How to mount a gravity casing tire without a fight, shown on a Grappler Radial.
A gravity casing tire is stiff on purpose. Two plies and apex inserts in each sidewall are what keep the tire on the rim when you're getting it wrong at speed. That same stiffness is what makes the tire fight you on the workbench.
The short version. Warm the tire, lubricate the bead, keep the fitted bead pushed down into the center channel of the rim, and lever only the last section in, in small bites. It's a technique, and it works on every gravity casing we make.
Before you start
The rim should already be taped and the valve fitted. The wheel in the video is. If yours is not, do both now, because neither is possible once the tire is on.
Two tricks worth knowing
Warm the tire. Leave it somewhere warm for a while before you start. A car, a truck bed on a sunny day, anywhere above room temperature. Warm rubber is more pliable, and a cold gravity casing barely flexes at all.
Lubricate the bead. Spray glass cleaner on the rim and on the tire bead. It lets the bead slide into the rim channel instead of gripping halfway around.
Neither is essential. Both make the job easier.
Installing the tire
1. Check the direction. The rotation arrow is printed on the sidewall. Confirm it before anything else, because a tire installed backwards has to come off again.
2. Line up the graphics. Put them on the non-drive side, the disc side of the wheel, and line them up so the wheel looks right. This is cosmetic. Do it anyway, because you cannot fix it later without starting over.
3. Set the first bead. Work the bead over the rim by hand, all the way around. If the last section will not go, use a tire lever. Take small bites with the lever rather than levering a long section at once, which is how rim tape gets torn.
4. Start the second bead in the center channel. Every rim has a channel down the middle, and it is deeper than the bead seat. Push the part of the tire you have already fitted down into it. That slack is what gives you room to finish. Without it, the last section has no bead length left to stretch over the rim.
5. Work around to the last section. Hand pressure, both thumbs, moving around the tire until only a short length is left sitting outside the rim.
6. Lever the last section in. Take your second lever, short bites, and the bead drops in.
A flat work surface helps for the second bead.
Then seal it
Add sealant through the valve and inflate. Our Tire Plasma sealant seals MTB holes up to 8mm instantly, so be generous with it. The tire lever and plug repair kit covers the job itself, plus the plugs for a backup plan.
Works for standard casings too
The tire in the video is a Grappler Radial, but the method is the same for our other casings.
