Tiny single-wheel for scooter

[hobolurkin]

Does anyone have any basic ideas to get me on the road to building a super-tiny trailer to tow behind my scooter? I just need it to be able to haul the basic camping supplies at a peak speed of 70kmh / 43mph, and sustained speeds of ~60kmh / 37mph.

I know this might sound dumb for trying to start a project like this, but I can't weld

What are the minimum basic bolt and steel strengths that I should use?

I was thinking about a frame and wheel that goes together like this ... http://pg.photos.yahoo.com/ph/btaillon2001/detail?.dir=/c2dc&.dnm=9dff.jpg ....

and hoping to make a deisgn similar to this in size and shape ...


Is this do-able without welding?

Thanks!
Bart

[angib]

Is this do-able without welding?

I think that's a tall order. Something like 2"x2"x1/8" angle (or maybe 1.5"x1.5") could be used to make the frame and swing arm just like in the photos and it might even be possible to make the frame so it bolted together, but bolting the suspension together isn't really practical.

If you used a standard rubber torsion half-axle and wheel/hub (like the Northern Tool one shown below), it would be much simpler to make, though rather ugly, as the suspension would have to stick out on one side of the wheel.



But you cannot buy a hitch for this sort of trailer - you have to make it yourself. In case it's not obvious, the hitch has to provide freedom to rotate up-down (for suspension) and left-right (for steering), but not to allow twisting so that the trailer doesn't fall over. Using a universal (transmission) joint from a car, like in the photos, is a neat way to achieve this, but it is likely to need not just welding but some machine shop work too.

Finally you have to make the tow bar that connects the hitch to the back of your scooter. Once again, doing this without welding ain't easy.

So I think the answer is a 'no'. And, at the risk of being a bit rude, if you need to ask what parts to use, you probably should ask yourself whether you have the necessary skills to build this sort of trailer - for example, it would be a lot easier to build a complete teardrop trailer as seen in this forum than this much smaller trailer.

But if you can prove me wrong, I'll be delighted and will look forward to seeing the photos!

Andrew

[surveytech]

Andrew,
do you think it would be easier to build if it had two wheels and a standard tongue?
Couldnt you just build it really really small then?

Walter

[Elumia]

sounds like better suited to bicycle components. Lots of mountain bikes have suspensions. Also a hitch mechanism along the lines of those add on tag along bikes might work as well.

This BOB bike trailer has a suspension
http://www.bobtrailers.com/trailers/ibex.php

[angib]

do you think it would be easier to build if it had two wheels and a standard tongue?

Yes, that would enable the trailer to be made from standard parts, like the same suspension and a standard hitch. I could then see how to make a bolt-together trailer frame that would work, but building the hitch remains somewhat tricky and very difficult without welding.

Andrew

[Laredo]

The image below comes from a really good page about exactly this type project, but IMHO would be easier to build than a single-wheel.

Bear in mind you could use a lighter-duty trailer.



http://www.gadgetjq.com/trailer.htm

[Cruiser]

Actually,,, one thig that comes to mind is a motorcycle swingarm. If you have a MC junk yard near you, or can find a doner moped or small dirt bike. You could use the swingarm and rear shocks/or shocks. The dirtbikes usually have single shocks. Oh, and I like the pics of your progress. But you might want to make a bridge/ladder type support ans thats a long span.
Good luck
Steve Cruise

[Paw_Paw_Drew]

I once had a small one wheel trailer that hooked directly to the bumper. The wheel would swivel for turns. Perhaps something like that would work if you didn't mind a drawbar on each side of the bike

[angib]

Anyone interested in single wheel trailers, and willing to see a whole day disappear with no idea where it went, should visit Single Wheel.

Andrew

[Chris C]

You're right, Andrew. I just went to that site, and could get lost, that's for sure. Thanks for the link. It'll be fun to browse.......................some day when I have more time.

[surveytech]

how about this single wheel teardrop?

[Gambam]

here is a cool pict of the frame of one of those.

Like said above, you could look for an old mini bike frame or another scooter. You will prob have to have some one weld up a tonge for you.

[brian_bp]

There is a middle ground between the jack-of-all-trades welder/fabricator/trailer builder, and the extreme of needing to bolt everything together: fabricate and fit the pieces yourself, and take them to a professional for welding. That is how I did the roll cage in my race car.

The scooter and trailer pictured in the first post look great - I can see how you would want to copy that. The BOB bike trailer is functionally the same thing.

I do have a couple of concerns with single-wheel trailers:

The type which have non-castering wheels and hitches which pivot for steering should be stable, but could make the scooter difficult to handle - think of adding the entire trailer weight on to the scooter, then trying to balance it at low speeds... I think that the key is to keep the mass low (meaning both light and close to the ground).

The type which attach to the back of the vehicle with only one (horizontal) hinge axis, and use a caster (like those which seem to be the focus of SingleWheel.com) are inherently unsound. All of the cornering force and directional control comes from the tow vehicle (tug), but the trailer adds a significant mass way out behind the back. When you turn, the trailer is trying to rotate the tug further into the turn, and the tug's rear wheel is doomed to have insufficient traction for the job it needs to do. You can get away with this if the trailer is very small (in mass and length) compared to the tug, but a travel trailer on a small car or scooter is another matter. I think the other design of single-wheel is better.

A more conventional two-wheel (two-track) trailer is easier to make work, with two considerations for motorcycles:

• the hitch must rotate freely much more in the leaning directions than for a car
• the tug is narrow, and if the trailer is made very narrow to match, the wheels won't be very far apart (the track width) so it will be very much affected by one-wheel bumps.

[mwatters]

I've been riding bikes since I was about 12 (on the road for nearly 15 years, all on bikes under 500cc). Been towing trailers (NOT with bikes) for much less time - about 5 years. I would NOT present myself as an expert on either - just a guy with modest experience.

My overall feeling is that bikes and trailers don't mix. Yes - I know people with big bikes pull little trailers. But if you've ever had a little trailer start to sway on you, you'd know why I feel that way. It's bad enough in a significant tow vehicle - sway behind a bike is gonna bring you down.

That being said - I would say that an honest answer is going to depend strongly on your intended useage. If it's for hauling small amounts of items short distances - I'd say to go as lightweight as possible - build as if you were going to pull behind a bicycle and go for it. Possibly converting either a bicycle trailer OR one of the little 'trailers' that a child is supposed to ride on (looks like the back half of a bike).

For riding any serious distance at any serious speed - I'd honestly suggest adding luggage capacity to the bike itself. Soft-sided saddlebags (intended for bicycles or sportbikes) look decent on scooters. Hard plastic trunks can be bolted onto rear racks, additional racks can be added to the top of the trunk, and if you have a back seat, luggage can be bungied on the passenger seat (giving you a backrest too!).

It's not nearly as cool looking as a little trailer - but you can hold about as much and it's much safer IMHO.

Mike
Watters

[angib]

And to present a counterpoint to Mike's comments, here is the world record holder for towing a motorcycle trailer - 139mph:



Interestingly they put 35kg (77lb) of ballast into the 50kg (110lb) trailer for the record.

Andrew