Thank you for your information. I’m really impressed reading the whole post and all the work done.
I just asked about the experience with 6s LiPo’s and the original control because I think that maintaining the original control is the safest option for the bike. I have some doubts about the behaviour and the % of the energy used at the cutof voltage around 20 V stated in previous pages.
In my opinion, replacing the NiMh battery by another LiPo battery of the same voltage does not affect the electric or mechanical transmission as this is only related with speed and torque, mechanically related with the opposite forces, likely aerodynamic force and the slope of the road.
I would like to give my point of view, that can be wrong due to the fact that I’m not still familiar with the insides of the transmissions and also due to my lack of knowledge about some electric questions described here. Please excuse me If something is wrong.
Looking in google, I found a description of the characteristics of DC motors (http://www.globe-motors.com/dc_motor.pdf
) and basically they are two rules:
• Curve Torque – Speed is defined by design of the DC motor. At the design stage, the constants of the motor are defined.
• Voltage determines Speed and torque will determine current. Different voltages define parallel curves increasing the speed at no load and also the torque at different speeds.
Based on this I think that applying a nominal of 36 V is “good” as the maximum speed is increased (50 km/h reported) and also the torque will be increased, really good for climbing hills, but the question is that I presume that the electric motor and the gearbox are not prepared for this. Usually it is stated that the Aprilia Enjoy is oversized but I doubt that the motor and gearbox will be, simply based on design rationality and in the evidences of the failures reported in this thread.
I have some experience in gearboxes as I have been working in a gearbox for WTG manufacturer company and even I can not see details from the pictures I agree with some posts saying that the origin of the damage is coming from bearings. It is unlikey that increasing a 50% of the nominal torque the gears get damaged with some hundreds of km. In my opinion a problem on the lubrication or in the preload of one bearing related with the increase load/speed and the increase of temperature associate could originate the failure.
The electric motor also would be checked, especially if it used at low speed. At high speed the refrigeration of the motor will be increased.
I think that using the original control and the speed and torque sensors working will help to maintain it safely. I could agree to replace the speed sensor by a throttle control as even if the motor works more time it does it along his original curve.