Push Trailer

finally got all the components for the 1000W 48v push tailer..

BOB copy trailer, reinforced and braced and new alloy 4mm bottom
hitch squewer on rear wheel was upgraded to shimano hi ten steel

22AH agm SLA's weigh 24.4kg and are way too heavy!!

9AH agm SLA's weigh 9kg but the controller keeps hitting low voltage dropout on big hills so no good!!

LIPO is the answer but I dont want to spend the cash, sugeestions? packing yourself etc/

pics/






here is a video, big torque with the 22ah batteries

Nice push-trailer! Here's a thread with a dozen others (I will add yours if you don't):

http://endless-sphere.com/forums/viewtopic.php?f=6&t=9855

What specific tire is that (looks beefier than average)? Why did you choose a push-trailer instead of a frame-kit? why a single-wheel as opposed to a 2-wheel? For the benefit of others who want to copy this, If you had more money to spend on it, you would have __________?

once I have the mix right I will start building these for ppl in Australia..

why a trailer?

I have a $3500 29er X-country MTB that I ride and race on trails, I love this bike and it has high spec'd components, with a trailer I can unhook the trailer and disconnect one single cable and it is a normal MTB once again!! so I can have one bike to do everything instead of an ebike and a good MTB.. it actually is cheaper to buy a 1000W 48v trailer with batteries, charger, controller etc for $1500 and put it on any bike than to have an ebike and multible other bikes!!

single wheel for agility

the motor kit is a 16" scooter motor hence 16 x 2.5" great traction..

D

spinningmagnets said:

For the benefit of others who want to copy this, If you had more money to spend on it, you would have __________?

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I like that question spin.
Of course if money was no object then things could really start getting wild.

On my trailer I really wanted to add a geared hub like a Sram DualDrive, Strumy-Archer, Rohloff, or NuVinci(mmmhmmm). A geared hub would have alleviated the chain path alignment problem and would have allowed a shorter body length.
Any of those but the NuVinci would probably require a stepper motor setup for precise shifting and, obviously, quite a bit more scratch... Any of those except maybe the Strumy-Archer would have easily doubled the cost of the trailer unless it could be picked up at a deep discount.

I would have liked to use aluminum honeycomb for the box in a uni-body type construction and eliminate the Burley trailer.

And last but not least, I would have loved to used something like a Schwinn Stealth direct drive and motor to get rid of some of the current geared motor's noise.

damonjackson_spl ***in the other thread*** said:

very very good power and massive low end torque for climbing, flats is slow around 25/30km/h but can climb very steep grades!! for my commute of 15km from 0m to 556m above sea level is nice for me!!

might be better with 500W motor and 7ah batteries?

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Prolly much worse...

The larger rated motor can shed the heat from high current longer. A smaller motor will still try to draw 1KW and smoke.

Of course, lighter lipo batteries are desirable; but less throttle or a boost-pack for momentary peak power could reduce the LVC issues.

TylerDurden said:

Of course, lighter lipo batteries are desirable; but less throttle or a boost-pack for momentary peak power could reduce the LVC issues.

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Lighter batters are desirable, but it is possible to go too light on a trailer. I went from SLA to LIPO4 on my trailer and found that the trailer tire wore out very quickly. It wasn't noticeable while riding, but the trailer tire was not getting good traction and slipping which caused the wear. If you go light and experience the same problem, you might be able to use both lipo and SLA to get the traction you need.

Bubba

damonjackson_spl said:

I can unhook the trailer and disconnect one single cable and it is a normal MTB once again!

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Seems like it needs another wire or two for a brake override. I have no experience with a push trailer, but it seems like things could much uglier than on a regular rig if some malfunction resulted in WOT with a thousand watts back there.

Maybe a couple of 8-conductor SpeakOn connectors as in http://www.audiogear.com/cgi-bin/shopper.cgi?key=NA4LJ&preadd=action... plus their in-line connector to join two of those things as in http://www.audiogear.com/cgi-bin/shopper.cgi?key=NL8MM&preadd=action.

Then there would still be only one "connect/disconnect" task, but the possibility of more services.

PeteCress said:

Seems like it needs another wire or two for a brake override. I have no experience with a push trailer, but it seems like things could (get) much uglier than on a regular rig if some malfunction resulted in WOT with a thousand watts back there.

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To be fair, Damon said "one single cable" not one conductor.

I needed 9 conductors for my trailer harness, 5 for the scooter throttle and 4 for the remote shifting. I used an old atx power connector cut down to 10, one pin is unused. I thought about taking it to 12 conductors for brake cutoff capability but I didn't want to have to retrofit switchs to the GT's brake handles.



I do agree with you about a WOT malfunction.
Without any type of load, I doubt my trailer would push the bike if it was lying on the ground. If it had a load on it I doubt it could push it much but I'm sure it could really tear things up if I wasn't able to shut things off quick enough.
If I was riding a light load on level ground I think the brakes could still stop everything in short order.

WOT malfunction + downhill + heavy loaded trailer= I'm sure it would get my full attention quickly.

I've thought about adding some sort of emergency disconnect somewhere on the trailer. Adding it to the bike would require big gauge wires unless it was something like a brake cable one could pull. But then that would require yet another thing to hook up when connecting the trailer...

zap said:

PeteCress said:

I've thought about adding some sort of emergency disconnect somewhere on the trailer. Adding it to the bike would require big gauge wires unless it was something like a brake cable one could pull. But then that would require yet another thing to hook up when connecting the trailer...

Click to expand...

Click to expand...

My thoughts would turn to a wire with a couple of Anderson plugs inline that somehow get yanked apart if/when the angle between trailer/bike is more than a certain amount (90 degrees?).... Yeah, a certain small PITA factor when backing the trailer or otherwise maneuvering it in really close quarters... but in the even of some unforseen crash scenario it might keep things from getting any uglier.

yes one cable to the twist throttle..

the throlttle also has LED power indicators and a kill switch..

pfffffffft malfunction, if the kill switch doesnt work then the gauntlet will be run!!