Long John project

[fpavao]

Has anyone build something like a long john/ bakfiets/ box cargo bike?

I have a client who wants something like a Bullit, but it's not available here in Brazil. We're thinking about doing a prototype, perhaps in mild steel, and then go on to a final version in straight gauge 4130.

I'm not sure how to proceed regarding the back bone of the frame: one large beam, two beams, space frame with small diameter tubing? Any input on this? I'm greatly in favor of a single beam, mainly because of welding time and the fact that I don't have a jig to hold the tubes (not for now at least).

I'd use fillet brazing (I know, terrible idea) as I don't know how to tig weld, but for the final version tig welding could be arranged with a local welder.

Thanks!

[cp43]

I don't have any specific info, but Waltworks did something similar:

Waltworks Bicycles: Sick day #5 - Cargo Bike!

There might be enough on his blog to answer some of your questions.

Chris

[fpavao]

Thanks Chris for the link and Walt for the blog.

This past weekend I brazed some tubes on an old mtb frame to see what I got. I won't post any pictures because it looks terrible, but bottom line is, the thing works. It feels very awkward to ride compared to a normal bike, and almost impossible to turn around on small spaces.

About the steering system, anyone got recomendations? On my weekend prototype I just strapped some brake cables on the fork and steerer, it seems it would work fine if properly done, but haven't figured out how to make it turn 90 degrees yet.

Maybe a pushrod would be better, despite the little extra weight.

[mbeardsl]

Walt's pretty open from my experience, I'd give him a call or shoot an email. He may even have better sources for you to talk to.