Putting a swingarm on go kart

[Jeepracer427]

Im building a go kart for in the woods and want it to have suspension. it will be powered by a snowmobile motor. i know how to do the front but does anyone know how to put an atv swingarm on it?

 

[flaframer]

Hey, I am in the process of building one like that now. I had a junk
Chinese 200 atv that constantly threw the chain, along with a variety of other problems. Anyhow I cut the swing arm and the front end off of the frame and attached them to an old Murray Explorer frame. I cut the swing arm in half(from left to right) and added a section to it making it longer. I made mounts out of 1 inch angle and bolted the engine to the swing arm so everything moves independently of the rest of the frame, my welding skills aren't the best nor is my welder but so far so good.(with alot of grinding) I am using shocks off of a couple of old dirt bike swing arms so I think they are a bit stiff I will probably replace them with some softer ones in the future. I am almost to the point of needing to fabricate some controls( Throttle, front and rear brakes, clutch and shifter)

 

[Jeepracer427]

i may have to do that but i would really like the motor to be of the frame not the swingarm for what ill be goin through.

 

[flaframer]

Good luck getting the power to the wheels

 

[motor_head]

Good luck getting the power to the wheels

all you have to do is have a jackshaft in line with the swing arm pivot, so yeah good luck, probably won't need it since it's not very hard

 

[Doc Sprocket]

Piece of cake. Draw an imaginary line thru the swingarm pivots, and just make sure to locate the drive sprocket centered anywhere on that line. With everything properly squared up, chain will stay put.

 

[flaframer]

You guys seem to have it all figured out! You could probably also say you can make your own ocean one drop at a time, take a look at how almost all suspension karts are made(engine mounted to the swing arm) atvs are done the way you are explaining Captain Obvious. Keeping it simple is all I suggest.

 

[Doc Sprocket]

You guys seem to have it all figured out! .

Yeah, it's amazing what years of research will do for you!
As far as mounting the engine on the swingarm being very common- Yes. Because it's cheap and easy. But by no means the best or only solution. You'd be pretty hard pressed to find a motorcycle, quad, car, truck, etc set up with an unsuspended engine, even when it is chain drive.

We do know what we're talking about.

 

[flaframer]

I didn't realize this was an argument forum, I was merely sharing what is working for me on a project presently but you go ahead and finish saving the world from people like yourself.

 

[Jeepracer427]

i understand what yous are saying. does anyone have any pics of projects they have done to get ideas?

 

[psycho_builder]

i took the entire back half of a quad frame and put it into a gokart so i didnt need to build new mounts, but i also used the original quad motor as well, but it might be fairly easy to put the snowmobile motor into the quad fram then put the back half of the quad frame onto the go kart. but then again i dont kno how much you have to work with

 

[fowler]

what is meant by the imagaary line though the pivots is that the pivot to the axil or is it the pivot on the left to the right

 

[newrider3]

what is meant by the imagaary line though the pivots is that the pivot to the axil or is it the pivot on the left to the right

The imaginary line is the center axis of the shaft, like if you were to look at the jackshaft/engine pto from the end. You line up the shafts so they are on the same plane like this: ___ ___

I didn't realize this was an argument forum, I was merely sharing what is working for me on a project presently but you go ahead and finish saving the world from people like yourself.

Need to be a smarta$$ just because he actually knows what he is talking about?
The reason production karts stick the engine on the swingarm is to reduce production costs/time. This creates a bunch of unsprung weight, causing the suspension to be much less responsive and generally not work as well. By using some simple LOGIC and placing your jackshaft or engine output inline with the swingarm pivot (look at any good design such as the Dirt Devil or Edge Sidewinder) you have no chain issues.

 

[fowler]

the quad i got for parts bike had this set up

 

[newrider3]

Quads also have to run chain slider setups to deal with the change in tension throughout travel.

 

[flaframer]

Thank you for straightening me out by over-stating the obvious.
I too have seen, built, ridden and even raced atvs and dirtbikes.
I am very aware of geometry. pivots and axis' .There are pros and cons to either application, it boils down to a matter of opinion and amount of effort/labor one is willing to invest. Mounting the engine on the swing arm in my opinion is a good way of eliminating one variable of failure. When I said "good luck" I only meant o.k.,
have fun, hope everything works out..... and I was attacked by some motor-head who thinks he is Gods gift to engineering. I was under the impression this was a sight to share and glean knowledge and swap ideas but I suppose that could only be the case as long as one is very careful about how he words things.
Again Jeepracer427, "GOOD LUCK" with your project.

 

[Doc Sprocket]

I suppose many of us oughta watch how we phrase things. If you think backs aren't gonna go up when you say things like "you guys have got it all figured out" you're not paying much attention to your own phrasing.

We never said the unsprung engine wasn't doable, or even bad. He//, I'm using it on one of my karts to keep things simple. What was said, was that the better option was not as complex as you made it out to be. Then you got touchy. Whatever. Motorhead? Yeah. Nobody "attacked" you.

Now- This forum is an excellent means of asking and answering questions, sharing ideas, and batting theories around. There will be differing opinions, and ultimately an argument is simply the weighing out of opposing opinions. So-
Keep the attitudes in check, and this is not a problem- right?

ANYHOW- As stated, having the engine mounted to the swingarm is the simplest, cheapest way of having rear suspension on a kart, and does it's job decently enough. BUT-
(WARNING-argument here!) For many reasons, it is preferable to have the engine suspended along with the chassis, independant of the rear axle's travel. It usually (but doesn't have to) require a jackshaft which induces additional cost and weight, but many of us use jackshafts for other reasons anyhow, such as the use of a CVT or torque converter. Ultimately, with a small investment in time, money, and thought, you get a lighter, more responsive suspension, and your engine gets a much cushier ride while you bash the he// out of things offroad.

Think we can all make nice, now?

Jeepracer, if you toss up some pics, it'll help us point you in the right direction..

 

[flaframer]

Thanks for the more congenial reply however I never insinuated anything , it was a vague, generic comment at most and I was attacked for it, I agree I could have and should have been more specific. I have personally built both ways and with the use of jack-shafts, The assumption was made by motorhead and it seems everyone else was in support of him. I don't believe he was around when independent suspension was invented but I on the other hand wasn't far from it HAHA(reference to my age) Once again I will be way more specific with my comments and I never said anything was impossible I am only stating from experience that I have had that mounting to the swing arm has never presented a problem to "ME"

 

[Jeepracer427]

http://www.facebook.com/album.php?a...ved#!/photo.php?pid=317998&id=100000143872936 i couldnt find any other way of uploading it

 

[motor_head]

yeah maybe i went a little overboard but i get tired of people telling everybody that mounting the motor on the swingarm is the only way to do it