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  • Bar out over the side/rear from the roof

    Has anyone ever seen or have any thoughts on installing a steel bar on the roof that i could hang gymnastic rings from?

    My thought was to install 2-3 steel brackets on roof to studs and allow bar to be slid out off the rear of the trailer and secured then slid back so it doesn't hang out while driving. would need to stick out about 3 feet and support around 200lbs

  • #2
    Originally posted by lager911 View Post
    Has anyone ever seen or have any thoughts on installing a steel bar on the roof that i could hang gymnastic rings from?

    My thought was to install 2-3 steel brackets on roof to studs and allow bar to be slid out off the rear of the trailer and secured then slid back so it doesn't hang out while driving. would need to stick out about 3 feet and support around 200lbs
    Hmmm.
    This is a tuff one. I would think that 3' of stick out to support 200# would require about 6' attached to the roof. The other item of note would be I would not trust screws down into the roof trusses to support that weight. I would tend to think that a bolt thru the roof and a steel plate on the ceiling inside would be in order to achieve this. The 200# weight is important but also you need to add the swinging and bouncing on the rings so this actual weight may approach 400# or more. I am sure that the engineers will be along with some type of theorem to calculate what you may need. A nice large tree may be the ultimate answer.

    Welcome to the Forum , this by far is the strangest request I have seen but also very interesting and cool that you use rings so much that you will use them when camping.

    Brian
    Brian & Michelle
    2018 Reflection 29RS
    2022 Chevy 3500HD

    Comment


    • #3
      Originally posted by Country Campers View Post

      Welcome to the Forum , this by far is the strangest request I have seen but also very interesting and cool that you use rings so much that you will use them when camping.
      Thanks, got the 21BHE last November and got out for the first time last weekend. I actually replaced my entire gym work out with rings and dumbells. I have done the tree and playground but want an easy to setup solution that I know I'll always have. Also not a big fan of using the rings out in front of everyone.

      Originally posted by Country Campers View Post
      I would think that 3' of stick out to support 200# would require about 6' attached to the roof. The other item of note would be I would not trust screws down into the roof trusses to support that weight. I would tend to think that a bolt thru the roof and a steel plate on the ceiling inside would be in order to achieve this. The 200# weight is important but also you need to add the swinging and bouncing on the rings so this actual weight may approach 400# or more.
      I agree there about the extra distance on roof. Even if we assume 400 lbs that's only 200 lbs at 6 ft onto roof and split between 4 screws would be 50lbs a screw. i guess that's a bit high for them. Really interested in what others have to say. * running off to tell the wife i'm putting a steel plate on her ceiling*

      Comment


      • #4
        About 2.5 ft hanging over side, accounting for bouncing, will be around 300lbs applied between the hooks at about 1.75ft from side. Total length is 8 ft. I'd love some feedback and help with how to anchor this to the roof including adding wood/metal plates to spread out force when in contact with roof as well as ways to anchor to studs.

        Comment


        • #5
          Originally posted by lager911 View Post
          About 2.5 ft hanging over side, accounting for bouncing, will be around 300lbs applied between the hooks at about 1.75ft from side. Total length is 8 ft. I'd love some feedback and help with how to anchor this to the roof including adding wood/metal plates to spread out force when in contact with roof as well as ways to anchor to studs.
          I'm no engineer, but given what I know about RV construction...I don't think this is a good idea. That's not what you want to read--I understand--but if the roof rafters come ripping out (along with the TPS roofing)...that's going to generate a very expensive repair.

          My opinion is not worth a cup of coffee, and I mean no offense, but put me in the "don't do this" camp.

          Howard
          Forum moderators are not GD employees--we are volunteers and owners presumably just like yourself. Unless specifically mentioned otherwise, we have nothing to gain should you choose to purchase a product or engage a service we discuss on this forum.

          2017 Ford F-350 DRW, '19 315RLTSPlus

          Comment


          • #6
            There are many factors that must be considered for this Issue and it may be very problematic.

            1. Most of the force will be concentrated at the edge of the roof/wall interface. This will apply a crushing force to the interface which could very easily damage or destroy the roof edge or top of the wall. This crushing force can cause the fiberglass to spread and delaminate. The only way to minimize this would be with a large plate that would help spread the load.
            2. The bar nearest the fulcrum point (edge of the roof) will see a compressive load. As you transition from the edge of the roof, the bar and screws will be under tension. This means that the bar will be pushing down on the edge, and lifting on the end that is over the roof.
            3. The load will not be static, but dynamic. This changes the basic moment arm calculations. As you can probably picture, the load will be shifting dramatically as the gymnast imparts movement to the system.

            In order to provide accurate calculations, we'd need to know the strength of material numbers for the roof assembly, roof edge, and wall assembly. In addition, in the photo, you placed the bar directly over a window which complicates the calculations. Personally, I would not risk damaging the wall or roof with this project. It would not be covered under the three year structural warranty if there was a failure.

            How about another option? Is there a portable gymnast bar solution available?

            Jim
            Jim and Ginnie
            2024 Solitude 310GK
            GDRV Technical Forum Moderator
            GDRV Rally Support Coordinator

            Comment


            • #7
              Originally posted by howson View Post

              That's not what you want to read--I understand
              Wouldn't have posted if I didn't want your opinion !! Thank you for the reply

              Comment


              • #8
                Originally posted by TucsonJim View Post
                There are many factors that must be considered for this Issue and it may be very problematic.

