Amberwolf's Single-Wheel Pusher Trailer

I started this idea in my kennel trailer thread:
http://endless-sphere.com/forums/viewtopic.php?p=306751#p306751
but it needs one of it's own for me to develop it separately.

The idea is that this Freecycle.org find:

will become a single-wheel pusher trailer, that I can clamp on the seattube/post of any of my regular bikes.

It won't fit DayGlo Avenger or CrazyBike2, due to the rack on DGA and the seat design on CB2, but The Velcro Eclipse will work (although it already has a front hub right now) and so will the Schwinn Sierra or other regular DF bikes. Depending on how I make the rear end it may also fit the semi recumbent cargo bike being worked out in another thread.

The trailer folds right now for storage and locks with this

if I take care in designing any drive systems for it it should continue to do so.

If I take the handlebars and seat off of this trailer:
http://endless-sphere.com/forums/download/file.php?id=44785
I can bolt a platform across their mounting points, and put something down the side of that to keep anything from touching the rear wheel and any drivetrain, and use these as soft cargo bags:

They were originally big computer-tower carrying cases from CompUSA's old training classes stuff; I considered using them on the bolt-together semi recumbent cargo bike originally and there are pics in that thread:
http://www.endless-sphere.com/forums/viewtopic.php?p=247481#p247481

It is likely that at first, to test how safe it is to use as a pusher, that I will use a hubmotor wheel in place of the existing rear wheel and pedals. Since the current freewheel is rusty:

that's a quick way to check out the idea. It was rusted so much that it would not freewheel. A squirt of WD40 mixed with gearbox oil fixed that, though it's still very loud and probably needs scrubbing out. Chain is rusty but works at the links.

Also, there is a neat little flagpole holder already welded onto the rightside dropout area, with a couple feet of stub of the old pole still in it. I'll probably fix that up with a flag.

It is a 24" wheel, and I may have to cut the brake-crossmember and the "kickstand plate" (neither of which have holes in them to bolt those things to, but are present nevertheless) to allow tire clearance.

My only question is whether I should lace up a 24" wheel with the 1000W GM/9C hybrid, or just use the FUsin or 9C hub in their existing 26" wheel.

After I verify that it will safely work as a pusher using a hub, I'll see about converting it to use a chain-driven wheel from a motor like a treadmill motor or something, just to see if it'll work, and to get back into making my crazy drivetrains that I have not been doing for nearly a year now.

Hi Amber,
thought I share my trailer pics with you. It isn't motorized yet; I use it for shopping at weekends, when finding a parkinglot for a car is a nightmare.
It will definitely not become a hub motor for a 16" wheel. A single reduction with a lowkV/low volt motor should do it.
IMHO a push trailer needs a throttle cutoff when the angle between trailer and bike is too big. Also smooth throttle control helps keeping balance in bends. Otherwise it'd be perfect for a trike...

Your trailer looks pretty massive, much better to add some kwh of battery there... but the point where it meets the bikeframe should be as low as possible, right?
Imagine a huge powerburst, wouldn't it almost lift up the rear wheel of the bike?


View attachment 1

olaf-lampe said:

It will definitely not become a hub motor for a 16" wheel. A single reduction with a lowkV/low volt motor should do it.

Click to expand...

That's probably a good solution for such a small wheel.

IMHO a push trailer needs a throttle cutoff when the angle between trailer and bike is too big. Also smooth throttle control helps keeping balance in bends. Otherwise it'd be perfect for a trike...

Click to expand...

Interesting idea; I may well borrow that. All I would need is a limiter switch on the hitch pivot on either side, like a microswitch with a roller on the switch and cams on the pivot, or a reed switch with magnets on the pivot, so the switch is closed when exceeding the limit. Hook the switch in parallel with the ebrake switch if regen is not used.

Or, if regen is needed then make the switch open when exceeded, and hook it up in parallel with the "controller enable" line.

Your trailer looks pretty massive, much better to add some kwh of battery there...

Click to expand...

It is kinda heavy, perhaps 20lbs already, but I already have this one, so it's an experiment.

but the point where it meets the bikeframe should be as low as possible, right?
Imagine a huge powerburst, wouldn't it almost lift up the rear wheel of the bike?

Click to expand...

That's my only real worry with this, and why I will be trying it with a simple hubmotor setup first, to see if it's safe to use this way.

The main reason I am trying it with this trailer first is simply because I already have it (just got from Freecycle yesterday). I'd prefer a BOB style like the one in your pics, as it keeps all the mass low to the ground, plus I could probably adapt all my trailers to work with that style hitch without too much modification (something I've been considering for a while).

Somehow I forgot to post this to the thread, but some months ago, a bit after the Undead Race, a cyclist friend came by to chat and I asked him to ride this unit while I rode The Velcro Eclipse (as a normal bike, no motor on it), so I could figure out if there would actually be any situations in which motor thrust applied thru the frame into the seatpost/tube of the bike would cause a problem. (as opposed to applying the thrust thru a lower point in the bike, like the rear dropouts or chainstays).

With him pedalling hard, it did cause problems in two situations:
--when turning sharply (fixable by putting an angle-cutoff as Olaf suggests above)
--when I'm trying to pedal the bike too, and I could feel the rear wheel slip sometimes, usually during his downstrokes, and usually at lower speeds, as the trailer's drivetrain only has one ratio (38:16 or something like that? I forget), plus it's smaller 24" wheel.

It did *not* happen if he leaned onto the bars when cranking, but if he stood on the cranks it would. I suppose leaning onto the bars puts enough of his weight (220lbs?) onto the bike's rear wheel to keep it fully on the ground.

So, yes, potentially this trailer could cause issues if I have enough weight on it to keep traction on it's tire to the road, no slip, and that weight is all at the rear wheel (which is pretty much exactly what I had planned for the batteries, though the cargo area would have been across it's top and forward parts of the sides, as there would be no cranks to leave clearance for, just the rear wheel of the bike in turns.