Trailer with hub motor, anyone try this?

EMGX

Well-Known Member
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How would you sync it to the bike? if it is going too fast thats going to cause problems too slow its going to drag.
 
This is a front MXUS 36v 250w geared motor that I bought years ago as a basic kit laced into a 26" wheel. It was very inexpensive, bought off of Amazon, under $150 for the motor/wheel, controller, throttle, no battery or display. At the time my employer was thinking of moving my location from a 26 mile commute to a 11 mile commute so I was hoping to bike once in a while. I live in a hilly/mountainous area and for some very steep long portions wanted assist to help with the hills. Unfortunately the motor didn't have the power to help where I wanted assist. I could ride the route on a regular bike but would have arrived a work sweaty and tired. My employer decided against moving my work location so I didn't need it anyway. I did try it on a few bikes including a Dahon Jack, an old Sears 27" 10 speed that I converted into a 26" 3 speed, an old Schwinn Sierra mountain bike and a couple other bikes. It worked really well on flat to mild/moderately hilly routes where I didn't need or want assist but just stalled out and was a useless boat anchor on the really hilly stuff where I did want assist. So it just sat in a shed for years. 2-3months ago I laced it into a 16" rim to try on a single wheel "Bob" type trailer but I haven't done anything else with it yet. I do have a good 36v battery that I can use.

I think the torque rating on this motor is 30nm, lacing it into a 16" wheel instead of the 26" should provide ~1.6x the assist at speeds up to 12-13mph (vs 20+ it could do in a 26" wheel). I'd use it with a throttle to provide assist only when I want it. I have done some few day touring with my mid drive BH gravel bike but I have a Walmart Schwinn Avenue aluminum frame bike that is sturdier than the BH and I'd like to take that bike on some few day tours in Washington and eastern Oregon this spring where a trailer would be nice as well as some assist when needed.

here is the bike that I would like to use it with for some touring

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So you're considering that this would be a 'pusher' trailer where the trailer's hub motor can be used to help push the trailer and the conventional bike it's attached to? I toyed with a similar idea several years ago but decided against it based on threads like this one; https://endless-sphere.com/forums/viewtopic.php?t=97691.
 
So you're considering that this would be a 'pusher' trailer where the trailer's hub motor can be used to help push the trailer and the conventional bike it's attached to? I toyed with a similar idea several years ago but decided against it based on threads like this one; https://endless-sphere.com/forums/viewtopic.php?t=97691.
Right, a pusher trailer, I think that I've seen a single wheel pusher trailer commercially available. Thanks for the link - it looks like they were talking about high power heavy/heavily loaded. The aluminum single wheel trailer that I have is very light weight and it wouldn't be loaded too heavily. My main concerns are if the dropouts are strong enough (I can make torque arms) and if the axle skewer that connects to the trailer is strong enough. I have tested the trailer stock with 50 pounds load and it was very stable.
 
Why not just buy one thats already made ? Google showed a bunch .
I have had a trailer for a few years already, just want to try adding the motor which I have already laced into a 16" wheel as shown in the image.
 
I ended up building a DIY front hub drive bike that had plenty of power to tow a conventional single wheel trailer. The trailer came with a replacement for the bike's rear wheel skewer that worked well for the years I rode this bike.
 

The trailer I have is identical to this one. It has an axle skewer attachment.
The motor I have doesn't provide enough assist to be helpful on steeper hills where I want help but in the 16" wheel it should provide 1.6x the torque effect vs when it was in a 26" wheel. I'll have to just give it a try to see if it works well in this application. The spokes and 16" diam rim were only ~ $30 so it is a cheap project.
 
@EMGX The whole time I was reading this thread I was envisioning a trailer that attaches to a seat post with a pivot and thinking that it's guaranteed to jackknife as soon as you hit the throttle. Seeing that the trailer has a rigid attachment to the bike via the rear axel makes me think this might work, provided you have enough weight on the trailer so the hub motor wheel has sufficient traction. Keep us posted with updates and photos, this is going to be interesting. Maybe you have stumbled onto a way to add electric boost to any bike with a rear skewer!
 
I get a kick out of this I had pulled a 200# loaded trailer on my recumbent 10 miles. a e bike should do Fien without a motorized trailer.
 
The trailer I have is identical to this one. It has an axle skewer attachment.
The motor I have doesn't provide enough assist to be helpful on steeper hills where I want help but in the 16" wheel it should provide 1.6x the torque effect vs when it was in a 26" wheel. I'll have to just give it a try to see if it works well in this application. The spokes and 16" diam rim were only ~ $30 so it is a cheap project.
@Rich Wolf is a member here, he made exactly what you are describing, a pusher e-trailer, and developed a few models. I remember Court doing a review of one. I don't think the company is still in business and there is a new (no affiliation as far as I know) ebike company using the name now.

