hotrod150 wrote:Battson wrote:........Gradually building up to bigger rocks, still at 14psi with bead lockers (no slippage).
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From this comment & your photos, I assume you're running 26" Goodyears? How abut a description and/or photo of your "bead lockers"? Thanks.
You got it.
Here's a little "how-to" for running your Goodyear / Desser tundra tires at very low pressure, without risking the dreaded rim creep causing a flat tire. This is an unapproved mod, so it's applicable to homebuilt aircraft only.
The tire's bead is thick and strong, but relies on air pressure to hold it firm against the rim. When you run low pressure, say less than 20psi, very heavy braking torque can cause the tire to gradually slip on the rim.
To stop this happening you want to lock the bead of the tire in place, so it can't move. Some people recommend contact adhesive. One way to do this mechanically is as follows.
I know this works with Grove / Cleveland wheels, check your measurements if you try a different brand. I have tested this over and over by locking the wheels on gravel, dirt, grass, etc. There hasn't been any slippage at 14psi with a 2700lb [MTOW] aircraft.
Start with disassembled wheels, drill to hubcap screw holes right through, without removing or damaging the factory threads. There's no need to add extra holes, three is plenty.
Tap the threads right through, they are 8/32 threads on the Grove wheels. Clean up any burrs or sprigs with your countersunk reamer.
Measure the depth of the holes carefully, mine were 7/16". Select screws long enough to protrude about 1/4" into the bead of the tire (for a 26" Goodyear). For other tire types - check your bead thickness first!! You want the screws to bed-down properly into the bead, not just scratch at the surface. But the screw should not dig so deep that they could poke right through, and interfere with the inner tube!
Reassemble your wheels and tires. Careful to torque everything correctly, etc... assume you know the process back-to-front if you're working on your own aircraft. Inflate the tires.
Sharpen your measured screws to a point, without shortening them, and screw them into the tire. This shouldn't take a lot of force.
All finished (hubcap removed). Don't forget to get IA sign-off if you don't have the repairman's ticket!
Notice the "slippage" mark painted opposite the valve on the wheel-tire interface. This allows me to check for rim creep with the hubcap installed, which I do every preflight as a matter of course. I highly recommend doing this regardless of whether you have bead locks, a flat tire is no fun.
I hope that's helpful!
