Dumb question, spare tire and roof rack

[sirhk100]

I typically just have my spare tire strapped down in the rear. I'm heading out on a pretty decent road trip this weekend though and a bit of preplanning... I'm not sure how strapped I'm going to be for space inside with the tire in there too. I see it all the time on Cherokees but haven't spotted an expo doing it, I'm sure I'm going to have endless replies saying it's fine but wanted to check.

Am I safe tossing a 35" spare strapped up on my roof rack for a few days? We're going to be doing roughly 200 miles of dirt and probably about 500-600 miles of pavement.

Yes, I know my mileage will suck, yes I know the weight up top is optimum. I'm not doing any crazy crawling where things may get tipsy and I'm not out to win a race in the dirt or be the weekend drift king either. I'm not concerned about the top weight. Gas prices suck so that will add to the suck but it is what it is, do I want supplies and gear and spares or do I want a spare tire in my cab and leave that stuff at home, I'm siding with the spare on the roof.

So... other then the obvious drawbacks... Should I have any concerns tossing a 35" BFG Baja terrain on a 15" steel rim up top on the factory rack for a 3 day road trip?

Thanks,
Khris

 

[Mr. Truckles]

I keep a 33 and a hi lift up on mine 24-7. Highway mpg definitely sucks with it up there and the wind blows you around a bit more but it's manageable. I've only lost one so far in the woods due to a rotten strap and some serious shock blowing whoops but as long as it's secured well it should be fine.

 

[Anime]

Other than the obvious drawbacks, just throwing a 35" up on the factory rack might mess up the roof some, since the majority of the weight of the tire will be right in the middle where the sidewall of the tire contacts the (curved) roof, in the weakest part of it. This will be compounded when hitting large bumps, especially off road, and so you might wind up with two large dents up there. If you're lucky, the tire might only contact the rub strips, but even if it does, there's a chance it will eventually push them (and the roof) down so the sidewall contacts the sheet metal. You might also just get the same thing from strapping it down tight.

Usually when people throw a spare up there, it's on a heavy-duty roof rack that mounts to the rails, and puts the weight out to either side where the body can handle it.

I'm not saying it will happen, plenty of people have thrown 29-33 inch spares up there without issue, it's just more likely to happen with something as big and heavy as a 35". Putting a sheet of wood (something like a sheet of 1/4 in plywood that will conform to the curvature of the roof) under the tire might help keep the weight distributed on the rub strips.

If you have an actual roof rack with cross bars and mounts that put the weight into the roof rack rails, then it should be fine.

 

[sirhk100]

Nope, literally dealing with the factory roof rack... Guess I'll play with it tonight. Tossing a board to spread the load actually had crossed my mind with only concern of it turning into a wing and trying to actually take off at highways speeds. LOL not the exploder, but the board with the tire on it...

I may actually try to get fully loaded tonight so I have all tomorrow to figure out adjustments.

 

[Bruces expo]

The Stock Roof Rack on my 91 Navajo was barely strong enough for a stock sized spare , I took some random material I had laying around and fabbed up a small spare tire carrier on top , I have a full size 33-12.50-15 on a steel rim and My mpg didn't change one bit , if anything it helped with a little body roll I had before the spare was on top . I mounted the metal to the outside rails and then just strapped the tire to the actual material I used , Over 350+ Miles back and forth to work and it has held up fine for me .

 

[sirhk100]

Interesting, thanks for the heads up! May have to rethink this a bit then. May try to stand it up inside then to make for more floor space... Hmmm...

 

[Mr. Truckles]

Now that I look at it I agree. I'm used to the rack we had on our old '91 and I keep forgetting that it wasn't original.

 

[Anime]

If you're going with others, will anyone else have room to take the spare along, say in the bed of their pickup? If you're lodging somewhere or camping out, you can then keep whatever you're not taking with you on the trail there, and stick the spare in the back and then whatever supplies you take with you on the trail.

If you're going to be driving the trail with a vehicle stuffed full with supplies PLUS the weight of a spare tire, all that weight might be a problem, plus there's a safety issue with weight shifting and having all that gear in the back that could make it's way forward and interfere with your driving. Depending how the vehicle is packed, it could be very dangerous. The seat rails are pretty strong, but if you've got enough gear back there when you're going down a steep drop, it can all shift foward with enough force to push the seat forward, pushing you into the steering wheel and possibly causing quite the predicament, especially if one leg jams into the gas pedal and the other can't get to the brake.

 

[Maniak]

Back in 2007 I had it on the roof.. Literally, the roof. That is only a 33x12.50 though..

Here are a couple shots where you can see it tied down.. Eventually I got a basket from Costco (still use that) and even later I made my own cross bars..

IMG_5496 by maniak_az, on Flickr

DSC_0096_resize by maniak_az, on Flickr

I never had any issues with the tire up there.. Roof wise or the tire coming loose.

~Mark

 

[Travisfab]

Khris - Hit the junk yard and get a 3rd rack going!

 

[jd4242]

I put mine on the roof and never had a problem. I did get a third rail for some reason, cant remember now.just strapped it in a X using the side tie downs not the rails.it was only a 33x12.50, cant see a 35 weighing much more.

And I know all about LOADED down..only had room for me and my dog, had front and rear carriers full also..

 

[sirhk100]

Spare tire mount of some sort is definitely on my to do list. I managed to stand it up on the inside strapped vertically and had zero issues the whole weekend. 770+ miles with 200+ of it being in the dirt and I was solo vehicle wise. Just me and the passenger...

If you look close you can see it standing up on the passenger side here...

General pics from the trip...

 

[Travisfab]

Nice! Looks hot

 

[jd4242]

Hey I've seen those moving rocks before!!! Things will blow your mind!!!(9 picture for those that dont know, they move all by themselves)

 

[sirhk100]

Was mid 70's in the higher areas, highest we saw was 102. Wasn't bad considering home is Vegas for me. A/C worked great! Had a super fun trip! Can't wait to get back again probably next desert season. I think we squeaked this run in just before the real heat kicked in!

 

[Kiliona]

tbh I'd rather strap it to the rear tailgate than the roof. Or the hood if it weren't for visibility problems.

Like you said, bad mpg, weight up top is not optimal, get blown around on the freeway, blah blah if you can stand those things than go for it.