Telescoping RTT Rack Design Question

[KellyM]

I currently have a fixed rack on my trailer that is too high for my taste, and I want to go to a telescoping rack to have a low position for transit and the ability to raise it at the campsite to take advantage of the RTT annex. Most of the telescoping racks I seen have the larger tubing on the bottom with the smaller tube attached to the rack and sliding into the larger base tubing. Is there a strength or other reason for this? My thought was that if the smaller tubing was on the bottom and the larger tubing slid over that, there would be considerably less debris (dust, mud, sand, etc.) that could get into the larger tube. I'm sure I am missing something here, and any help would be appreciated.

 

[Hoghead]

I did mine with the larger on the bottom, but if I build another, I am thinking of going the route that you are describing. I don't think the strength will be an issue.

 

[achuto]

Putting the smaller size tube on the bottom limits your choices of securing it to the trailer. You only point of contact would be at the bottom giving no lateral support whereas the large diameter can be fastened toward the top adding strength. I added a rubber grommet on the top of the larger tube that helps keep the dust out.

 

[Martyinco]

Putting the smaller size tube on the bottom limits your choices of securing it to the trailer. You only point of contact would be at the bottom giving no lateral support whereas the large diameter can be fastened toward the top adding strength. I added a rubber grommet on the top of the larger tube that helps keep the dust out.

Bingo, that was my reason for the larger tube on the bottom as well. There was not safe way for me to attach the smaller size safely.

 

[Kiddmen57]

what trailer? Have pics of the current setup? from there the discussion can have an idea of what you're working with and provide more directed opinions.

 

[KellyM]

Putting the smaller size tube on the bottom limits your choices of securing it to the trailer. You only point of contact would be at the bottom giving no lateral support whereas the large diameter can be fastened toward the top adding strength. I added a rubber grommet on the top of the larger tube that helps keep the dust out.

Hey now - I did not think of the securing issue, but it makes complete sense! Thanks. Would you mind posting a picture of your trailer rack? BTW, I love the mid 60s CJs.

 

[KellyM]

what trailer? Have pics of the current setup? from there the discussion can have an idea of what you're working with and provide more directed opinions.

Here are a couple of pics of the current setup.





My next dilemma is that the existing rack is made with rectangular tubing, and I have not been able to find telescoping rectangular tubing. My initial thought was to cut the uprights at the tub top rail and weld on new smaller rectangular tubing to the rack itself. But now I am thinking I may need to go with all new upright pieces and buy square telescoping steel. What do you think?

 

[Ovrlnd Rd]

Actually you could have the smaller tube on the bottom, weld a brace part way up (say 3/8" offset from the trailer tub), then have the larger tube slotted to go over the offset. The minimal structural loss from the slot really shouldn't be an issue with the weight spread out over 4 uprights.

 

[achuto]

what trailer? Have pics of the current setup? from there the discussion can have an idea of what you're working with and provide more directed opinions.

Here's the trailer in the travel/one night stopover mode. Outer tubes (1 1/2" dom) secured at the bottom and along the top rail of trailer. Inside are struts to help lift the RTT. Top tube is 1 1/4" dom.

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Here is the "we are staying more than 1 night mode". Unscrew tie down bolts, lift RTT and reset bolts.

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[JKChad]

Here's a few of the rack I just had built. The builder used 2"x2" .120 for lower, larger, tube, and 1.5"x1.5" for the upper post and rack it self. I'll have .060 UHMW strips attached to the 1.5" tube to help reduce friction and also help with the .250" difference. I want a little bit of play to allow the lift struts to be able to slightly​ lift one side as I release the rack from the low position. Once I pull the the lock pins on the opposite side, all 4 struts will lift the tent up to the high position and the lock pins will automatically lock back in.

I am working on the strut install tomorrow. I'm planning to have the lift struts mounted inside the tubing for protection and because I like to over complicate things. Lol.. Hoping I can get it functional tomorrow. If so, I'll post some videos.

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[Jdavera]

Also you can use shocks boots to protect the telescoping tubes

http://www.4wheelparts.com/Suspensi...tid=SKYB10OG&gclid=CPOlsPiJ0NICFQcwaQodsZ4MmA

 

[KellyM]

Here's a few of the rack I just had built. The builder used 2"x2" .120 for lower, larger, tube, and 1.5"x1.5" for the upper post and rack it self. I'll have .060 UHMW strips attached to the 1.5" tube to help reduce friction and also help with the .250" difference. I want a little bit of play to allow the lift struts to be able to slightly​ lift one side as I release the rack from the low position. Once I pull the the lock pins on the opposite side, all 4 struts will lift the tent up to the high position and the lock pins will automatically lock back in.

I am working on the strut install tomorrow. I'm planning to have the lift struts mounted inside the tubing for protection and because I like to over complicate things. Lol.. Hoping I can get it functional tomorrow. If so, I'll post some videos.

Sent from my XT1650 using Tapatalk

That looks great! Thanks for posting. I couldn't quite see in the pictures what is on the backside of the lock pins. Are those the mounts for the gas struts? Do the lock pins go all the way through both the inner and outer tube?

 

[KellyM]

Also you can use shocks boots to protect the telescoping tubes

That might be a nice way to keep some of the crud out of the tubes. Thanks.

 

[Mushin_Noshin]

https://youtu.be/fISE7lSaAQ4
This is how I did mine, larger tube on bottom, zero issues with dirt or crud

www.overlandgearexchange.com

 

[JKChad]

That looks great! Thanks for posting. I couldn't quite see in the pictures what is on the backside of the lock pins. Are those the mounts for the gas struts? Do the lock pins go all the way through both the inner and outer tube?

Those are bolts that act as a secondary lock/pinch bolt. The pop pins, black T handles, are heavy duty but only pass through one side of the tube. The bolt on the outside edge was added by the builder as a way to ensure the rod from the pop pin can't slip out. It also help take any slack out to keep the rack from rattling going down the road. I will be replacing the bolt with a 3 or 4 prong knob I can easily turn by hand.
The struts will actually be hidden inside the tubing. I'm using 60lb 20" stroke struts from liftsupportdepot.com.

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