I’ve been putting together this Chinese bike engine kit I got off eBay on a Shwinn Swindler. It seems like it’d be an easy project but it has been hell and a money pit, and it doesn’t even work yet.
Long story short I don’t have the chain that came with the kit anymore so I went to my local power sports store and bought two off old ATVs, put them together at the perfect length then had them break on me today. That’s what you get for using two master links. I’ve had to file the frame and fenders because the chain rubs against them everywhere it can. The coaster brake arm does not like being on the second sprocket, as seen in the photos. It’s been causing the wheel to not spin as freely. The chain tensioner broke half off. Total money spent on chains: 80$. This is the third chain I’ve had, although the other two wouldn’t fit. The engine runs, just not for long. It will usually quickly roll to a stop, sounds like it loses power all of the sudden.
What I need to do now is get a new chain and create my own tensioner. Does anyone know what the measurement for that chain would be? There’s stuff like 410 and 415 I don’t know what that means. There’s a photo of the chain I put up.
Looks like you’re trying to kludgy this together. The chain would need to be inside the left chainstay at the rear, but outside of it at the front. That in & of itself isn’t a big deal, but the crank is also outside of the chainstay. I’m thinking if you try to pedal at all that the two would try to occupy the same space.
The silver colored vertical piece with three nuts on it that is mounted to the chainstay; does the bottom of the chain come up over what looks like a roller on the top of it? In which case the top & bottom of the chain would be very close together.
It’s hard to tell from the picture but how big is that chain, is it much wider than a standard bicycle chain? If not, go to your LBS (Local Bike Shop) & ask them to help. Any decent mechanic would easily be able to adjust chain length for you.
The bottom part of the chain sits on top of the roller, that vertical thing in the picture. I don’t really know what your first paragraph means with cranks and stuff. The bike functioned, until a chain roller got caught on either the fender or chainstay, and one of the two master links bent and snapped. The chain is thicker in general than a regular bike chain, closer to a motorcycle chain. I’ve called around to a few “bike” shops around here, they avoid motorized cycles like the plague. I’ll keep calling…
BTW, the master link visible in the first pic is backward I believe. On all my dirt bikes the closed end points the other way - towards the direction of travel.
And when I have replaced chains I always do it the same way.
In the direction you have it, when the chain is rubbing as you say it is, that will be trying to pull it apart.
There’s a range of chains… did you match the motors gear to the wheel gear ? Did you get them as a set ? maybe they are mismatch… Or maybe the chain isn’t the match to them.
You need all gears to match the chain …
In that picture I just set the chain on the sprocket for getting it into the photo. When it came off, the closed end was facing direction of travel
That’s what weird. The space between the sprocket on the engine is different from the space on the rear wheel sprocket, causing some chains, like a regular bike chain, to not fit properly. These two chains I spliced together, that both came off ATVs/dirtbikes, fit in the teeth fine. I’m not sure if that’s normal but if I have to change out the sprockets thats fine.
In this photo album I’ve included pics of the two chains next to eachother, the engine side chain being the larger one, the one on the left side (photo got flipped upside down), as well as (low quality) photos of each sprocket. In the last photo if you can look closely you can see the alignment of the two.
You need to cut your losses and move on this project is a clunky boondoggle and is going to chew up far more money and time than the result will be worth. These components are not well matched to each other and you do not have the machining or mechanical skills to correct these issues. Buying more parts will not solve this problem.
If you’re considering abandoning the project and starting another one, allow me to put in my $0.02 and suggest an electric motor instead of gasoline.
Here in Oregon, if you put a 49cc motor on a bicycle, it becomes a moped and you’re required to have fenders, lights, turn signals, a lighted license plate (and yes you have to register it) plus you need insurance and a DOT-approved helmet. And that’s if its top speed is less than 30mph. If it will go faster than 30, then you have to register it as a motorcycle and do all of the above plus get a motorcycle endorsement on your license. If it’s a 33cc motor, then you can call it a motorized scooter which doesn’t need to be registered but you are prohibited from ever riding it faster than 12 mph and you can’t use it on any street where the speed limit is higher than 25 and most cities won’t allow it on the bike path and if you ride it on the sidewalk you’re required to slow down to “ordinary walking speed” when you approach a driveway or intersection.
OTOH, if you use an electric motor, up to 1000W, and the top speed is less than 20mph without pedaling, then you can ride it anywhere that you can ride a bicycle, on just about any street, but you still can’t engage the motor when you’re on the bike path.
If the electric motor (without pedaling) pushes the bike faster than 30mph it’s a motorcycle, or if it tops out between 21 and 29 then it’s a moped, same as a gasoline bike. But if your goal is to cruise at 15-20 mph then you can do that legally with an electric motor but not with a gasoline motor (unless you register it as a moped). Of course, the laws in your state may be different. And none of this applies if you ride strictly off-road.
Also, electric motors are quieter and don’t emit noxious fumes.
