Polaris ATV gets a new Rollcage Chassis

rea2112 · #1 03-01-2007, 12:41 PM

Hi Everyone,

This is the start of my 1st Chassis build. I'm new to fabrication and just picked up welding last August. I had a need to better protect myself when riding my 05' Polaris Sportsman 700 EFI. I wanted a wider footprint as well becuase I ride a lot of off camber trails in the Rockies. Having a chassis with a roll cage seemed to be the way to go. Only fear now is if I drive off a cliff I can't bail as I'm strapped in. I guess if this happens then I get to check how well my welds hold up.

I tore down my ATV to the chassis last October. I've had Bend-Tech Pro since January 07'. I'll start with a pix of the design in BT-Pro. I have already to date, completed 90% of the chassis.
Follow me along as I have 1 month to get everything back inside the new frame. Oh, Specs. My ATV was 4' wide and 6' long. Now it will be 5' wide and 8' long. Dimensions are from tires outside edge. The origianl frame weighed 90lbs. The new one so far is spec'd for 143lbs using 1.5x.095 DOM A513 steel. BT-Pro calls for 119' of tube. I think it'll have another 15' by the time I'm done. Feel free to add thoughts or comments.

Marvin

rea2112 · #2 03-01-2007, 12:54 PM

Here are a couple more pix. I started with the center section and wanted to get the cage out of the way so when I add the bottom I wouldn't have to work so high up on the table if I added the cage last.
The design came from viewing other projects, magazines of Rock Crawlers and sandrails and I did buy the Badlands ST2 plans so I had dimensions to go off of. I then modified the design to fit my needs. Note how the back end remains wide instead of tapering in like most buggies. I did this to accomodate the Cargo box that was on my ATV. It's very handy and since I'm losing my front storage area I figured I'd better incorporate some way to get the tools, lunches, cameras around.

Marvin

rea2112 · #3 03-01-2007, 01:53 PM

Here's 4 more pix. I finished the bottom section not counting the 2 front legs that bend up to touch the front upper section.
I tried using 4 blocks of wood to hold the middle section up while I fit 2 tubes to the back end. This didn't do well at all since I didn't fasten the blocks to the table. I went ahead and tacked the 2 tubes to the back section at the bottom only and this allowed me to place the top section on those 2 tubes then I could use the 2 blocks up front. I eventually tossed the blocks and just hung the front section. Took hours to get the top section and bottom section perfectly lined up.As long as I didn't tack the top of the rear tube I could raise/lower the front upper section to my liking.
Note one of the pix has the rear diff, tranny and seat mocked up. I'm getting worried that I'll have to place my seat further forward then where I was hoping to have it. As you can see there won't be much room for my feet. I've sat in the seat and I can make it work. The only think going upfront is the front Diff, Tierods which should be mounted higher then 8' from the bottom and steering which will be between my feet. I'll have a brake pedal to the left of the front driveshaft and a gas pedal to the right of the shaft. The Winch can be mounted as high up as I can get it and as far forward as possible. One thought was to add more tubes to the top front section which will tie in with the front most cage hoop. This will allow the front section to be taller and I can have more room for the winch. I'll wait till I add the front components to make that decision.
The last pix shows the top and bottom section mated together. This is a chassis 80-90% complete as far a tubing. I still need the tubes for Control Arm support, Trianglation on the sides and possible support for the bottom center section. I also want to Gusset as much as possible cause my welds are not as great as they should be.

Marvin

russellmn · #4 03-01-2007, 02:46 PM

That's looking pretty good. I like the basic layout of it, looking forward to seeing more.

SlightlyModified · #5 03-01-2007, 05:41 PM

I like the idea, some day I may do this to my 05' Honda Rincon. I'll be looking for more progress pics, great job so far.

nutnbolt2002 · #6 03-04-2007, 01:29 AM

It's looking great, I noticed is there any way you can shorten the drive shaft to the rear diff?

rea2112 · #7 03-04-2007, 05:36 PM

Quote:

Originally Posted by nutnbolt2002

It's looking great, I noticed is there any way you can shorten the drive shaft to the rear diff?

The shaft of the rear diff is about 3-4" long. Most of what you see there is the 2 U-joints. I guess I could if I could line up the Tranny and read Diff perfectly then I wouldn't have the need for U-joints. However I'd have to find some type of adapter that will convert Splines to a smooth female end.
The other problem would be with moving the engine back a few inches is I think it would hit the rear most Hoop so that would have to me modified or moved. The Engine will sit atop of the Tranny. I'll give it some further thought!

Thanks,
Marvin

nutnbolt2002 · #8 03-04-2007, 08:20 PM

I was just thinking that it would give you more room for the seat.

therail · #9 03-04-2007, 09:50 PM

I dont get why you need a rollcage a on Sportsman 700. The idea is to hop off the quad if you think something bad is gonna happen.

rea2112 · #10 03-07-2007, 12:13 AM

Quote:

Originally Posted by therail

I dont get why you need a rollcage a on Sportsman 700. The idea is to hop off the quad if you think something bad is gonna happen.

You would think you would know when to jump off. I thought about it often while riding and thought, "Hey if something happens just be ready to bail".
Last winter I was riding my ATV on a trail heading down a moderate slope that was icy in spots. I thought I was under control then Wham! out of no where my ATV turned sideways with me in front then it rolled over on its side pinning 1 leg underneath the ATV. The 700 is 800lbs. dry and nobody was around to help me. Luckily I had a free leg and was able to free myself after 1 minute and luckily I didn't break my leg but I have a nasty scar from it.
I went over the accident a thousand times within the first 24 hours and I didn't know why I didn't see it coming. It just happened!
That's when this idea popped into my head to have something a little safer. Besides I like building stuff and thought this would be a great project.
The next ride will be a bigger machine and bigger chassis.

