LesterOfPuppets

I started thinking about this long ago, but it's been on the back burner. I just got my bed put together, so thought I'd post what I have. Perhaps that will encourage me to keep moving on it. Parts needed: BMX size quill stem. Shock. Hoping to find a kids bike with shock at the SA today, but no luck.

I'll be using a rack with an approx 22.2mm ID tube attached as a receiver.

Side View:



View from above:

AdamDZ

Are you sure that's a good idea? You're gonna have to really balance your load on it or it'll be twisting the hookup mechanism like crazy, no? I'd go with two wheels with such a wide frame.

Adam

LesterOfPuppets

Only time will tell. My hitch system seemed to handle twisting for my lowboy two wheel just fine. Of course that is a little different. In that case you have the trailer remaining horizontal while the bike leans into turns. It consisted of a skateboard truck elastomer and king pin attaching the 1" pipe tongue to a rear rack. This insulated the leaning of the bike from the horizontal trailer quite well. For a one wheel trailer there will be a chance of some harmonic whipping of the trailer with this setup, so I've also considered one inch tubing bent into an S shape and trying to source or devise a cheaper, 1" version of a 90 degree fixed coupler connected to the seat post.

I'll have to do some mulling to see if the one inch tubing could handle the twisting forces, it's fairly thick wall, so I think it could.

LesterOfPuppets

I may very well have to reduce the size to just one of those frames. That would give the bed more BOB-like dimensions of 20x24".

crazzywolfie

i don't think i a trailer with a bed like that would work good on 1 wheel. i have managed to roll my trailer and it has 2 wheels. all it takes is a not so balance load and 1 good pot hole or bump.

AdamDZ

That's very different. Here you will have the loaded trailer twisting, it will most likely result in a lot of forces on the hitch. The hitch will be responsible for holding the trailer straight and I bet you will feel it when riding. Even if you have a dual point attachment like BOB does, I'm afraid this will result in unstable ride and damage to the hitch.

On top of that your center of gravity is very high. The reason BOB has a wheel behind the main basket is so the basket can be low to increase stability. Putting a single wheel under a wide platform is not a good idea IMHO. Seriously, think it over, before putting more work into it. Perhaps put the wheel behind the frame, so you can bring the frame lower to the ground, BOB style?

LesterOfPuppets

I've seen some high COG car and motorcycle single wheel trailers. Most of the car ones are different as their wheel is castered. I'll have to look more closely at the hitch mounts for MC ones to see how they account for the high COG.

The biggest problem I'm seeing is that a single wheel trailer can't be allowed to roll in relation to the bike (or at least roll very little) or the trailer will flip as per Wolfie's concern. Because of this it seems like a high-mounted hitch would be terrible as then there's a lever between rear wheel contact and the hitch point. The bigger that lever is, the worse off I envision things, so I'm thinking no-go on the seatpost connection. I'm not looking forward to the rear dropout connection point. That would require either a tandem skewer $15 is the cheapest I've seen, or some other machine work.

More mulling will surely be done. I don't mind setting this one up to have it fail as long as material costs are kept low. So far materials are less than $5. Add about $6 if you count the opportunity cost of recycling the aluminum frames I'm using.

If it doesn't work, it will not take long to make a 20x24" BOB clone should I decide to splurge on the tandem skewer.