Let me preface this by stating I'm not a traditional Harley owner, I received the bike as a gift years ago, I haven't taken the best care of it just because I haven't had the money to spend on it and while there's nothing wrong with it I'm far from a Harley purest, as far as I'm concerned it's just a form of transportation with a cult following. I have a 2001 Harley Dyna Wide Glide, 33k miles and hasn't been ridden in maybe a year or so. I don't drive my personal vehicle much because I work on the road from sunday to friday and my work is 15 or so minutes up the road. Now I use to use my F250 to do this task but honestly with the little amount I drive I'm honestly not really feeling like keeping insurance on the truck where my bike insurance is 75 a year. Now when I get off my wife tends to ask me to go get odds and ends from the store including 45lb bags of dog food, canned sodas, dinner items, etc in a truck this is no big deal but on a bike it's just not doable. I'm not interested in doing anything permanent, even though my attachment to the bike is limited to basic respect for the person who gifted it to me I prefer to not make any permanent modifications that I can't undo. Now I've always envied how developing counties utilize low cc bikes that are purpose built with truck or flatbeds to accomplish work.

I've always found those little carry-abouts interesting but considering my financial situations I couldn't see myself buying something that would be to slow for my rural community and most likely poorly made. I'm considering doing a conversion on my bike, something bolt on, taking a inexpensive trailer frame, cutting off the tongue and welding up a series of mounts to bolt it to the frame of my current bike similar to a trike but with a flat bed with or without folding walls and still retaining the rear tire to apply power to the road. Obviously weight would be a major concern so a electric or additional brake cylinder to the foot brake assembly to operate the additional axle brakes (most likely not reasonable due to the lack of a booster), I also don't want to add a tremendous amount of weight to the rear tire so I'm considering incorporating some form of weight distributing system to shift the weight of the trailer/cargo onto the front tire/flatbed axle. I have no concern about the engines capacity to handle the extra weight, the handling would definitely be different due to the inability to lean due to the fixed design I'm just wondering if the addition of dedicated brakes and weight distributing design would make this concept feasible. I don't care about purest mentality, I'm looking at it from the perspective of increasing the utility capability of a form of transportation I already own through.

 

Why not build a trailer hitch and use trailer a small flat bed 40x48 trailer? Fewer modifications to the bike. The trailer suspension will allow more cargo load.

I have pulled cargo trailers for many reasons behind my bike. The heaviest was when I was loaded down with beer and liquor! I had 12 cases of beer, and 7 handles of liquor.

 

Your insurance is $75 a year? Trailer would probably be easiest. A real flatbed trike would be interesting but a project.

As for dog food, I know what you mean.

Maybe passenger back rest with sadd to e bags to lay on top of or saddle bag guards that go behind saddle bags for attaching small platform.

If money is the reason I just don't see this being best way to save money and working out as great as you think.