Maybe some inspiration. He used a really well constructed wheel and motor. You should be able to use what you have. You can look back at Rich's posts for more info.


 
I get a kick out of this I had pulled a 200# loaded trailer on my recumbent 10 miles. a e bike should do Fien without a motorized trailer.
I want to use the motorized trailer with a regular pedal bike, not my ebike. I did a 3 day 175 mile tour route in eastern Oregon this past summer on my Yamaha powered gravel bike. It did really well overall but the frame isn't as sturdy as my Walmart Schwinn bike. With panniers on the back it felt like the rear of the frame was flexing when I would stand to pedal up hills. I also took the Walmart Schwinn on a 2 day 120 mile ride in Idaho a week or two earlier. Overall I like that bike better but would have appreciated some assist. I don't want to add a motor to the Schwinn because I don't want to make it a heavy bike, a mid drive would also take away the triple chainring and I would lose the wide gearing.

The Schwinn on the ride in Idaho
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The BH gravel ebike on the ride in eastern Oregon
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@EMGX The whole time I was reading this thread I was envisioning a trailer that attaches to a seat post with a pivot and thinking that it's guaranteed to jackknife as soon as you hit the throttle. Seeing that the trailer has a rigid attachment to the bike via the rear axel makes me think this might work, provided you have enough weight on the trailer so the hub motor wheel has sufficient traction. Keep us posted with updates and photos, this is going to be interesting. Maybe you have stumbled onto a way to add electric boost to any bike with a rear skewer!
Nothing new , they have been around for quite a while just never caught on big .
 
I put a 1000w Golden Motor with a LiFePo4 battery on a BOB Yak 10yrs ago that I attached to a rigid hardtail 29"er. Actually even before that I had mounted a Honda 35cc 4stroke on a kid's trail a bike with a Stanton gear box. The big difference, other than gas vs. e, was the attachment. The trail a bike fit onto the seatpost and as noted above made for some interesting cornering maneuvers and I found that the axle attachment was far preferable although you still didn't want to get to goosey with the throttle in a tight turn situation.

My reasoning was that with the trailer I could use it on various bikes as the only thing on the actual bike was a throttle and some wire. Which does point to the fact that you pretty much are going to be throttle only using a trailer system as it would be hard, not impossible but more complex, to provide for PAS. I still think it's a good idea for road type use and had alot of fun with it BITD. It would launch the steepest streets in town and the traction wasn't bad via carrying the brick battery in a nylon ammo can in the trailer itself helped with that. Once in awhile it would bounce off bumps losing traction momentarily but not excessively.

I still think it's a viable idea but doesn't work for my needs at this time being more focused on trail and logging road type riding.
 
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@Rich Wolf is a member here, he made exactly what you are describing, a pusher e-trailer, and developed a few models. I remember Court doing a review of one. I don't think the company is still in business and there is a new (no affiliation as far as I know) ebike company using the name now.

Maybe some inspiration. He used a really well constructed wheel and motor. You should be able to use what you have. You can look back at Rich's posts for more info.


Thanks, I hadn't seen that. Same idea but he uses a direct drive which would add some resistance when the motor wasn't being used. The geared hub motor I have freewheels without added resistance. I don't plan on using the motor assist except when needed and I don't need to go as fast as he does, nor ride without pedaling. The top speed of the motor when it was in a 26" wheel was a bit over 20mph so it should top out around 12 or 13 mph in the 16" wheel, that is fast enough since I would only use on hills or into the wind where my speed would be low anyway.
 
Nothing new , they have been around for quite a while just never caught on big .
I wouldn't expect that there has been much of a market for something like this. I wouldn't have even considered it except that I already have the trailer and the motor. The only expense has been to buy the 16" rim and spokes so I thought I would give it a try. If it does work well I plan to use it for some short touring this spring.
 
I'm not moving very fast on this but here it is in the trailer dropouts. I think it will work.
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Looks like it fits just fine. Are you planning on carrying the controller and battery on the trailer?

One suggestion is to make a small torque arm that goes from the axle up to that braze-on. It would take the place of the tab washer, which in my mind are pretty useless at handling torque loads, and you would still be able to attach that stay using a little longer bolt.

You will have fun with it for sure.
 
Looks like it fits just fine. Are you planning on carrying the controller and battery on the trailer?

One suggestion is to make a small torque arm that goes from the axle up to that braze-on. It would take the place of the tab washer, which in my mind are pretty useless at handling torque loads, and you would still be able to attach that stay using a little longer bolt.

You will have fun with it for sure.
I do plan on making some simple torque arms that will butt up under the stays since the rotational torque would be counterclockwise. I'm motivated to finish it up because I'm curious if it will work in a useful way but it is too cold in the garage to spend much time on it. Not sure if I will put the controller and battery on the trailer or on a back rack on the bike, probably on the trailer. I have touring plans for it if it works really well.
 
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