Front hub motor + rear pedal hub = all-wheel drive bike. Anyone done it?

zanq

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I don't have the cash for this project at the moment so this is me mostly thinking out loud. I hunt a friend's property where, in the past, we have used ATVs or walked to the hunting blinds. This friend sold his ATVs so it will be back to walking. I'm fine with that but stealthy, wheeled access to the blinds would be nice.

Years ago I attempted a "hunting bike" setup but this was on narrower MTB tires dealing with chisel-plowed fields (read: EXTREMELY rutted). It did not work well. This was before "hunting bikes" or fat bikes were a thing (Cogburn, Rambo......guess I missed the boat on that idea). I had too much gear, sank into the soft dirt, and could not maintain any momentum.

Now I have a Surly Orge with a Salsa Enabler (135mm) fork with 29x3.0 tires (on 35mm rims, they fit). It got me thinking about attempting a hunting bike setup again and going a step further with an electric hub motor/wheel for a fat bike on the front. Has anyone done something similar? How well has it worked? It would be something I take on/off whenever needed.

I've read that a front hub motor does have several cons, including lack of traction. I don't know how concerned I should be:

https://www.electricbike.com/hub-mot...r-wheel-drive/

Running perpendicular to the chisel-plow ruts is tough, even on a 4x4 ATV; it's difficult to walk at times. Running in the rut (parallel) would probably work on 2 wheels provided I had enough flotation (hence the fat bike tire). I would also be pedaling but use the front motor to help maintain momentum, so I would be all-wheel drive.

I'm also not above buying something like a Sondors ebike ($600) and adding a front hub motor to make it all-wheel drive if that approach has more value.

I'm pretty naive about ebikes, kits, specs, etc. so I'm trying to get up speed and would appreciate any input.

Thanks!
 

zanq

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If were talking about my Surly, I'm not sure that I would. Either I'm pedaling (front hub coasting; assuming they can freewheel/coast) or relying on the electric hub to keep me rolling forward (while I pedal to help or coast to maintain balance). I could be 100% wrong on how this would work.

If we are talking a dedicated, all wheel drive electric bike, I'm not sure how they would be sync-ed.
 

Flamingtaco

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There is no need to sync anything. The only consideration is control of power output when you have enough on tap to easily break traction.

A pedal assist controller would work best. Changes in pull pull from the front wheel during tight cornering (changing traction conditions) can turn out poorly.

Power to the front wheel is going to generate lift at the front the frame, as opposed to downward force on the rear when applying power to the rear wheel. Suspension forks are designed for the forces that push the fork rearward and compress it under braking conditions, so there could be anomalous behavior if you have too much power on tap.
 

northernfatbike

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If you install a geared front hub motor it free wheels when you not powering it. Everything I,ve read says a steel front fork is best and you should use 1 or even better 2 torque arms on the forks. I do have an electric assist road bike and I just bought a fat bike that I,m thinking about giving it a front hub motor as well.
 

Count

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Hello forum, I have created a very functional 2 wheel drive ebike. I started with a 2020 Rad Runner, and upgraded with a suspension front end, 35A controller, color display, and true 750w Baffang motor. Lots of other upgrades and additions, but not relevant here. I installed 1 1000w front hub motor/wheel combo from Amazon. The twist throttle is on the left hand side. Pretty much plug and play!

Despite having read to the contrary, I observe NO issues which could be considered unsound or unsafe. There is no "syncing" needed, you just turn the throttles as you wish. I have tripped a thermal breaker (I think) on the BMS in the stock 48v battery, when nailing both throttles simultaneously, but it resets in a minute or so. It has only happened twice, so it is not super sensitive, but I am asking it to deliver well over 2000 watts!

With the rear hub motor alone, I get a strong 24 MPH, with pretty good acceleration, and PLENTY of power. In fact, my first ride with all of the upgrades (exclusive of the front hub motor), I did a very unexpected wheelie and almost lost the bike from under me! Huge power. With the front motor alone, I get up to 30 MPH, with less power and less acceleration. There does not seem to be any advantage to using both together, but no negative issues either.

I created this bike to ride well on soft beach sand. I ride a lot on the beach, and it is often necessary to cross wide swaths of soft sand, in order to reach the packed, hard wet sand. W/O the front motor, the front wheel tends to just plow through the sand, not over it. The bike also hunts left to right, seeking traction, w/o the front motor. If you use the front motor alone, yes, the front wheel just spins with virtually no traction. However, in unison with the rear motor, it crosses soft sand like a dream! Would I recommend it? Only if you had a need like I did. Otherwise, it is just a fun indulgence!
 
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zanq

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Hello forum, I have created a very functional 2 wheel drive ebike. I started with a 2020 Rad Runner, and upgraded with a suspension front end, 35A controller, color display, and true 750w Bafang motor. Lots of other upgrades and additions, but not relevant here. I installed 1 1000w front hub motor/wheel combo from Amazon. The twist throttle is on the left hand side. Pretty much plug and play!

Despite having read to the contrary, I observe NO issues which could be considered unsound or unsafe. There is no "syncing" needed, you just turn the throttles as you wish. I have tripped a thermal breaker (I think) on the BMS in the stock 48v battery, when nailing both throttles simultaneously, but it resets in a minute or so. It has only happened twice, so it is not super sensitive, but I am asking it to deliver well over 2000 watts!

With the rear hub motor alone, I get a strong 24 MPH, with pretty good acceleration, and PLENTY of power. In fact, my first ride with all of the upgrades (exclusive of the front hub motor), I did a very unexpected wheelie and almost lost the bike from under me! Huge power. With the front motor alone, I get up to 30 MPH, with less power and less acceleration. There does not seem to be any advantage to using both together, but no negative issues either.

I created this bike to ride well on soft beach sand. I ride a lot on the beach, and it is often necessary to cross wide swaths of soft sand, in order to reach the packed, hard wet sand. W/O the front motor, the front wheel tends to just plow through the sand, not over it. The bike also hunts left to right, seeking traction, w/o the front motor. If you use the front motor alone, yes, the front wheel just spins with virtually no traction. However, in unison with the rear motor, it crosses soft sand like a dream! Would I recommend it? Only if you had a need like I did. Otherwise, it is just a fun indulgence!
Hello @Count, thanks for posting your experience with your 2WD ebike. It's sounds like a fun bike! I'm still considering options. I did manage to find the following front ebike kit with a 29" wheel to suit the Salsa Enabler (135mm) forks.

https://www.ebay.com/itm/Conversion...9-inch-Electric-Bike-Motor-Wheel/254408267746

In this case I'd go with the rear hub kit and fit it to my front forks, since the spacing of my front forks is 135mm and they are also setup to use rear disc hub spacing.

I'm glad to hear you can draw from the same battery for your front and rear kits. This eliminates some complexity!
 

Count

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FWIW, this is the wheel kit I ordered. I did not use the PAS or the electric brake wires or cables or brake handles. Front dropout is 5 5/16" (which IS 135mm)! The wheel is 20" x 4", which matches the old one. I see the kit you are looking at is 1500w, which is HUGE in the ebike world. That looks like a great complete kit!

 
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