                1. Most of the force will be concentrated at the edge of the roof/wall interface. This will apply a crushing force to the interface which could very easily damage or destroy the roof edge or top of the wall. This crushing force can cause the fiberglass to spread and delaminate. The only way to minimize this would be with a large plate that would help spread the load.
                2. The bar nearest the fulcrum point (edge of the roof) will see a compressive load. As you transition from the edge of the roof, the bar and screws will be under tension. This means that the bar will be pushing down on the edge, and lifting on the end that is over the roof.
                3. The load will not be static, but dynamic. This changes the basic moment arm calculations. As you can probably picture, the load will be shifting dramatically as the gymnast imparts movement to the system.

                In order to provide accurate calculations, we'd need to know the strength of material numbers for the roof assembly, roof edge, and wall assembly. In addition, in the photo, you placed the bar directly over a window which complicates the calculations. Personally, I would not risk damaging the wall or roof with this project. It would not be covered under the three year structural warranty if there was a failure.

                How about another option? Is there a portable gymnast bar solution available?

                Jim
                Took it off the roof and hooked it up on a deck railing. While it worked well off the deck raining it did cause huge compressive forces. The tension i don't think would be a problem due to the different moments but the compression at the corner i think is where it would fail over time and you last statement is what ultimately will talk me out of this "it would void any kind of warranty i have!!"

                Comment


                • #9
                  Originally posted by lager911 View Post

                  Took it off the roof and hooked it up on a deck railing. While it worked well off the deck raining it did cause huge compressive forces. The tension i don't think would be a problem due to the different moments but the compression at the corner i think is where it would fail over time and you last statement is what ultimately will talk me out of this "it would void any kind of warranty i have!!"
                  But! I've been thinking about this. What if you supported the free end with a couple of bars that run to the ground? Kind of like a fifth wheel king pin support And then support the roof side with a large plate of wood or steel. I'm just thinking out loud...

                  Jim
                  Jim and Ginnie
                  2024 Solitude 310GK
                  GDRV Technical Forum Moderator
                  GDRV Rally Support Coordinator

                  Comment


                  • #10
                    The loads on the roof trusses will be the reverse of what they are designed for. The trusses are curved on the top and flat on the bottom to resist downward compressive forces such as snow load. The upper arch in compression and the lower member in tension. To reverse that load direction and put the lower straight member in compression and the reverse curve upper member in tension will have unknown results.

                    Rob
                    Cate & Rob
                    (with Border Collies Molly & Angel + Kitties Hazel & Elsie)
                    2015 Reflection 303RLS
                    2022 F350 Diesel CC SB SRW Lariat
                    Bayham, Ontario, Canada

                    Comment


                    • #11
                      lager911 Cate&Rob TucsonJim howson
                      The engineer in me got to thinking here. Have you considered a free standing gym?
                      https://nimblesports.com/product/adj...yABEgJIcfD_BwE
                      https://www.amazon.com/dp/B07H25C9XR...opdailyboth-20

                      Otherwise possibly consider a system where one support clamps to one side of the ladder (full length support) and has a top bar attached to that upright that extend3 to 4' to a second support that has base legs for stability.
                      Hope this helps
                      On edit https://khanhtrinhvn.com/all-products/
                      2018 Reflection 150 Series 220RK 5th whee, Star White 2022 F350 King Ranch CC Long bed (HAL) (CCC 4062lbs), B&W 25K OEM Companion,. SteadyFast system, Trailer reverse lights, rear receiver spare tire holder, storage tube, sumo springs, Victron MultiPlus 12/120/3000, Solar, Custom 6K axles upgrade, and other modifications.

                      Comment


                      • #12
                        Not to disrespect anyone but this is a bad idea where otherwise this is a simple cantilever beam problem.

                        Jim
                        Last edited by Guest; 06-01-2020, 12:56 PM.

                        Comment


                        • #13
                          Originally posted by TucsonJim View Post

                          But! I've been thinking about this. What if you supported the free end with a couple of bars that run to the ground? Kind of like a fifth wheel king pin support And then support the roof side with a large plate of wood or steel. I'm just thinking out loud...

                          Jim
                          Thought about this or even an angled piece that went to the bumper but that is beginning to be too much extra equipment

                          Comment


                          • #14
                            Originally posted by Yoda View Post
                            lager911 Cate&Rob TucsonJim howson
                            The engineer in me got to thinking here. Have you considered a free standing gym?
                            https://nimblesports.com/product/adj...yABEgJIcfD_BwE
                            https://www.amazon.com/dp/B07H25C9XR...opdailyboth-20

                            Otherwise possibly consider a system where one support clamps to one side of the ladder (full length support) and has a top bar attached to that upright that extend3 to 4' to a second support that has base legs for stability.
                            Hope this helps
                            On edit https://khanhtrinhvn.com/all-products/
                            My problem with these is the setup part and storage in a small 21bhe. Otherwise though I like a lot of these!!

                            Comment


                            • #15
                              Originally posted by Cate&Rob View Post
                              The loads on the roof trusses will be the reverse of what they are designed for. The trusses are curved on the top and flat on the bottom to resist downward compressive forces such as snow load. The upper arch in compression and the lower member in tension. To reverse that load direction and put the lower straight member in compression and the reverse curve upper member in tension will have unknown results.

                              Rob
                              never even considered the pull vs push load difference on the trusses. looked at them through the roof vent an air conditioner spot an they seem pretty sturdy at least to support 100 lbs in either direction. the corner piece would be supporting 200-300 but would be the direction designed for.

                              Comment

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