Sport Pilot Talk

My right main tire is worn down on the inside edge but the left one looks OK. Should I replace both or just the worn one?

No need to replace a good tire, JJ. Just make sure you get the same type of tire that's on the other side (don't mix dissimilar tires). In fact, for an SLSA, ASTM rules consider changing tire makes and types to be a modification requiring an LoA, so if you don't have one, you are required to buy what the manufacturer used.

Both of my SportStars came from the factory with flimsy Cheng Shin tires. I prefer something more robust, so requested and received manufacturer's authorization to go to Michelin. Those were considerably heavier than the originals, so I did have to recompute empty weight and EWCG, and carry revised wt/bal documents in the planes. (The LoAs always say revise wt/bal if change is significant).

A couple of other things: always use new tunes whenever you change a tire. They cost less than what you would spend on labor if you have to pull and split the wheel, replace a tube, and rebalance the wheel a few weeks later! Align the red dot on the tire with the valve stem to equalize weights. Then,, always balance the wheel (you can get the little stick-on weights in a bike shop). I use a motorcycle wheel balancer from Harbor Freight - very inexpensive.

Finally, on all the planes with spring arm main landing gear (composite or aluminum), tires tend to wear on the inside treads first (that's because the gear leg flexes when you put weight on it, so the insides wear while taxiing). If there are no cords showing, you can pull and split a wheel, reverse the tire on it, and keep using the old tire until the other side wears down.

Rotating the tire on the rim is a good idea if it is not to worn. If you are going to do it yourself rotating the tire is a good idea. If you are paying someone to do it it may not be a cost effective. You will have to factor how much more life the tire has if rotated, the labor involved, and the cost of the new tire and tube.

Thank you both for the great information.

My annual condition inspection is due by May 31 and I worry that rotating might not be acceptable to the inspector. I guess I could ask but I do have to wonder how much it will actually save me since I can't do it myself.

For most LSAs, the condition inspection checklist includes pulling the wheels, checking the brake pads, and repacking the wheel bearings. Since the wheels will be off anyway, this is the ideal time to rotate the tires. By all means, ask the inspector to do this for you.