Dismiss Notice

Welcome To CK5!

Registering is free and easy! Hope to see you on the forums soon.

Score a FREE t-shirt and membership sticker when you sign up for a Premium Membership and choose the recurring plan.

Tubing diameter for rollcages

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by Mudfreak, Dec 24, 2001.

  1. Mudfreak

    Mudfreak 1/2 ton status

    Joined:
    Dec 16, 2000
    Posts:
    116
    Likes Received:
    0
    Location:
    NY
    I wanted to ask those of you who have rollcages, what diameter metal tubing you used? Also how it is for passengers to get in and out through the doors to the rear seats?

    88 K5... work in progress
     
  2. DesertDueler

    DesertDueler 1/2 ton status

    Joined:
    May 23, 2001
    Posts:
    3,106
    Likes Received:
    0
    Location:
    Phoenix, AZ
    I use 1 and 3/4 in the Jimmy and 1 and 5/8s in the Firebird. I have the doorbars on the Jimmy so its easy to get in and out. They are about 3-4" above the floor. As for the Firebird they are setup for NHRA specs so if you dont know how to get in and out it can be kinda tricky. Once you learn its really easy though. BTW both vehicles have full cages. The Firebird one is legal for 7.50 1/4 mile, and the Jimmy is a family style cage similar to a safari cage.

    86Jimmy 4"&35"MTRs,87 burb 4"&33"MT,69Firebird w/525 hp,and 70GTO live in PHX,AZ<a target="_blank" href=http://www.geocities.com/modifierperformance>My vehicles</a>
     
  3. Michael

    Michael 1/2 ton status

    Joined:
    Feb 17, 2000
    Posts:
    1,576
    Likes Received:
    0
    Location:
    Sherman, Texas
    I also used 1.75" tubing....works great for me, I personaly don't like the looks of the larger stuff and it takes up more room. Just depends on how ya build it whether it interferes with ingress or not.

    Michael[​IMG]
    <a target="_blank" href=http://www.jmartin.net/parker/goose.htm>www.jmartin.net/parker/goose.htm</a>
     
  4. Grim-Reaper

    Grim-Reaper 3/4 ton status Author

    Joined:
    Feb 17, 2000
    Posts:
    7,385
    Likes Received:
    0
    Location:
    Atlanta
    2 inch. I don't have door bars because I got kids gettting in and out. I also didn't do the B pillar shoulder bar for the same reason. Mine is VERY tight to the outside and getting in and out is really no worse than without a full cage. Getting in the back seat may be easier because you can grab the cage to steady yourself and pull yourself in.

    Women dig dents and flat paint!
    coloradok5.com/gallery/Grim
    75 Jimmy, Dollar
    Grim-Reaper
     
  5. Cavalry

    Cavalry 1/2 ton status

    Joined:
    Oct 1, 2000
    Posts:
    978
    Likes Received:
    0
    Location:
    upstate NY(although I cant figure out why)
    I build all mine out of 2"x .120 DOM Just remember you are driving a truck that if you roll it will most likely be at slow speeds. Not at 120mph in a car. I usally only build 6 pt cages for trucks. Make sure you are mounting it to something secure on the floor (not just the floorboards) frame mounting has its advantages and disadvantages. I did a cage for a jimmy a few years ago that I ran the "A pilar" bars down through the speaker holes in the dash pad. made for very little obstrucion..nothing to trip over when getting out

    "There is a fine line between hobby and mental illness"
    Luke
    84 K5
     
  6. Mudfreak

    Mudfreak 1/2 ton status

    Joined:
    Dec 16, 2000
    Posts:
    116
    Likes Received:
    0
    Location:
    NY
    Thanks guys, I've got the whole floor out of the blazer, front and rear, so I'm planning on attatching it to the frame. I never really thought about a cage, but reflecting on the number of times I have been on two wheels with the thing, I have re thought the idea.

    Door bars?, I'm not to familiar with what exactly these are? Do they go across the door? I will put the info to good use. Thanks again guys.

