Mounting 6 inch on 7.1 inch wheel

Good afternoon folks,

Anyone have any tricks to mount 6 inchers on a wider wheel? I’m freeing up the rear of the kart and it’s not working with ratchet straps and a tire strap. Tires are Hoosier R70’s on Douglas LV’s


If you’re feeling frisky, some starting fluid sprayed around the bead and then lighting it on fire usually works. I’m not liable for you losing your eyebrows though.

Are you heating the tire up and using a mounting lubricant?

Hey TJ,

We are using both heat and lube. I’m not too sure why it’s so difficult. It’s quite common so I’m missing something

Get a real metal tire band and crank it down so the air pushes out the sidewalls.

DO NOT use a ratchet strap. That’s insanely stupid. If it snaps, it’ll sling the ratchet part God knows where. I’ve seen it happen.

Hi Matt,

I should have been more clear. We tried ratchet straps and a tire band (I said tire strap). It did not work so I switched to a 6 inch wheel, made a super chain, max caster and dropped the frame.

Crank that tire band all the way down? Get lube on the tire bead, inside and out, grab a clip on chuck, stand back and let er eat. I’ve used 120-140 psi a few times on stubborn tires.

Any chance that anyone is going to the showdown at PKRA from 12-14th? I still cannot get this to work. The reason that I am focused on this is PKRA has their surface redone and evidently, it’s grippy as hell. I know that I’ll be battling an over gripped rear.

Is the problem getting the tire to the rim to start the seal or getting it to pop on the bead?

Hey Derek,

It’s getting the seal started. I crank the tire band all the way down but it lets too much air past the bead

Ah, yes. This can be tricky depending on the wheel used. Some wheels have a lot bigger ledge than others. An old gold cup trick is to take tires off wheels, cut some dowels from wood and put them inside your tire for a few days (ends of dowels pushing the beads out). About 3-4 per tire usually does the trick. This will allow the tire to take a wider set in its relaxed state. It helps if you have some sunlight to set them outside while you are doing this too. Then, take dowels out, put them back on the wheels and the beads will be closer to catching. You may need to do it in two stages, starting with a shorter dowel and then switching to a wider one.

Where there is a will there is a way. We used to stretch 6" tires on 9" wheels when we were street racing. Hope this helps. Good luck!!


Coming from a tire shop back in my youth, there were two things we did to mount skinny tires on wide wheels.

Warning, this should not be performed by minors and I take no responsibility for your safety using this method!

Like Derek mentioned, the biggest hurdle is getting the side walls to balloon out enough to meet the sealing surface of the rim. First step is to remove the valve core from the valve stem. This allows a greater volume of air to enter the tire. If that does not work, you can try Ether. Ether is very volatile and will expand rapidly when ignited. Second benefit is that the heat from the ensuing explosion (yes, I said explosion), is transferred into the tire, softening the rubber and making it a littler easier on the second attempt. An aerosol can of Ether can be found at most auto part stores labeled as Starting Fluid. A little goes a long way with this stuff, so don’t go emptying half a can on a single tire, especially a small kart tire. We typically did this on a tire machine that had a locking air line on the valve stem and a remote pedal to trigger the air. It took a little timing between shooting the ether into the tire, lighting it by throwing a match from a few feet away and triggering the air line to continue filling the tire once it expanded to meet the sealing surface.

Here is the basic concept, but with ether you need less fluid and it evaporates more quickly for a better stoichiometric ratio for complete combustion. :grin:

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The guy is walking by, pointing, and saying “Hey, I think you might be over infla…”
I hope everyone was OK.

He got Project Orion’d. This made me think of the explosion as propulsion idea that Freeman Dyson played around with during the early days of the Cold War. The idea was to use small yield nukes to propel a vehicle long distances.

This is a conventional explosives test I believe. This has no karting application that I know of but could be useful to make sure no one tries to bump draft you.

Hence why I stated, " a little goes a long way"! That was an example of too much fuel. The other reason in the video I linked they stand the tire on end is because a tire laying flat can get thrown into the air as illustrated in the later example.

Done properly, it is effective. Remember, better too little fuel and several attempts using slightly more, than too much fuel and you lose a limb.

Why not just bring them to a tire shop to get mounted

Did that when I first started, had no clue what I was doing, the first time they were really nice, mounted them for free, second time (different staff) the charged me $75 for 4 tires which I think is a little ridiculous. After hundreds of tire changes I’ve finally got to the point where it’s second nature.

But to your point, in your case it may be better to go to a tire shop, even if they charge you it would most likely be less than the cost of new rims + you wouldn’t have to be frustrated trying to get them on the rims.

It’s not cheap but I bet one could make some coin on race days mounting tires.

I’ve already bought that bad boy. It works great but I’ve not been able to get a single side beaded to start.

I should elaborate. My idea is to seat one side of the bead, use the tire band and then pop the other bead on

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What kind/brand of wheel are you mounting these on?