The first post in this thread is of a -6, and I have a 6A that is 99% complete. The alignment of the gear legs for the -6A was called for in the initial fitting of the wings, as the gear leg sockets are matched drilled to the wing spars and cabin side frame structures.
The -6 gear legs are inserted into leg sockets that are welded / attached to the engine mount. The wheel alignment is controlled by the rotational position of the gear leg in the leg socket (as it is for the -6A).
The "normal" , on-the-ground position of the main wheels for the RV-6 series a/c has the top portion of the wheel tilted outboard from the a/c. In flight,with the weight off of the gear, it is more so. On the ground, this will allow more wear on the outside portion of the tire tread, and I believe you find this to be normal and expected. Grass field operations tend to minimize this wear characteristic. There is no real fix for this "normal" condition, but periodic flipping of the tire on the rim will put the "worn" section on the inside of the rim and the "less-worn" on the outside of the rim.
If the tire wear is only on the outside edge of each tire, and both the left and right tires show equal wear, well then, it sounds like the alignment is consistent, and the same, for each wheel. That's good. And it sounds like that is your impression as the a/c does not "pull" to either side with ground taxi conditions.
A question on landing techniques: do you routenly grease the landings by skimming along the runway? Or, is is a firm and deliberate plant?? It seems that skimming would allow the wheels to just kiss the surface and allow tire outside edge rubber to be worn away. A plant may minimize this. Also, with the kiss technique, the geometry angle of tire alignment-to-flight path direction may be changing as more weight is slowly transferred to the wheels as air speed decreases.
So how can you determine if each wheel is tracking "straight", or if both are pulling to one side, but in equal but opposite amounts? A technique that can be used to see what the tire alignment is actually doing is to try the following:
1. use two appropriately sized sheets of tin, aluminum, whatever.
2. place one sheet under each tire, with full a/c weight on the gear
3. secure the a/c by whatever means to prevent the a/c from moving
4. simultaneously, pull each sheet rearward with the same force and speed.
5. the wheel should be free to rotate as the sheet is pulled
If the sheets can be pulled straight back, the alignment is parallel to the a/c center line. If the sheets rotate, or move to one side or the other, then the alignment is such that it is forcing the sheet to one side.
Hope this helps.
