Here's my final impressions on the lightest kit. I'll start with positives, then negatives, and then a summary.
Positives:
Strong motor with good performance
Best performance to weight ratio available
Narrow Q-factors can be achieved
Flexible mounting positions/configurations
Negatives:
Very loud
Very conspicuous on bike, even with the shortest mounts
Subpar torque sensing
Complicated installation process with lots of tiny loose parts and requires soldering skills
Subpar cranks, bottom bracket, freewheel spider
The motor mounts are too oversized for the 6mm hex bolts included in the kit, resulting in needless slop.
The mounting brackets add 6mm of width to your bottom bracket shell, reducing options for standard bottom brackets
Good to know:
The motor comes locked from the factory, and will remain locked until you contact Bikee to get a special code that grants access.
The motor ships with a hard-coded speed governor set to 20mph that can only be bypassed buy purchasing an additional unlock code called "Race Button."
The throttle requires an additional unlock code to be purchased called "Superhero."
It would be good to have a bearing press to set up the bottom bracket included in the kit. You will receive a spindle, loose bearings, and spacers. You will need to press the bearings onto the spindle races without damaging them. I used a pipe and a rubber mallet.
You will receive a 3-pin MT30 plug for your battery to plug into the port on the non-drive side of the motor casing. You will need to tin and solder this to your battery cable. Bikee recommends 14 gauge wire for the battery plug. This is because it faces straight out into plastic cover that makes for a very tight fit. I used 12 gauge wire which did work, but resulted in the MT30 pins bending slighting under the pressure of the plastic cover.
The plug cover appears to be designed to collect dust and mud. It has large openings front and back that leave empty plug sockets exposed to the elements. The plug sockets might be potted/waterproof, but it is still a questionable design. The plugs are very small, and cleaning dirt out of them would be a pain. There is a very small drainage port at the base of the plug cover to prevent water from pooling, but it feels like a band-aid on a bad concept. This can be mitigated by sealing the openings up with sugru or similar after installation.
My chain guard had to be modified with a file to prevent the chain from catching on it when shifted into my 50T lowest gear of my cassette.
If you have a 68mm bottom bracket, the motor mounts will turn it into a 74mm bottom bracket. You might be able to fit some 73mm standard bottom brackets.
If you have a 73mm bottom bracket, the motor mounts will turn it into a 79mm bottom bracket. With an addition 2mm of spacers on each side, you should be able to fit a standard downhill 83mm bottom bracket.
The motor extends a great length out from your bottom bracket, giving gravity and impact forces a lot of leverage. I think Bikee should design a clever anti-sag mount that attaches to the front motor mount and braces it to the downtube. There is big ol' through hole sticking off the front of the motor casing. Use it!
You can mitigate the motor mounting slop with these:
An alternative freewheeling crankset confirmed by me to work very well with the Bikee Lightest motor kit is the HXR EasyShift:
HXR's Easy Shift crankset places a freewheel in your cranks, and blocks the wheel's freehub, allowing you to shift at any time when rolling or pedaling.
www.pinkbike.com
If you are lucky enough to have a 68mm bottom bracket, then chances are that the HXR crankset will fit, but...
The motor mounts from Bikee were not designed to fit external bearing cups. I modified mine on a mill to make more clearance, but most people likely won't have access to such equipment.
I will edit this post with more thoughts if when I get more time.