Spare tire carrier design - tube (feedback requested)

[T Y L E R]

Not sure if this is pure tech or not. More of a design issue really .. I'll leave it to the Mods.


I am interested in designing a really different spare tire mount for my 80. Here are some of my early ideas:

1 ) Made from tubing similar to that used in commercial sliders.
2 ) Will mount where my trailer hitch does now. I will remove the hitch.
3 ) One main tube bent symmetrically that rises up from the existing hitch mount points, curves tightly around the bumper and up against the tailgate before curving again along the same slant as the rear window, before mirroring itself back down under the bumper.
4 ) It would taper towards the top of the hatch where the tire would be mounted.
5 ) Cross members would be built in for stability/integrity.
6 ) My plate would remain unobstructed.
7 ) Where the carrier upright tubes curve up by the tailgate I've thought perhaps a few jerry can holders could be integrated adjacent to the license plate.
8 ) Some genius needs to figure out a way to allow the uprights to swing out of the way so the hatch can open. I don't care about opening the tailgate per se.


I can't help wondering if this were possible for a decent price that there might be a market for it. Since few angles are involved, and it's primarily tubing I was hoping costs would be kept down Might appeal to 80's guys wanting to keep their stock bumper but want a robust exterior spare mounting system, along with bonus storage for gas etc.

There has to be a beefy, tasteful way to do this. I guess I'm looking for that solid baja sort of style .. something like the mounts seen in truck beds.


Feedback?


TY

 

[topend yobbo]

Sounds very heavy with the jerrys included . Swing away spares are always a good idea though. If its not swing away ignore all above.

 

[Aussie cruiser]

With the spare up so high you will have no vision out the rear window.

 

[davegonz]

TY,

Try sketching something out.....You probably have some back of the napkin sketches of your ideas. Would help with the feedback.

 

[T Y L E R]

I was hoping to find a similar design online to post a pic, but looks like I'll have to try and draw something out ..

I thought about the view being obstructed while I drove back from Co. It's a sacrifice, but honestly I have been driving defensively at speeds for years without anything but my door mirrors .. at work. (medic)


I could quickly acclimate to it in a short time.


TY

 

[Aussie cruiser]

What about flex With the weight so high there would be a lot of flex in the frame work. having only one mount point (the reciever) it would allow a lot of movement. I have been rearended in a 60 and 80 both had bumper mounted tyer carriers and they both caused panel damage.The flex allowing the upright to hit the upper tailgate. With your proposed setup there would be even more movement unless you could some how brace it up high where the weight is

 

[T Y L E R]

It would be mounted in 'place' of the hitch. The hitch has bilateral mounting points nicely spread at the frame rails.

Maybe the addition on the jerry can carrier decks will allow some beefing up of the carrier. Cross tubes creating these decks and also boosting integrity.


I wonder if a guy like LandCruiserPhil could help .. hes around race trucks with tons of tubing This is one of his I think.

TY

 

[T Y L E R]

Something tells me Hanna would have little problem with this concept .. at least from a form perspective. Not certain on integrity yet...heck I could almost begin with what he has done here, by replacing the bumper and starting out really wide with side armor built in, and then work my way up .. sort of stretching upwards what he lays down in the bed in this 80.

 

[MoJ]

TY -
Might not make any difference to you but having the tubes running from the hitch mount points and then curving around the bumper is gonna equal a decreased departure angle.

On the other hand, I suppose they could act as a skid plate.

 

[T Y L E R]

TY -
Might not make any difference to you but having the tubes running from the hitch mount points and then curving around the bumper is gonna equal a decreased departure angle.

On the other hand, I suppose they could act as a skid plate.

I considered the skidplate angle .. I think I'm at the point in my build where that might not matter. I'd probably start tubing this thing if I wanted to start doing certain hard trails. For now it's mostly a trail rig in the sense of back country exploring .. no rocks for a while yet.


TY

 

[apcoleman]

One thing you could do if your vision is shot, is mount a rear camera somewhere kind of like an RV or backup cam that is always on. Just and idea...

 

[T Y L E R]

One thing you could do if your vision is shot, is mount a rear camera somewhere kind of like an RV or backup cam that is always on. Just and idea...

Cool idea considering I have the laptop right there! Hmmm .. thanx.





TY

 

[Cruisin'Carolina]

I think the higher up the tire is mounted, as previously posted, will present a problem for a heavy tire mounted too high. Probably not much predictability without experimentation.

I don't think the issue would be quite so serious if the mounting point wasn't under the truck, and came out and around the bumper.

Cool idea, maybe the strength of tubing could overcome that. But a 36 mounted up high will be heavy, and I would expect some flex. Maybe not enough to rebound back into the truck, but something to consider.

Sounds like it would be worth a few hundred in materials to try, git'r'done!!!

