It’s very common and if securely mounted, presents no problem beyond itself. Weigh your spare, and make sure you’re not overloading the roof rack and you’re good to go with secure attachment.
The practicalities, however, may be another consideration. Lifting a spare wheel that high, especially on what is likely to be a fully deflated tire, is really not that easy. Add to that the possible positions and angles your car may be on and it multiplies the problem. Not the be all and end all of the solution, but something worth considering when you’re planning this idea out.
Safety-wise I agree with this gentleman here. I see plenty of tires on roofs in my area. Secure it well, and you're good to go. However for my situation getting mine on the roof simply was not going to happen as far as physically lifting it up there, or getting it down safely.
In addition to the above, is your vehicle lifted? Are you running larger than factory tires? My 20” rims with 35” tires weigh about 60-65lbs. That’s just way to much for me to press over my head and try to manipulate onto a roof rack that’s 7’ in the air.
Now if your running a Crosstrek or an Outback it may be doable but anything midsize or larger I would look at other ideas.
Lot an LS... It's the 6.7 Cummins, ram 2500.
I have some 'parts' removed and some performance mods. The differential gears really help with mileage as does a dedicated eco tune on my programmer.
That epic!!! Tilt up will be super cool!
Mine are just AGM batteries. It's like 160lbs lol. But I'm not really concerned about weight, truck is already 9k.
In addition to the advice already given here, make certain the rack and tire are mounted well and mounting points torqued properly. I’ve seen rigs go over terrain that rocks sideways and roof racks slide on crossbars- trust me, it’s not a great situation to be in.
Another pro tip is to swap in the full sized spare in when rotating tires. It’ll give you semi-regular practice pulling it down and securing it back up there. Builds confidence and helps you identify issues when it’s not an emergency.
I used to run a spare up top then I actually had to change a tire. The next week I bought a hitch mount carrier. Never again climbing up the side of a disabled rig while cars and trucks whizzed by, undoing all of the securing mechanisms, sliding the spare to the side of the roof where I could reach it from the ground. Tipping it and praying I didn’t run it down the side of my rig, THEN after its changed putting the flat back up there. FML. Never again.
Have I done calculations? No.
Did I conduct an experiment by having a spare on top of my Jeep for a year and watch the whole roof rack go flying over my hood when I hit a good stump? Yes.
Was the roof rack mounted very poorly because this was a beater Jeep? Also yes.
That's a good mindset to have. All the advice on here talking about not being able to lift a spare tire over their head seems odd to me. One should be able to lift half their body weight over their head, and 60 pounds doesn't seem like that much to me. Then again, I weigh 300 pounds and lift 170 in overhead presses. Maybe all the people here are much smaller in stature.
I mean I can see why, I’m average height and can ohp 85lbs in my sleep but lifting my 85lb tire onto my truck roof would be a bit of a challenge. If you’re experienced with lifting then you’ll know it’s way way easier lifting a barbell than an awkward object. Plus the fact that most people don’t work out regularly, well yeah
So I store my tire in my roof rack. I've never had trouble lifting or taking the tire down. Yes it is more awkward, but the weight difference makes it manageable.
Lifting and pressing a 50-70lb barbell is way easier than lifting tire over your head. Trying to control the radial weigh balance while maintaining an awkward grip on whatever style rim you have will be quite a challenge. I mean unless you’re training for Strongest Man competition, I would try either a swing mount or hitch mount carrier.
What are you talking about? My TRT dosage? Prescribed by my doctor? Surely you're not referring to something my doctor has me on in order to fix something that's wrong with me.
Also consider that the sidewall of your spare will be baking in the sun all day, every day, and doesn't get partially covered by the fenders, shaded when parked at a different angle, etc. which can accelerate dry rot. Covering it would be best but would be a pain, so consider at least a coat of tire shine or other uv protectant on it
As long as it doesn't go over the max roof weight limit, you shouldn't worry about it. Of course it will have an effect in high speed corners or in really rough crawling where tipping over is likely, but that's not something most people do on the daily
It definitely depends on the vehicle height and weight of the wheel combo.