    88 K5... work in progress
     
  7. Mudfreak

    Mudfreak 1/2 ton status

    Joined:
    Dec 16, 2000
    Posts:
    116
    Likes Received:
    0
    Location:
    NY
    Calvary, I like the idea of running through the speaker holes, also, what are the adv/disadv of mounting the rollcage to the frame? I thought that would be the only way to be safe and secure in a roll over situation?

    88 K5... work in progress
     
  8. BogginChevy

    BogginChevy Registered Member

    Joined:
    May 18, 2001
    Posts:
    14
    Likes Received:
    0
    Where do you find tubing suited to constructing a roll cage and how do you bend it ect ect.

    Thanks,
    Ryan
     
  9. hammer

    hammer 1/2 ton status

    Joined:
    Aug 29, 2001
    Posts:
    449
    Likes Received:
    0
    Location:
    Binghamton N.Y.
    local steel and aluminum dealer will have it I suggest DOM tubing (drawn over manderal) It's like $25-30 for 20 feet. As forbending it I have a tubebender at work that I can do it find somebody local might do it cheap a couple bends or a freind for some beer sometimes works

    <font color=red>Let me at it I can break it</font color=red>
     
  10. BogginChevy

    BogginChevy Registered Member

    Joined:
    May 18, 2001
    Posts:
    14
    Likes Received:
    0
    The tube bender you refer to the big hydraulic benders you see at muffler shops right? I have a conduit bender, woudl that work haha j/k :)
     
  11. DesertDueler

    DesertDueler 1/2 ton status

    Joined:
    May 23, 2001
    Posts:
    3,106
    Likes Received:
    0
    Location:
    Phoenix, AZ
    No a muffler shop bender will kink the pipe you need an actual tube bender. Expect to pay about 500 for one. I ended up paying 750 for mine because I bought both the 1 and 5/8 and the 1 and 3/4 dies.

    86Jimmy 4"&35"MTRs,87 burb 4"&33"MT,69Firebird w/525 hp,and 70GTO live in PHX,AZ<a target="_blank" href=http://www.geocities.com/modifierperformance>My vehicles</a>
     
  12. Mudfreak

    Mudfreak 1/2 ton status

    Joined:
    Dec 16, 2000
    Posts:
    116
    Likes Received:
    0
    Location:
    NY
    I work at a machine shop , so I can get the materials ordered in. Getting the materials and machining them and welding them in isn't a problem. We actually have an ironworker that does punches and bending and cutting so I'm going to try the bending on that. If anybody has some pics, pleas post em or get me to a link to see them. Thanks1

    88 K5... work in progress
     
  13. Cavalry

    Cavalry 1/2 ton status

    Joined:
    Oct 1, 2000
    Posts:
    978
    Likes Received:
    0
    Location:
    upstate NY(although I cant figure out why)
    Mud-
    If you mound directly to the frame it will stiffen up everything in your truck considerably. Your body is isolated by rubber(or poly) If you mount the cage flat to the floor and then gusset down to the frame you have pretty much eliminated your body mounts. Some people use strips of urethane between the floor/gusses/cage but I dont think it flexes enough. I bolt mine to the floor(if the floor is any good plate the hell out of it if it aint) and then put gussets undernieth to the frame with urethane between but no mechanical connection(bolts) that way I still get flex and if the floor fails it has a permanent stop. Its kinda hard to explain so I hope my description is accurate.....oh bending tubing in a ironworker.....umm yikes! give it a try by all means but I would not expect much. To bend tubing the right way one must have both sides of the mandrel take a look at a few tubing benders and you'll see what I mean. Let me know if i confused you any

    "There is a fine line between hobby and mental illness"
    Luke
    84 K5
     
  14. michaelm

    michaelm 1/2 ton status

    Joined:
    Feb 2, 2001
    Posts:
    872
    Likes Received:
    0
    most of the time mounting to the frame will just lead to stress cracking the floorpan. unless you hard mount the tub to the frame.
    if you are after rollover protection and not frame strengthening mount the seats and belts to the cage in the tub
     
  15. Mudfreak

    Mudfreak 1/2 ton status

    Joined:
    Dec 16, 2000
    Posts:
    116
    Likes Received:
    0
    Location:
    NY
    Cavalry,
    Thanks man , I didn't think of the effects of mounting it to the frame. But now I got some really great ideas, thanks to you. Oh and yeah I see what you mean about the iron worker trying to bend that stuff. LOL ! on to plan B. I came down with this nasty cold, so I won't be able to get to work on it till I feal better, It's really kickin my ass! thanks again for the info.

