In fact it is easy to use the Ktm rear wheel with a zero fx.
What you will need is a 5mm spacer to feed in at the left side of the axle.
To have sprocket wheel and brake disk on the right place, it is also neccessary to put 3mm thick washers underneath the ktm brake disk. Then we need a 70 cleat counting sprocket for the Ktm wheel.
Here in Germany I found a dealer, which can deliver custom made sprockets from Aluminium up to 70 cleats.
That's it! I will post pictures within the next few days.
The benefits for using this wheel is a almost 1kg less weight.
Also the Axle of a Ktm can be used with the zero fx. Only the two sideparts for tensioning the chain need to be rasped down a bit to fit into the swingarm.
The Ktm axle has less weight 100gr, the brake disk has less weight 100gr and so on...
Alltogether now I could save about 6,5kg weight on my Zero Fx. It now has under 103kg with one Battery installed.
To do that, I was doing:
replacing the heavy mirrors to offroad usable, possible to foldable to the handlebar.
replacing the headlamp for a selfmade, only 140gr leight LED Lamp with 3500 Lumens.
removing the much too heavy rear plastic fender with light and replacing with a LED rear light offroad fender from Acerbis.
removing the onboard battery loader.
slimming the cable harness and sockets and plugs to less copper and smaller and less weight types of connectors.
removing the side stand.
removing the footbrake and installing the brake on the left handlebar side like a clutch.
changing the four iron distance pieces, that hold the motor in place from steel to aluminium.
I hope, i didnt forget a thing to numerate here....
It is easy to see, that one of the leading heads at zero came from Harley, if you look at the used material to build this bike.
If zero would really watch each gramm during inventing their Fx, they could easily bring it down to 100kg including one installed battery.
I will post some pictures and exact weight data next week, when I put in the rear wheel.
so long, best regards from Germany.
Chris.