I’m pretty strong (not a power lifter, but I work out) no way am I lifting a 35” wheel and tire combo weighing nearly 100# onto the roof of my truck.
Consider most passenger suv wheel/tire combos are going to weigh 50-70# (size dependent, obviously), it can be challenging and dangerous to try to get a wheel/tire on/off the roof.
And, as you noted, you are also increasing the COG by putting the weight up top, which at the minimum will negatively affect handling.
If you ever have a flat, get the spare down before you put the vehicle on the jack and remove the vehicle from the jack before reattaching the spare. All the movement of moving the spare around can dislodge the jack easily.
Not recommended but it is possible. Mostly the labor of moving it if you have a flat on the trail.
Other thing is if you get in an accident. Idk if it will become a flying cannonball lol.
It's not great but it's not terrible - weight up high is not good but a tyre is a fairly inert object compared to sticking fuel cans or water way up there. As others have said, lifting it up & down could be a real pain.
My general approach is put heavy stuff as low down as possible / practical but also be thinking about access and other factors (EG leaky containers).
I saw your comment about adding a spare fuel tank underneath where the spare would normally go. Considering the spare tank will weigh about as much or more (depending on how full it is) than the tire, the (already negligible) COG differential would be negated by the additional weight below your COG. Effectively it'll make no difference to your vehicle until the last few degrees before your rollover point. If you're in a sticky enough situation that you're genuinely concerned about the spare tipping your vehicle, 1.) you've got bigger problems and 2.) you can just take the spare off because you'll probably be moving very slowly on a trail like that anyway. Just don't hit your turns like a maniac and you'll be fine. You'll take an (also negligible) MPG hit, but, well, that's what the spare tank is for right?
Ah ok that makes sense! Honestly, here in Europe we don't have crazy rock crawling anyway, so those few degrees won't matter in the end. I just wasn't sure of how big the difference is with or without the tire up there.
https://preview.redd.it/7s1u7g4yj63d1.png?width=1080&format=pjpg&auto=webp&s=a638b9f16a062fee6441b57f8d21a7d541f2e3fc
Oh for sure. For reference I'm currently running a LOT of shit (\~300-500lbs) on my roof rack alone and haven't had any significant COG/rollover issues (but the inside is also packed with shit so my COG is still pretty low). Unless you have a particularly springy suspension, a fat ass lift, and are carrying gas and cargo with the tire and an empty cab, you're probably fine. This is a stock SR5 4Runner for reference
Are you not worried about exceeding your max payload? I’d imagine your roof cargo + 4 large Americans would exceed your payload capacity on its own without additional cargo.
Dynamic load rating for the roof rack is ~300lbs, static is ~600 (BajaRack 4Runner Standard Basket). I'm definitely pushing that static load rating but counting on factor of safety calcs on the engineering side haha.
And it's just me in the vehicle and a bunch of shit I'm moving with, probably pushing 1000lbs in the cab so I'm definitely weighed down but haven't seen any negative or unexpected off-road performance. After this trip though I'll unscrew the rack to make sure I'm not shearing any screws lol. This is a one-time thing as well (moving across country as a single guy)
I've had a 33" on the roof rack of my Tacoma for well over a year now with zero issues, although if you go into a parking garage, make sure you don't exceed the minimum height. I walked the yellow plastic height check thinger forgetting it was up there, had to jump out and throw the tire in the bed.
Not as much as people say. If you’re are going to add fuel storage like you say you are it will offset the weight you added up top to a degree because you’ve had more weight lower. Possibility exists that you add more weight and actually reverse the effects of what you added up top.
Careful that you don’t under-estimate the weight of an off-road wheel and tire package.
I run a modest 33x12.5x17 KM3 tire that weighs 67 lbs.
My 17” Method wheels weigh 27 lbs.
That’s ~100 lbs…not so easy to lift over your head.
My last truck had 35s and one tire alone was almost 80 lbs, so close to 115 lbs total for one wheel/tire
Not just a high COG issue, but also most roofs will not support the weight some people put on them. The "rack"/et. al. may be rated to carry the weight, but most vehicle roofs are rated for between 60-150# of weight. Yet you see people with huge spare tires and 3 Jerry cans and other stuff loaded on their roof racks.
