I would like to convert my Votec bike, which is currently powered by an MXUS 3k hub, to a middrive.
The main reason i want to give away the hub is the poor handling at uneven roads. The whole bike is shaking like hell if the road is bumpy and uneven. There are no issues with the fork or the damper, the only thing which might be not optimal in terms of suspension physics is the low weight of the frame.
It is about 25kg (frame with all parts + battery) fighting against 13-14kg of unsprung mass (motor + rear wheel). Aside from my personal experience this is also in theory anything but optimal.
When i am driving over potholes it comes through quite hard and rough, and the quick road irregularities are not filtered well. the wheel simply cannot follow the surface quick which leads to a very uncomfortable ride than.
My plan is to install the motor on a bracket which will be welded to the swingarm. The problem is there is limited space, so motors like the BigBlock's won't fit, and because i do not like to power it over the chainring on the pedals, units like BBSHD or Lightningrods are no option.
I am thinking of going with a belt drive with about 7:1 reduction (or a bit more even). Belt drive because of the possibility for regen
If the diameter of the motor is below 110mm, it should fit without touching the frame if the damper is full compressed, so i started to search for such motors.
- NeuMotors 8057/75
https://neumotors.cartloom.com/storefro ... uct/126891
It is a 16P motor and somewhere stands "18S16p" so i think it has 18 teeth (but not confirmed).
as the name says the size is 80mm dia x 57mm wide with a kV of 75 (optimal for my 20s battery).
the rpm range is 4000-8000
Case Length 92mm
Stator diameter 80mm
Stator length 57mm
Shaft Diameter 14mm
Mounting 6x 56xM6mm
Internal Resistance: 24mOhm
Idle Current: 1.6A @ 10V
Limit (15s): 20'000W
poles: 16 (8 pairs)
At the moment the price is 399USD for the motor and about 60USD for the necessary front mount axle:
http://www.leomotion.com/shop/USER_ARTI ... el_ID=8566
the 8057 is on the far right:
things to find out for the NeuMotor:
- how is the cogging of 18S16p design (or torque ripple?)?
- would it be possible to install hall sensors?