Marvin

rea2112 · #11 03-07-2007, 12:25 AM

Since I lasted posted pix I've added trianglation and the Diff brackets.
Also have the Engine hanging in its proper place.
So here are pix of 2 brackets I fabed using only a 4.5" cutoff wheel on a hand grinder and a drill press. I can't believe it took me 3.5 hours just for these 2 pieces. They are only tacked in place in case I had to move them. Now I'm thinking there is no way I'm gonna be done by the end of March.....Maybe March 2008

Marvin

rea2112 · #12 03-07-2007, 12:35 AM

I have the Triangulated pieces in place but still need to be fully welded.
So I got the engine mocked up tonight and that took a couple of hours to get it level and at the right height. Lot's of variables here because I have to make sure the CVT belt will be properly aligned from Engine to Tranny.
I bought an aftermarket belt because I needed to place the 2 pulleys 1 inch apart over stock. I have a tool from Polaris that will help me align the pulleys. I verified that I can get to the Engine Oil drain plug.
The engine is sitting higher then I expected. I was hoping for more room on top because I was wanting to put the radiator just underneath the 2 straight support tubes from hoop2 to hoop3(furthest back). I didn't want to have the rad on top of the tubes as the rad could get crushed in a rollover.
I'm trying to keep everything inside the cage for that reason.
Hope to have the engine and tranny mounts done by Thursday night.

Marvin

JoshC · #13 03-07-2007, 08:30 AM

I'm kind of like the last guy who wondered why you need a roll cage on an ATV, but i like it so far, looking forward to more pics!!

therail · #14 03-07-2007, 12:50 PM

Thats a pretty crazy story. Fab work looks nice though. gonna put a winch on it? I dont think it will be very easy to man handle.

jamiez71 · #15 03-07-2007, 02:16 PM

I like the way it's looking so far. Looks like you've got some time in designing your layout also. Looking forward to seeing the pictures. Josh that's what I needed on mine when I rolled my atv off the waterfall 2 weeks ago.

shaggy10000 · #16 03-08-2007, 02:27 AM

Quote:

Originally Posted by rea2112

You would think you would know when to jump off. I thought about it often while riding and thought, "Hey if something happens just be ready to bail".
Last winter I was riding my ATV on a trail heading down a moderate slope that was icy in spots. I thought I was under control then Wham! out of no where my ATV turned sideways with me in front then it rolled over on its side pinning 1 leg underneath the ATV. The 700 is 800lbs. dry and nobody was around to help me. Luckily I had a free leg and was able to free myself after 1 minute and luckily I didn't break my leg but I have a nasty scar from it.
I went over the accident a thousand times within the first 24 hours and I didn't know why I didn't see it coming. It just happened!
That's when this idea popped into my head to have something a little safer. Besides I like building stuff and thought this would be a great project.
The next ride will be a bigger machine and bigger chassis.

Marvin

I completely understand the cage idea. I have a friend who went through the same thing. A couple of them were out riding and for some unknown reason he slid sideways and flipped. When the quad came down it landed on his head, slid for a while, fell off and he continued to slide about 12' further. They gave him a 20% chance of survival and a 0% chance of making it back completely. Then after a week in icu they had his mom come down and sign some paperwork because they didnt think he was going to make it. Anyway long story short he has made about a 95% recovery and is now back to work, able to drive and do most things like he did before. He just forgets alot now and has a slight slurr in his speech. Of course like most of us youngsters we dont wear a helmet and drive like crazy. Kudos on the idea from a fab standpoint im the same way i love to do stuff like this just because i can. keep up the good work.

nutnbolt2002 · #17 03-08-2007, 11:05 AM

Are you going to use the Polaris rear suspension, and the macpherson struts on the front?

SlightlyModified · #18 03-10-2007, 09:56 AM

please say your not using the struts on the front. It seems that would be a poor design. I can't believe polaris sells atv's with the front suspension they use. I like the looks of things so far. Keep up the good work. is anyone else helping you?? I've always got 10 friends who say they will help with a project, and rarely does one show up.

JoshC · #19 03-10-2007, 10:09 AM

Quote:

Originally Posted by SlightlyModified

I've always got 10 friends who say they will help with a project, and rarely does one show up.

Hey at least you have 10 friends

rea2112 · #20 03-13-2007, 10:11 AM

For some reason I'm not getting email notifications anymore when you guys post. So I didn't know I had questions to answer. I also need to get more pix posted. Let's see.

I don't have any friends that are willing to help except for 1 but he hasn't come over yet. So it's a solo project.

Yes I will be using the complete Poalris Suspension. I'm not kean on the strut either but I was trying to keep this project in check financially, hence why I'm trying to reuse everything I can. I know I'll lose articulation but this is my first project so I didn't want to bite off more then I could chew. The next project will definitely have controls arms all the way around Plus it'll probably be homegrown A-arms so they'll be longer and I'll get more articulation.

Engine and tranny are now mounted and front diff is mounted and I already got an a$$ chewing for fab'ing my own front driveshaft. I'll have to wait and see if I get chattering teeth when I run this ride. Just hoping for the best.
Pix will be posted tonight.

Marvin