Potential 2speed hub build

[Steve Churchill]

looking at this

https://lunacycle.com/double-gear-double-torque-motor/

I have a Mongoose Vinson with 190mm dropout. This with torque arms is about 150mm. How can I make up the other 40mm or am I just out of luck?

I have 2 RadRovers and this is to fit in with them. Wanted something lighter and when off trail it can be single tracked a bit. Most part smooth paths with smallish inclines.

I had originally thought BBSHD but that gets pretty pricey when compared to this setup.

Thoughts?

 

[George S.]

They cut the price on that motor by quite a bit. I think the rear option is new.

I think for small adjustments people use washer/spacers.

It's basically for steep hills. Luna has a video on YouTube. You could just buy a more appropriate fat hub for a lot less money if you don't have steep hills. Luna has a lot of hubs and now laces them. But you end up with fats and regular and front and rear, brake clearances. Too many combinations to sort out here. How light is light? The Golden Smart is maybe 14 pounds, but the controller is in the motor and really easy to build the bike. People are using Chinese vendors for Bafang hubs, geared and pretty light. I'm sure you can find something. I'm amazed by how much Luna carries. Nobody knows enough to sort this stuff out. Don't try to make something work if there is something that is designed for what you want off the shelf.

https://electricbikereview.com/forums/threads/two-speed-diy-hub.10978/

 

[Steve Churchill]

The geared hub on Lunacycles site looks like my radrover but it says it is for front wheels only. A kit like my radrover I could put on a much lighter bike might be nice.

 

[harryS]

I believe this is the same motor that's in your Radrover, and also in the Sondors for $145. It will have the 175mm axle. Might be too wide for the Vinson? It also only rate for 500W.
https://lunacycle.com/sondors-replacment-fat-bike-hub-motor/

You still need spokes, wheel, controller, e-brake levers, LCD, throttle, PAS sensor. Luna doesn't show on the website, but they got all these parts in their shop. Maybe they can quote you a package around that motor with a 4" rim. I think $450-500 would be a good deal.

I'm surprised that they don't have a rear geared motor kit with 175mm axle. Fatbikes are heavy enough that you don't need a heavy direct drive motor. My geared motor/rim weighs 12.0 pounds.

Mount a similar battery cradle on the Vinson, and you can swap batteries between it and the Radrover.

A year ago, I did buy that Bafang fatbike motor from China with 4" rim, and a complete controller kit. It was about $420 shipped, and they (cnebikes.com) took paypal so I felt good about the deal. Shipped in a week, and it's on my Walmart fatbike now.

If you want the higher power Bafang G.07.750.D, which is 750 W, you can get that shipped from China for $150, but you'll have to look for the rest of the kit on your own.