How would you make a Rear Hub 12/14 mm axle Motor work on a 12x 143 through axle bike ?

I have been looking for a modern ( 8 years old or newer ) Full Suspension MTB Frame/Bike and what I am finding is that most of them have the newer style 12x 143 through axle rear frame.
Tried for several months now to find a slotted / drop out frame but not one yet that would work good enough for a rear hub motor for various reasons .
( remember that both the 12 mm and 14 mm axles on a hub motor have 10mm flats to slide up into the usual drop out )

I have been thinking about having a machine shop machine some nuts that are kind of like what is used in Furniture , something like this ... https://www.ebay.com/itm/M6-M8-M10-stainless-steel-allen-flat-nuts-hex-nut-round-head-sleeve-furniture-/222641344318

It would have to have a way for the axle to stop spinning so perhaps drilling a hole in the axle on the non wire side ?
or
How would you do it ?

I have pretty much guessed that the non wire side , most always the derailleur side , would have to be cut down so as to be able to angle the hub motor up into one side of the frame then push the hub to that side more in order for the other side to line up with the inside of the frame, then use some slotted washers on the inside of the frame

Would it work to make a spacer or two one for each side on the usual 135 mm on the hub motor axle , the spacer having a way to bolt it to something on the frame, like a torque arm , just on the inside ?

Your thoughts ? Diagram ?

Ebikes.ca check out there motors

Grin ( ebikes.ca) has only one through axle motor,
it is ...

1) only a front hub motor

2) very heavy since it is a DD hub motor.

It sure would have been good if Justin put all that effort into making a 7 pound or less weight , geared Rear Through Axle Hub motor .
or a 5 pound or less weight front hub through axle hub motor.

If its a thru axle frame with removable dropouts you can fabricate custom dropouts

Or you can wait for grin to make a rear version of their through axle motor

Why do you need to do this on a frame with a through axle?

There are just a couple of frames that I have seen that have removable dropouts, they were/are older 26 inch wheel ones ( I have two 27.5 inch hub motor wheels , and one 700c/29 er wheel ) and those few that I know of sold new for thousands of dollars , so they are not cheep when they do come up for sale on Craigslist.

I have been waiting for years now already for a rear through axle hub motor, and Grin made the front one ... a heavy DD motor.

Is Grin working on a 12mm axle , light weight , geared , 10-11 speed cassette ready ... rear , through axle hub motor ?

I need to do this on a frame with a through axle because ..

1) I already have a few hub motors build up in 27.5 and one 700c wheel.

2) I want to have a frame designed for 27.5 or 29 er wheels ( see # 1 )
and
I want to have a frame that has a tapered head tube so that I can put the newer/better quality and often lighter weight as well ... tapered forks on it.

3) The used bikes I am finding on Craigslist that have the older style dropouts are so used and beat up that I am hesitant to go faster and put torque through the rear of the frame.
I am finding however many newer bikes that are the new through axle design that have very little use .
Bike frames have gotten better in the last 7-8 years now , that is when most of those improved frames also went to the through axle design. So it is hard to find a newer better frame that still has the older slotted dropouts.
And most of those have very low end components on them , like the Diamond Back Recoil, etc.

It would be good to start a list of bikes that have removable rear dropouts .
So far I know of only 3 ... A very old Tomac Frame, one Intense Frame, and only 1 frame from Giant.

Know of anymore ?

tolkaNo said:

If its a thru axle frame with removable dropouts you can fabricate custom dropouts

Or you can wait for grin to make a rear version of their through axle motor

Why do you need to do this on a frame with a through axle?

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The more I think about how to do this , the more I realize that the larger more powerful rear hub motors with 14mm axle are just going to be too hard to do, first the frame axle holes would have to be drilled out larger and that would be hard to do correctly , getting it straight with a hand drill at home .

And perhaps the frame would have to be drilled out on one side and slotted on the other side in order to angle the one side of the axle of the hub up into the frame then put the other up into the slot .

All this could be done, but If not done correctly a new rear swingarm would have to be bought from the bike Manufacturer.

Bafang has a thru-axle geared rear hub. Unfortunately it comes in boost width only.

http://www.bafang-e.com/en/components/component/motor/rm-g040500dc.html

There are more and more Boost/Plus + wheel size bikes available each year, so this looks good. It has the spec's ( weight and voltage range ) of the Mac only less power . Wonder about the amp max, I can run 30 amps through the Mac, some people run a little more 35 or so.

