Thanks Danny. I'll be working on a mounting plate for the scooter motor today. The photo shows how compact the brushless motors are. There are 8 threaded mounting holes on the face of their case and locating the precise position of each of these holes on an aluminum plate is my project this morning. This completed plate and motor will then be bolted to the V-twin motor case on the output side of the steel motor housing. This side of the case will be completely welded & the opposite case side plates are removable for interior case access.
The electric motor is vented on the back side (pedal chain side) only so venting is required on this removable plate. The motor case is completely open on the bottom for cooling as well. If I encounter heating issues I've room to tube wrap the motor for liquid cooling, the aluminum fuel tank would make a great coolant tank. I don't see cooling as a big issue however I've reasoned appropriate responses if heat becomes a big problem.
Going with high power and small motor case size is new to me, but my other electric projects have certainly equipped me to expect some difficulties. I've studied the electric scooter scene and found the weight of the best high performance models to be between 70 and 100 lbs. unloaded. Not unlike that of cruiser style CG equipped moto bikes. Power to weight of a kit bike is miniscule compared to that of a 2500 watt electric so I'd think 4800 watts even more impressive. Torque on the electrics is huge. Compact size yet long on performance. The premium scooters are heavy and fast 40 to over 50 mph fast on tiny wheels. Same with the skateboard setups, only much lighter in weight. I mention speed only as reference points; my performance goals are still high torque & relatively modest top speed of around 40 mph..
I'll be playing with several battery and controller setups as well. Gearing comparisons between 10" or 12" wheel size and 26" bike size is sketchy in my mind at this point, but starting with 56 tooth on the rear and 12 tooth up front will determine if a reduction drive is required to lower the ratio. I'd not think raising the final drive ratio is even a thing.
Rick C.