I've been struggling to commit to an engine and battery combination. A Permanent Magnet motor and 40AmpHour batteries, will give me a very light bike, but will sacrifice durability and range. On the other hand, a 6.7" Series Wound motor with 60 AH batteries will give me the durability and range, but the extra weight means less acceleration.
The bottom line for weight is staying true to the project goals. The end result has to be a "bolt-in" kit. The average gearhead/propellerhead should be able take his Gixxer and yank the ICE motor, put in my battery frame and motor mount, then attach the components of his choice. If the project is significantly heavier or lighter than the original factory weight, the suspension components will need reworking ($$$).
So here's the weights as measured or estimated (*) assuming the heavier motor and batteries:
Rolling Frame 160
Brackets & Fasteners 32
Body Work 38
Battery & Motor 188
Missing Cosmetics 10*
Motor & Batt. Mount 20*
Chain & Sprockets 15*
Charger (external) 0*
Total 473 ( Factory Dry Weight: 456 lbs )
The PM motors are about 20 lbs lighter, so that would allow the kitted EV bike to use either motor without being too far off base.