However I keep looking at the axle and it does not look like a through axle , but a quick release. Is there a youtube video of it being installed on a bike ?
The website does not show how it would go into a through axle frame . I would love for it to be true.

Did you find out the cost and what controllers it works / comes with and the cost of that and display ? or does it work with any infinion clone controller ?

1N4001 said:

Bafang has a thru-axle geared rear hub. Unfortunately it comes in boost width only.

http://www.bafang-e.com/en/components/component/motor/rm-g040500dc.html

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It's the Bafang H800. Googling that name yields some articles and pictures. http://www.radmarkt.de/nachrichten/bafang-leistungsstarker-hecknaben-motor-fuer-e-mtbs-speed-pedelecs

Looks like it needs special dropouts with groves to act as a torque arms. Bah. No information on pricing or availability either. You can probably only get them in bulk.


The only other thru-axle rear hub I know of is the Go Swissdrive. https://www.go-swissdrive.com/en/the-go-swissdrive-system/motor/

It uses an universal torque arm design. However it's a heavy direct-drive and only sold as an expensive set. I once considered the idea of grabbing a defective 500W motor off of Ebay and exposing the phase wires for use with an external controller, but I haven't had much luck finding any. They're super rare.

The other option besides removable dropouts, is to fabricate the whole swing arm. If you go this route, make it 3" longer.

I have actually have thought about that several times, the only thing holding me back is that I do not know anyone who could design , drill , machine and weld it together.
Perhaps if someone could do a few of them for a good price each I could buy one from them.
There would be a market but it would be few as I have a Santa Cruz simple single pivot , Frame.


I would have someone make some adaptor plates on each side of the rear dropouts that would also do this, but I do not trust the rear swing arm that my current FS bike has ( Santa Cruz Bantam/Superlight/ etc . ) the dropout area is a small one that is welded to the very close together seat and chain stays ,
and the other bike designs that I would like are the Specialized ones that have that horst link that would complicate doing that .

If the cost of making / having some make me a swing arm is over say about $ 150 shipped , then perhaps that money would be better spent on a mid-drive, which is what I really want. The problem is the people developing the newer RC motor mid-drives that I want are taking a very long time in development and production, which is why I want to do this in the first place.
Would love it if a light weight aluminium or even steel one that was light enough that looks much like the one on the Enduro, Stalth Copy frames could be made and sold for around $ 100 . I could contribute to the design by way of simple drawing on paper .

dogman dan said:

The other option besides removable dropouts, is to fabricate the whole swing arm. If you go this route, make it 3" longer.

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For what it's worth, geared rear hubs have a tendency to self destruct off road. The first time you catch some air and you still have some throttle on it often blows up something in the clutch during the landing. It's a frustrating feeling to be on the trail and hearing the motor spinning inside the shell, but not making the wheel move. :x

Good information to know, I ride 100 % of the time on the road these days, that is because I have no car to take me to the trails and no motor on the F.S. bike . my two hub motors are on Hard Tails, and I am trying to sell one at this time to raise funds for the next project.

I do want a mid-drive to go up mountains , but even then it will be mostly on roads. I am lucky to have great canyon roads with plenty of curves , all over the place around where I live.

What you say is another reason I am always looking for the lightest weight motor that will get the job done.

With each passing month I am thinking the long term goal is to have a very small and light weight motor that is located right on the swing arm , the swing arm longer of course, but with the kind of riding I do I have been wanting a longer swingarm for quite a while now anyway. I have read about your's and dogman dan's bikes going back a few years now and even years before that learned about the benefit of longer wheelbases.

With a longer swing arm it would also solve another problem I have seen on higher speed bikes , that is the need to use larger outer chainrings to keep leg cadence pace up with the motor. One just needs to make the front part of the swing arm thinner than the chainstays that go around the tire. that has been done on some production peddle bikes in the past already .

Voltron said:

For what it's worth, geared rear hubs have a tendency to self destruct off road. The first time you catch some air and you still have some throttle on it often blows up something in the clutch during the landing. It's a frustrating feeling to be on the trail and hearing the motor spinning inside the shell, but not making the wheel move. :x

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