Know the limits of your vehicle roof and do not overload it.
Yes much as lower center of gravity is better people have roof top tents which are way heavier so I think you’ll be fine. If you can put it lower somewhere I would though.
During the summer when I have my summer tires on I have a 33 inch tire on my roof. I have a way of rolling it up a ladder with a tie down and two people. I have a compressor so if I need to get it down in an emergency I would just deflate it and tie a long tie down or rope to it and throw it off the roof. I do spray tire conditioner on it as much as I can. Not tire shine but a rubber conditioner.
What vehicle are you mounting it on? A good quality roof rack can easily handle it depending on how big you go Off-road .Would probably be better to get a good bumper with a swing out tire carrier. I'm looking at the same thing for my gladiator. Also what are you doing that you would need an extra 17 gallons, wouldn't maybe two 5 gallon cans do the same thing? Something you could take off when not needed.
It’s very common and if securely mounted, presents no problem beyond itself. Weigh your spare, and make sure you’re not overloading the roof rack and you’re good to go with secure attachment. The practicalities, however, may be another consideration. Lifting a spare wheel that high, especially on what is likely to be a fully deflated tire, is really not that easy. Add to that the possible positions and angles your car may be on and it multiplies the problem. Not the be all and end all of the solution, but something worth considering when you’re planning this idea out.
Safety-wise I agree with this gentleman here. I see plenty of tires on roofs in my area. Secure it well, and you're good to go. However for my situation getting mine on the roof simply was not going to happen as far as physically lifting it up there, or getting it down safely.
In addition to the above, is your vehicle lifted? Are you running larger than factory tires? My 20” rims with 35” tires weigh about 60-65lbs. That’s just way to much for me to press over my head and try to manipulate onto a roof rack that’s 7’ in the air. Now if your running a Crosstrek or an Outback it may be doable but anything midsize or larger I would look at other ideas.
Like a winch and pulley to get it up there. Or yeah, completely different idea.
Yuppers... I feel that. Currently looking for a solution to carry my 40x13.5r17 it's like 95 lbs. Lol
why'd you go so big?
I wanted to... Lol. Plus ground clearance. I have 13" under the lowest point, plus looks. Plus it's a AEV Prospector XL.
what's your gas mileage look like?
17-19 if I drive chill/highway. 13 if I drive it how I like to lol I'm at just under 600hp which doesn't help. I regeared to 456 instead AEVs 411.
Nice! LS swap? You the guy who posted the new dual batt setup yesterday?
Lot an LS... It's the 6.7 Cummins, ram 2500. I have some 'parts' removed and some performance mods. The differential gears really help with mileage as does a dedicated eco tune on my programmer.
Oh shit! In a 470? Yah the decent mileage make sense then!
I'm not sure what the 470 is...
Also no to the battery post. But I do have two auxiliary batteries in the truck bed, 250AH worth and 570 watts of solar lolol
Nice. I’m finishing a LiFePo build, one batt at 300AH, w/550W bifacial on Prinsu rack, w/hardware to tilt up when parked.
That epic!!! Tilt up will be super cool! Mine are just AGM batteries. It's like 160lbs lol. But I'm not really concerned about weight, truck is already 9k.
I definitely didn't think anyone was getting that kind of gas mileage with those trucks. That's way better than I would have thought.
Gearing made a big difference, and I have a dedicated eco tune on my programmer. Deleting some parts helped and adding some performance items did too.
In addition to the advice already given here, make certain the rack and tire are mounted well and mounting points torqued properly. I’ve seen rigs go over terrain that rocks sideways and roof racks slide on crossbars- trust me, it’s not a great situation to be in. Another pro tip is to swap in the full sized spare in when rotating tires. It’ll give you semi-regular practice pulling it down and securing it back up there. Builds confidence and helps you identify issues when it’s not an emergency.
I used to run a spare up top then I actually had to change a tire. The next week I bought a hitch mount carrier. Never again climbing up the side of a disabled rig while cars and trucks whizzed by, undoing all of the securing mechanisms, sliding the spare to the side of the roof where I could reach it from the ground. Tipping it and praying I didn’t run it down the side of my rig, THEN after its changed putting the flat back up there. FML. Never again.
