First build: step through bike and big bike trailer.

I finally bought a bicycle engine after having a casual interest in getting one forever.

I mounted it on a step through bike I had laying around, which presented some problems. Mainly gas tank position. So I welded a piece of pipe on the frame to mount the tank. I also welded the tank mounting brackets to the pipe, since the fit was kinda loose. I welded the engine mounting outer brackets too. I read that you may want to adjust the tensioner position later so I just tacked it in place. I just used the cheapest hazard fraught flux core welder. I dont have much practice welding, so my welds are pretty ugly.

So I wanted my wife and toddler to be able to ride too, and since I dont have the budget to set up a second bike currently, so I built a small cart to tow. It's way heavier than it needs to be, but it works. I welded a post out to one side of the rear wheel frame and welded a pipe coupler on that. Then I used a spare tractor pin to attach them. Everything was built using scrap laying around. It's a work in progress of course.

Eventually I want to put the engine into a wooden go kart, and add a couple gear ratios with v belts and tensioners.

 

[Chainlube]

Welcome to motored bikes, you never want to weld your chain guide, chains stretch and need periodic adjustment.

 

[mark20]

welcome to the forum!

like chain said, dont weld the adjuster as the chain stretches a LOT, also reinforce those fenders as they tend to snap off (and lock up your front wheel, and then a trip to the ER)
im not sure that you might be able to pull a trailer without gearing it up some more, (ie bigger rear sprocket)

other than that it looks like its going to be a lot of fun!

 

[zimirken]

The trailer is hard to get started on the dirt driveway, but I got a pull start and the engine gets it going just fine. Once I'm on the road it's fine. I would like a little bigger sprocket though.

I just did a little tack on the tensioner, so when I need to adjust it I just hit the grinder a sec and I can move it.

 

[mark20]

The trailer is hard to get started on the dirt driveway, but I got a pull start and the engine gets it going just fine. Once I'm on the road it's fine. I would like a little bigger sprocket though.

I just did a little tack on the tensioner, so when I need to adjust it I just hit the grinder a sec and I can move it.

Alright.
Also please reinforce those fenders with some L brackets. As the stock ones are too thin and will snap at the worst possible time (happened to me, glad i was only going about 8mph)
L brackets are like 1.48$ a piece. Its a lot better than making a sweet trip to a sour one

 

[Chainlube]

I was just looking at your little trailer, you can make it a lot sturdier if you screw a couple of pieces of wood (plywood or 2 bys) to the sides of the hitch pieces. They look like they would rattle apart with much use.