Theory of extended rear end for atv type swing arm to facilitate true & simple full suspension

So I was working on my build for the first time, day 1. As I was pulling the rear wheels off I noticed that very unfortunately my axle is slightly bent. I was pretty bummed about it but I didn't want to let that stop me and I happen to have a spare solid go-kart axle. I was thinking that I could just get some pillow bearings and mount them to the frame so I could just use that as my axle and use a CVT for my transmission. Would be fine but the V-Twin engine has a vertical shaft.. so I was thinking I could just cut down that transaxle to make it a 90° gear box.. then I thought, why don't I just leave it, put a swing arm on that transaxle where the wheels would normally go and run my axle on the end of that swing arm and extend the frame out over the swing arm. Just like a sports ATV. It would allow great rear suspension and would solve the issue of me not enough leg room as well as a much needed longer wheel base. What to you guys think? Did I explain my idea correctly? Let me know if you have questions.

I was thinking of something similar but just using tracks the size of the swing arm, like the tracks at the pivot on the swing arm would have no suspension but the free ends could go up & down.  Maybe a similar setup for the fronts but they would still steer.  Or add clutches and 1/2" drill drives to the fronts for tight spots.
I'm thinking of preventing back flips and climbing bigger obstacles more than adding speed or comfort.
Sticking to your idea, though, bicycle parts might adapt well to the task of power transmission and save the hassle of building or buying tracks. Everything adds weight though.

Dang it you! If I'm understanding you right, this is kind of the idea I've been planning for my mowers. I haven't said anything about it yet.

Anyway, if this is what I'm thinking it is, yeah I don't see any reason why it shouldn't work.

the idea is sound and as long as the drive sprocket and swing arm pivot are on the same shaft there should be no need for a tensioner sprocket, it would be something similar to cars and cameras monster truck go cart set up

That was my plan for my Broadmoor R/S build. It should work pretty nice if you did it that way really. I just planned on putting some pillow block bearings on the original transaxle, and making a swing arm of some type from there. Couple more pillow blocks on a straight go kart axle and connect them with a chain to drive it. Then you can put a disk brake setup on there or whatever too. Of course if you wanna chain drive it from one side only, you'll have to lock the diff. And as darkside said, if the drive chain is on the pivot point (transaxle axle) then you don't need a spring loaded tensioner or anything because the chain won't get any looser/tighter with the suspension movement. Although you'll still need some way to adjust the chain. Be that an idler or slotted holes for the pillow blocks somewhere to move the whole axle back.

Thanks you guys for the reinforcement of the idea. I'm glad to hear that some of you have had the same one.
@tour1 using that idea for tracks is a pretty cool one too. If you end up implementing it I would love to see the progress that you have.
@murraymountain I was thinking about not saying anything and having it be a surprise after I built it but I figured running it by you guys to see what you thought would be more valuable. I've never had a group like this for projects. If you get underway with this plan I'd be happy to collaborate.
@mr.modified @darkside0914 yes, that's exactly what I'm thinking. Forgot about still having to lock the rear differential.. with the use of pillow bearings and having the drive share the same as the pivot it will be nice not to have to incorporate some sort of tensioner. I like the idea of having slotted holes to adjust for chain tension and stretching over time.
There was this one video I saw by YouTuber titled rather be welding. He's working on an impressive go-kart buggy that incorporates this type of swing arm action but has two separate swing arms for each side with their own drive chains. this could also be incorporated into that build very easily. It would allow for independent suspension in the back.

This is what it would end up looking kind of like.

That's an interesting idea for independent rear. Makes it a bit more complicated but it's do-able. Well I guess it wouldn't even be that much more work. Only thing that you may have with that is some more twisting force if you still wanted to hook them on the original transaxle for a pivot. When you come off a bank sideways or something and the wheel has some side pressure, it would be sorta like having a really large diameter wheel on the stock axle because of how long the swing arm is. If you just have a solid rear, both sides would brace against each other. Kinda funny about 5 years ago, everyone on here was just starting to try front suspensions, now we're finally starting to get some rear suspensions going!

