Tire Maintenance

I had several issues to resolve on my Vans RV-3B:

• The right main gear shimmies.
• Tire Pressure constantly leaking.
• Tires wearing on the outside and need rotated.

I figured I w0uld take a stab at resolving these issues.

The shimmy problem will probably take a couple of tries to resolve.   It can be really bad when the tire pressure is high – slight when pressure is low.  I generally try to keep the pressure around 23 psi but that is near impossible. I have the old style inner tubes which leak constantly and I am too lazy to remove the wheel pants as often as I should (to add air).

The easy answer to the leaking tubes is to order and install a set of the better LeakGuard tubes.  However; $55 for one inner tube should, in my opinion, be considered robbery.  So, an option was required.  I’ve used green Slime  (http://www.slime.com/) in previous aircraft tires and figured I’d give it a shot in these. Cost: $9.00.  I didn’t add it to the tubes until after balancing (below).  I have no idea how this stuff distributes itself so it could render my balance work a waste – or make it better – or worse.  Who knows…

Rotating the tires is not as easy as just swapping right to left. This is because the brake disk is attached to the wheel so there is only one way to install them.  Moving the right wheel to the left side causes the worn side of the tire to still be on the outside.  The only way to do this is to split the wheel, flip the tire around, and reassemble.  So, that’s what I did.  I am thinking that if the shimmy moves to the left side then the problem is the tire (that was previously on the right side) – maybe out of round or something.

I wanted to balance the tires in an attempt to eliminate the shimmy problem.  This is a free and easy change so worth a shot.  I barrowed a friends “balancer” which is basically just a mandrel that fits the wheels and then sits on a smooth, level surface. The wheel/tire is then free to rotate which allows gravity to do it’s work so the heavy part of the wheel/tire is at the bottom. No high tech “spin balancing” done here!! 🙂  The first wheel was easy. There are three bolts that hold the two wheel halves together. One of them was at the lightest part of the wheel so I replaced it with a slightly longer bolt and added a couple washers.  Perfectly balanced.  The second wheel/tire was a bit more of a headache.  I tried spinning the tire around on the wheel to find a balance and finally got something close – then used the longer bolt trick again.

I’ll report back on the results of these changes.