Idea for an electric push trailer... Help for a big guy...

[Bigkat650]

I have designs for an electrical push trailer which I think I may try and build. I am looking for an assist in peddling, since I am 300+lbs--and live and commute over some decent hills. I would like to post my needs, and what I am currently thinking.

Needs:
-30+ Miles on a single charge- I would be peddling the whole time, using the motor as a boost in speed and assistance up hills.
-15 to 20 MPH cruising speed with low to moderate peddling
-Assistance climbing hills
-Easy to put on and take off of mountain bike
-Keep the system as inexpensive as possible ($350-$400 or less for all parts except metal for the frame)

What I am looking at:

MOTOR:
http://www.monsterscooterparts.com/...drive-electric-motor-rear-wheel-assembly.html
or
http://www.monsterscooterparts.com/36vo10wadidr1.html
**I do not know which would be better for my needs. I have some hills that are pretty steep, and I don't mind peddling to get up them, but I prefer if I could peddle kinda easy (so I didn't have to stand up)

BATTERIES
http://cgi.ebay.com/4-Pack-12-Volt-..._UPS?hash=item27aa6702ce&_trksid=p3286.c0.m14
**I would get 6 batteries total and run either 36v, 24ah for the 1000 watt motor, or 24v, 36ah for the 450 watt motor.

Below are the 3D images I made to get a basic idea of the plans for the push trailer. I made this before I found the motor/drive system listed above, but the application is similar. The idea is to be able to strap something (like a cooler) to the top of the platform above the batteries.

I have no experience in this, and my calculations are all best guesses. The questions I have are:
-Does it seem viable?
-Is it better to attach trailer to rear axle or below the seat?
-Which drive system would be better for a large guy of my size. I want the best combination of distance and speed with pedal assist. Thanks everyone, and I am going to continue to look around this forum for more answers.

 

[mwkeefer]

Hello,

Personally I would go with a seat level mount for the trailer... also I might use some more "off the shelf parts" to build a push trailer like this...

First do you want to carry cargo? If not, then the trailer doesn't need to be so large or wide.

Second... are you firm with the brushed motor or batteries of choice? I ask because a simple way to build your trailer would be to get a used steel 24" front fork and bolt it down to a piece of plywood, then mount a 24" hub wheel in the fork (cutout the plywood where needed). Personally I would use LiPo for range and cost per wh but anything would suffice (even heavy AGMs) but by reducing the weight a bit you will only be pushing yourself.

Going up hills this design has a tendency to slip, a rear trailer could jackknife going up hill... just a thought.

My first ebike was a trailer simliar to yours, i hacked up my ESR 750 GoPed and made a drive trailer... bolted to a seat clamp... I was seeing approx 12-15mph using this with approx 8-10mi range (4x7AH SLA @ 24v/14AH).

Regards,
Mike

 

[Rassy]

Bigkat650, do a search on the forum with the words pusher and trailer. You will find some pretty extensive discussions and experiences with pusher trailers. Good luck with your project.