    88 K5... work in progress
     
  16. Michael

    Michael 1/2 ton status

    Joined:
    Feb 17, 2000
    Posts:
    1,576
    Likes Received:
    0
    Location:
    Sherman, Texas
    Here is an article from another site that was posted the other day...pretty informative. You might also try a search on this subject....we've talked about it a lot. <a target="_blank" href=http://pirate4x4.com/tech/bendin_tube/index.html>Tube Bending 101</a> I still say HREW (Hot rolled electric welded) tube is fine for most non-racing applications....much cheaper than DOM......but do some research and decide for yourself.

    Michael[​IMG]
    <a target="_blank" href=http://www.jmartin.net/parker/goose.htm>www.jmartin.net/parker/goose.htm</a>
     
  17. AngusF

    AngusF Registered Member

    Joined:
    Nov 18, 2001
    Posts:
    7
    Likes Received:
    0
    Location:
    Edmonton, Alberta, Canada
    Man, that is the best site I have ever seen. Thank you so much for posting that. The one thing I haven't seen mentioned here that I think is very important is wall thickness. Almost all sanctioning bodies require .095" wall minimum, and for some sports, .120" is the minimum. If you're in CANADA, you can get 1 3/4" tube suitable for cages from UAP/NAPA, part number UNX 508134. I'm not sure on the exact wall thickness, but I've delivered many a length of that to one of our customers who builds stock cars, which require .095" thickness up here.
     
  18. Grim-Reaper

    Grim-Reaper 3/4 ton status Author

    Joined:
    Feb 17, 2000
    Posts:
    7,385
    Likes Received:
    0
    Location:
    Atlanta
    Well these are HEAVY vehicles. in all reality the roll that your most likly going to have is a slow lay over. You can go nuts an build a race car style cage but they are hard to live with as a daily driver. Typicaly most of us build a 6 or 8 point family cage and use .120. Thatr way it acn carry more weight over longer spans so you require les cros bracing. DOM is a bit of over kill for what we do. The Fact is DOM is still a welded seam. It had just had the seam smoothed out durring the manufacture process. Were not going to be having a wreck at 150mph. Tube splitting is not really an issue because our rolls do not deform the cage a great deal if at all.
    Mounting is the big problem. You need to make the mounting points as close to the load bearing braces and cab supports as possible. These vehicles lend themselves very well to the because of the location of the body mounts are right where you want to put the legs. Do not go to the top of the fenders. Run the rear legs all the way to the back corners where you can get close to the tailpan where there is the most strength.
    For the best safety mounting the seat to the cage is a good idea. If for some reason you do have a very violent roll and the bodyt or the cage seperate your still sitting in the cage. You will need to relocate your seat belts to the cage if this is your goal but remember the odds of this type of roll are about like hitting the lottery...pretty slim if you build it right and take care of any rust problems the body has.
    If you do decide to go for a frame mount I would put a captive bushing arangment simular to s spring eye to allow for some movement or make sure you make the frame rigid enough with the cage so as not to get into stress fractures on the floor where the mounts pass through. Becareful you don't over build it. THere is a point where your making it safe and there is a point were you just adding weight and raising the CG. I do feel that a bar in the center or diagonal in the top is a good idea. in a family style cage there is going to be a 4ft by 4ft opening that if you do go over would allow a large object like a rock or tree stump to have entery into the cabin area.


    Women dig dents and flat paint!
    coloradok5.com/gallery/Grim
    75 Jimmy, Dollar
    Grim-Reaper
     
  19. Mudfreak

    Mudfreak 1/2 ton status

    Joined:
    Dec 16, 2000
    Posts:
    116
    Likes Received:
    0
    Location:
    NY
    Great input, thanks guys, also great site!
    be puttin all the info to use here shortly!


    88 K5... work in progress
     

Share This Page