 

[Riad]

So what you are saying is you will just mount the bumber using the 4 threaded holes you have in the rear for the hitch. If so, then it is basically a straight upright, right? To get it out of the way you could do the hitch pin mechanism (or something similar) they have for bike carrier . It doesn't really swing out rather it swings down. So you would put in the pin to hold the upright straight up, take the pin off to pull the upright down to open your hatch.
How's that?

 

[T Y L E R]

So what you are saying is you will just mount the bumber using the 4 threaded holes you have in the rear for the hitch. If so, then it is basically a straight upright, right? To get it out of the way you could do the hitch pin mechanism (or something similar) they have for bike carrier . It doesn't really swing out rather it swings down. So you would put in the pin to hold the upright straight up, take the pin off to pull the upright down to open your hatch.
How's that?

Nope .. the trailer hitch mounts underneath the truck, next to the frame. I would use those 6 or 8 holes. Mind you when it sweeps up past the OEM bumper I could always add a cross pc that bolts into the threaded holes you mention, providing more stability.


The way it all hinges is what will seperate the posers from the pros in this project.



TY

 

[Nay]

Here is NW-Sickboy's setup. Just copy it

Focus in on a few things here:

This is how you get excellent strength without the weight (or cost).

Clearance, clearance, clearance. The main principle is that this bumper is tucked in closer than the stock crossmember, so he trimmed the frame and I assume relocated the crossmember. This is a) not minor and b) permanant.

The side tubing is tied back into the frame for support. Notice you don't see that low hanging exhaust - it is relocated (this is a major need).

All of these factors are extremely relevant. A lot of weight hanging off the back acts like a leverage arm. You want as little weight as possible, and what you do have should be as tight to the body as possible. If you don't believe that this makes a difference, try this:

Drop the tailgate. Sit on the very edge. See how much the suspension compresses. Now go and sit right over the axle in the 3rd row of seats. See how the suspension doesn't compress noticeably. It is not just about weight, it is how you distribute (and avoid) it.

The rear of the 80 is already too long - that the frame extends 4" beyond the body to form part of the bumper is troublesome in two ways: 1) even a small rear end collision can cause frame damage, 2) this is not helping depature angle, which is a problem on 80's.

When considering a front bumper, I think in these exact same terms (do I have to say again that you can design excellent solutions once you stop thinking that everything has to "bolt on"?)

A good fab shop should be able to do this for $600-$700 or so, but don't quote me. Having the use of a good fab shop? Priceless.

Nay

 

[Riad]

Aha. Gotcha. Good idea! I removed that hitch piece and tossed it. It's a clearance issue for me. Beside, that piece was pretty rusty. But you should be fine, now that you have the HYBRID suspension . As soon as I get my welding machine, I'm starting on some thing like this. This is my initial design (idea). Design 'A' is going to be a pain, 'B' seems much easier. 'A' is swing out, 'B' is swing down.

 

[Slomo]

I thought about the view being obstructed while I drove back from Co. It's a sacrifice, but honestly I have been driving defensively at speeds for years without anything but my door mirrors .. at work. (medic)


I could quickly acclimate to it in a short time.


TY

TYLER,

For what it is worth we have tried similar ideas for desert racing chase trucks that are largely stock and don't want to replace bumpers and only need the spare carrier for the races. Even with stout mounting where the reciever was the distance of the tire from that point creates movement that is hard to overcome without another attachment point near the top. We have the dented tailgates to prove it.

Off topic but just wanted to say yo to a fellow medic. After driving a rig without a useable center rearview mirror for years I agree it is highly over rated. If you do ever make it down to Cali you are on for beer, sushi and girls!



Mark

 

[Arya Ebrahimi]

Call me lazy, but tire carriers in general pretty much kill the use of the rear tailgate IMO. Sure you can use the rear tailgate, but it becomes quite hassle. On my old truck I pretty much stopped using the tailgate once I put a tire carrier on it.

Now if you told me that everytime I wanted to get into the back of the truck I'd have to lower a 36" tire on a swing-down mechanism, and then lift it back up to close everything up, I don't think I'd ever use the rear gate.

This may or may not be a problem for you.

Ary

 

[T Y L E R]

Nay, I like NW-Sickboys bumper there .. really good start if I go that route.

Riad, I would want to reinforce that design with the actual hitch mountng points, and use really beefy tubing if it's going to be a single upright.

Slomo, thanks for the invite dude! BTW we have a few other medics on this board. As for the bumper, I wonder if I could use a stiffer alloy for parts of this design to give it strength and rigidity?

Ary, I don't like the idea of lowering such a big tire, but I could get used to a swingout like NWSB's above. But being a symmetry freak, it would have to be similar to his where the swing out arm is full width, with the carrier up the centre.



TY