Winter is coming and last winter me and the kid agreed on needing fatbikes to ride on the snow..
Of course they’d need powerful motors enough to propel them through the snow and not bog down even when hitting deeper pockets of powder. At first I planned on building my own frames, but as summer came and went and I didn’t have time to get going I decided to get a test frame to start building on to see if our planned setup would pan out..

So, this is what I got:

It’s a chinese clone of a “Stealth bomber” type frame, made entirely from 2mm steel, making it both heavy (20+kg) and sturdy. We’ve got 20″ fatbike wheels on there and personally I think it looks sick. 🙂
The rear suspension I just stole from another bike we’ve previously built and gutted, and the front suspension is a 190mm travel air-sprung fork made 100% from chinesium, but it still seems of rather OK quality.

To get enough power to have fun on these we’re going to use LightningRods BigBlock motors, good for somewhere in the vincinity of 14kW. We’re going to build a couple of hefty 72v battery packs with at least 30Ah capacity and using either ASI BAC2000 or BAC4000 motor controllers to translate the battery DC current to pure joy on the rear wheel.

And yeah, there probably won’t be any reason to put pedals on a bike like this, so we won’t. Footpegs’ll have to do. Since this frame is originally built for hub motors and we’re not using that there are modifications to be made. We’re probably going to fit the motor right where the rear suspension sits right now and move the suspension upwards. A single stage 219 chain reduction will translate the power from the motor shaft to the rear hub. Then we’re building motorcycle style seats to go on the bikes too, some kind of twist throttle, hydraulic brakes, probably have to make my own studded wheels, lights (since it’s mostly dark in the winter) and possibly a kickstand..

Well, that’s the plan. We’ll see how it works out and if we get to ride it this winter. As it sits now the frame, wheels and suspension is in place. I’ve got the motors and controllers but no batteries or other electronics needed. Next week I should get the chain and prockets to be able to start manufacturing adapters to mount stuff where it’s not intended to go and I’ll post updates whenever I get around to it.
First I’ll need to do some modifications to the CNC plasmacutter though to be able to precision cut the parts I need for this project, so that’s next..