Springer forks tend to have nice thick beefy dropouts, as long as you make sure have the 10mm flats and proper width they would be perfect candidates.

Yes the E-BiktKit battery will supply the required power for the BionX kit, however it will require some creativity to make it work, the BionX battery has electronics inside that communicate with the BionX dash display, you would have to tap into that. The BionX battery box and electronics don't care what chemistry feeds it as long as it's a 36v pack, the E-Bikekit is LiFePo4 and the original BionX is LiMn The difference is that the LiMn chemistry starts off higher voltage but drops gradually as the ride does on, the Lifepo4 tends to run a more steady voltage all the way thru, i'm not sure how this will work out with the battery gauge from the BionX but it will work just fine as far as power output goes. If you search on the Endless Sphere forum http://www.endless-sphere.com/forums/index.php This may help: http://www.endless-sphere.com/forums/viewtopic.php?f=2&t=7813&hilit=bionx+battery