A peerless 700 would be a good choice to do the swing arm thing. A regular transaxle would work good too but keep the open diff if you plan on running chains to each rear wheels because if one wheel compresses then that force would be transferred to the other rear wheel through the chains and would probably snap the chains with a locked diff. When one wheel goes up, it spins and if the other wheel is planted to the ground then something will have to give by either the wheel going up is slipping or the force snaps the chain. I think rather be welding hasn't gotten that far yet. A single chain from a regular transaxle would be good if you lock the diff like mr.modified said with an atv swingarm setup. If I'm thinking right.

to me the independant setup would be something for desert style racing where you need to take big bumps/jumps at high speeds, it seems to be a lot more work than necessary for a tractor bombing through the woods, the solid axle swing arm would be more than adequate for that, and it's senseless, at least IMO, to have the independant rear if you don't have front suspension too,

The thing I think about with independent rear suspension on a Lawn Tractor is a recipe for trouble.  I could be wrong.  I would have to ponder about it more. 

Here's a video that might give you some more ideas.

That video Blake posted is very cool. Thanks for posting it! Quite similar to what I was thinking but the swing arm would ride at like a 30° angle instead of parallel to the frame. It was impressive how much extra traction he was able to get. When I'm done with my build I would like it to be able to drive more like a sports quad than a tractor.
That independent rear suspension is nifty but I agree that a single swing arm instead of two independent ones would be plenty sufficient, it wouldn't be too much more complicated to make them separate but I feel like starting out with making it as simple as possible and then later on making it more complicated is the way to go.

I think that independent rear suspension would definitely be cool! Would be pretty good at rock crawling and would also be a smooth ride. I guess my only concern would be cornering real fast but I'm sure you could get some pretty stiff shocks or even adjustable ones, then you could play around with spring rate and all that.

The independent swingarms would be really good at not high-centering because there’s no center to high HAHA!

I think the thing to remember is you don't need all that much travel to make a huge huge difference over  being solid. My front end on the simplicity has only about 2.5" of travel and that's a big help for 15mph or so over some pretty rough ground. Unless you really wanna tear over stuff at high speed out in the open, you don't need 6" of travel or anything. I think most of what we do in the woods ect is always gonna be somewhat slow speed because tractors aren't nearly as wide as atv's ect. Unless your gonna widen it way out.

Point being, it's a bit easier to make a suspension when your not trying to have a ton of travel. Just easier to make it all work.

That's a good point about not needing a ton of swing arm length and smaller is simpler. I want it to be simple. You guys bring up things that I didn't think about before and are really good to consider before getting into it too far. I also haven't decided what wheel size I'm going with and that will be factored into how long the arms need to be. I don't really plan to putter around the woods with this. I want it to be able compete with and in some cases outperform most sports quads. I'm going to be adding a topic specifically for the build soon. Is the front end of your simplicity A arms?

It’s a solid axle mono link with coilovers IIRC

murphyslaw wrote:

I don't really plan to putter around the woods with this. I want it to be able compete with and in some cases outperform most sports quads.

I've always thought about doing something like this and I think it would be something different and honestly more fun. I always thought it would be cool to have a tractor that had full suspension and alot of power, something you could jump, something that handles really well, and overall something you could just beat on and still be able to walk the next day!

Something like what grindhardplumingco on YouTube does with power wheels....but just on a mower. I know the only thing that would still be a mower would be the body but it's not any different than what they do.

basically you want to do something like this guy is
https://www.youtube.com/watch?v=KbMxYjoCa8I

darkside0914 wrote:

basically you want to do something like this guy is
https://www.youtube.com/watch?v=KbMxYjoCa8I

I've been watching that dude for a little while now myself.

Wow yes! That's an awesome build! A great place to draw inspiration from. I'm thinking something similar but 2x4 and no cv joints. It looks like the only stock parts on there are the body parts, at that point you might as well just build a custom utv/go kart. I'd like to incorporate a lot more stock parts.

@MightyRaze that thing is going to be a beast, personally i would have gone wider for the sake of stability, considering the power it's going to have and the high center of gravity, i think he'll find it difficult to handle well at speed

darkside0914 wrote:

basically you want to do something like this guy is
https://www.youtube.com/watch?v=KbMxYjoCa8I

Yes that's what I was thinking, just 2wd and alot more to scale....atleast in my head.

This got me thinking... If someone moved a transaxle forward, left it unlocked, and ran chains back to the suspended axle, it would be very impressive if they joined both sections with an electric clutch or something of that nature. That way you could get an electric locking differential. I won’t tell you how to build your machine, and I don’t know how well it would work because I’m still learning a lot about this but it would be cool to see it done! You certainly have a very clever idea!