thanks a lot ! 

[Bikemad]

Hi Luis andto the forum.

Your gear current ratio using a 13 tooth front sprocket and a 46 tooth rear sprocket will produce a gear reduction of ~3.54:1.

The following bike is fitted with the same 5kW motor, but it has a two stage gear reduction which produces a combined gear reduction of ~12.9:1.



Check out this post for more details.

The above bike is low geared for trials use, so it only has a top speed of 34mph, but your bike is currently geared for a top speed of ~125mph at the same motor rpm (assuming it has a similar diameter rear tyre). 

Your current gearing is probably going to strain the motor excessively and force it to draw high current which the controller might not be able to deliver at low rpm.

Having said that, I would still expect it to go a lot faster than 10 to 15 km/h once it gets moving on the level.

It might be restricted by the settings in the controller, but without knowing what they are, it is difficult to say why it is currently quite so slow.

Ultimately, it really needs to be much lower geared to make it useable on hills etc.

Alan
 

[Luis_agl]

Thanks a lot for the information !
I`m working on the gear reduction, will be around 1:2,20
Some pictures attached, for others customer see if have any questions !
Made by myself with CNC machines.