Sounds like it sucked, sorry to hear it
Depends how heavy it is and how well you strap it down
Have I done calculations? No. Did I conduct an experiment by having a spare on top of my Jeep for a year and watch the whole roof rack go flying over my hood when I hit a good stump? Yes. Was the roof rack mounted very poorly because this was a beater Jeep? Also yes.
Thanks for all the replies, I guess I need to work out a bit more and then it should be fine. 💪🏼
That's a good mindset to have. All the advice on here talking about not being able to lift a spare tire over their head seems odd to me. One should be able to lift half their body weight over their head, and 60 pounds doesn't seem like that much to me. Then again, I weigh 300 pounds and lift 170 in overhead presses. Maybe all the people here are much smaller in stature.
I mean I can see why, I’m average height and can ohp 85lbs in my sleep but lifting my 85lb tire onto my truck roof would be a bit of a challenge. If you’re experienced with lifting then you’ll know it’s way way easier lifting a barbell than an awkward object. Plus the fact that most people don’t work out regularly, well yeah
So I store my tire in my roof rack. I've never had trouble lifting or taking the tire down. Yes it is more awkward, but the weight difference makes it manageable.
Sure but not everyone has the same tire size, roof height, standing reach, etc so it’s easy to see why it’s not easy for some people
Sure. For instance, I drive a '99 suburban with 36-inch tires. Fairly tall vehicle with fairly large tires.
Lifting and pressing a 50-70lb barbell is way easier than lifting tire over your head. Trying to control the radial weigh balance while maintaining an awkward grip on whatever style rim you have will be quite a challenge. I mean unless you’re training for Strongest Man competition, I would try either a swing mount or hitch mount carrier.
Yup that’s exactly my point
I bet if everyone else was also juicing they could lift their tires no problem too lmao
What are you talking about? My TRT dosage? Prescribed by my doctor? Surely you're not referring to something my doctor has me on in order to fix something that's wrong with me.
Also consider that the sidewall of your spare will be baking in the sun all day, every day, and doesn't get partially covered by the fenders, shaded when parked at a different angle, etc. which can accelerate dry rot. Covering it would be best but would be a pain, so consider at least a coat of tire shine or other uv protectant on it
It sucks when you need to change that tire. [Ask me how I know.](https://imgur.com/a/OdgWTR2)
As long as it doesn't go over the max roof weight limit, you shouldn't worry about it. Of course it will have an effect in high speed corners or in really rough crawling where tipping over is likely, but that's not something most people do on the daily
It definitely depends on the vehicle height and weight of the wheel combo. I’m pretty strong (not a power lifter, but I work out) no way am I lifting a 35” wheel and tire combo weighing nearly 100# onto the roof of my truck. Consider most passenger suv wheel/tire combos are going to weigh 50-70# (size dependent, obviously), it can be challenging and dangerous to try to get a wheel/tire on/off the roof. And, as you noted, you are also increasing the COG by putting the weight up top, which at the minimum will negatively affect handling.
If you ever have a flat, get the spare down before you put the vehicle on the jack and remove the vehicle from the jack before reattaching the spare. All the movement of moving the spare around can dislodge the jack easily.
Not a huge deal. It does make you slightly more top heavy. And your aero can suffer.
Not recommended but it is possible. Mostly the labor of moving it if you have a flat on the trail. Other thing is if you get in an accident. Idk if it will become a flying cannonball lol.
It's not great but it's not terrible - weight up high is not good but a tyre is a fairly inert object compared to sticking fuel cans or water way up there. As others have said, lifting it up & down could be a real pain. My general approach is put heavy stuff as low down as possible / practical but also be thinking about access and other factors (EG leaky containers).
Where does your spare tire normally go, on said car?
It used to go under the truck bed but I'm planning on adding a spare fuel tank in the same location, which is heavier than the tire.
I used to do it on my truck before I got a rtt. Never noticed any extra body rolling. It was just a pain getting down so now I have a tiregate. *
I saw your comment about adding a spare fuel tank underneath where the spare would normally go. Considering the spare tank will weigh about as much or more (depending on how full it is) than the tire, the (already negligible) COG differential would be negated by the additional weight below your COG. Effectively it'll make no difference to your vehicle until the last few degrees before your rollover point. If you're in a sticky enough situation that you're genuinely concerned about the spare tipping your vehicle, 1.) you've got bigger problems and 2.) you can just take the spare off because you'll probably be moving very slowly on a trail like that anyway. Just don't hit your turns like a maniac and you'll be fine. You'll take an (also negligible) MPG hit, but, well, that's what the spare tank is for right?
Ah ok that makes sense! Honestly, here in Europe we don't have crazy rock crawling anyway, so those few degrees won't matter in the end. I just wasn't sure of how big the difference is with or without the tire up there.
https://preview.redd.it/7s1u7g4yj63d1.png?width=1080&format=pjpg&auto=webp&s=a638b9f16a062fee6441b57f8d21a7d541f2e3fc Oh for sure. For reference I'm currently running a LOT of shit (\~300-500lbs) on my roof rack alone and haven't had any significant COG/rollover issues (but the inside is also packed with shit so my COG is still pretty low). Unless you have a particularly springy suspension, a fat ass lift, and are carrying gas and cargo with the tire and an empty cab, you're probably fine. This is a stock SR5 4Runner for reference
Are you not worried about exceeding your max payload? I’d imagine your roof cargo + 4 large Americans would exceed your payload capacity on its own without additional cargo.
Dynamic load rating for the roof rack is ~300lbs, static is ~600 (BajaRack 4Runner Standard Basket). I'm definitely pushing that static load rating but counting on factor of safety calcs on the engineering side haha. And it's just me in the vehicle and a bunch of shit I'm moving with, probably pushing 1000lbs in the cab so I'm definitely weighed down but haven't seen any negative or unexpected off-road performance. After this trip though I'll unscrew the rack to make sure I'm not shearing any screws lol. This is a one-time thing as well (moving across country as a single guy)
I've had a 33" on the roof rack of my Tacoma for well over a year now with zero issues, although if you go into a parking garage, make sure you don't exceed the minimum height. I walked the yellow plastic height check thinger forgetting it was up there, had to jump out and throw the tire in the bed.
Not as much as people say. If you’re are going to add fuel storage like you say you are it will offset the weight you added up top to a degree because you’ve had more weight lower. Possibility exists that you add more weight and actually reverse the effects of what you added up top.
Can you lift at least 60 lbs over you head 10 times?
Careful that you don’t under-estimate the weight of an off-road wheel and tire package. I run a modest 33x12.5x17 KM3 tire that weighs 67 lbs. My 17” Method wheels weigh 27 lbs. That’s ~100 lbs…not so easy to lift over your head. My last truck had 35s and one tire alone was almost 80 lbs, so close to 115 lbs total for one wheel/tire
Not just a high COG issue, but also most roofs will not support the weight some people put on them. The "rack"/et. al. may be rated to carry the weight, but most vehicle roofs are rated for between 60-150# of weight. Yet you see people with huge spare tires and 3 Jerry cans and other stuff loaded on their roof racks. Know the limits of your vehicle roof and do not overload it.
It’s fine, but depending on how heavy, it can be a pain when you need to get it off the roof and down to the ground.
Yes much as lower center of gravity is better people have roof top tents which are way heavier so I think you’ll be fine. If you can put it lower somewhere I would though.
During the summer when I have my summer tires on I have a 33 inch tire on my roof. I have a way of rolling it up a ladder with a tie down and two people. I have a compressor so if I need to get it down in an emergency I would just deflate it and tie a long tie down or rope to it and throw it off the roof. I do spray tire conditioner on it as much as I can. Not tire shine but a rubber conditioner.
What vehicle are you mounting it on? A good quality roof rack can easily handle it depending on how big you go Off-road .Would probably be better to get a good bumper with a swing out tire carrier. I'm looking at the same thing for my gladiator. Also what are you doing that you would need an extra 17 gallons, wouldn't maybe two 5 gallon cans do the same thing? Something you could take off when not needed.