Tailwheel a *****cat on grass but a wild animal on pavement

[avidflyer]

If you jack up both tires at the same time, put some masking tape on the center of the tires, spin them with a pen held solidly on something so it doesn't move around against the tire, you will get a fine line that is exactly consistant on the tire. (not affected by sidewall bulges and such) Do that on both tires and then you con measure between the lines on both tires. To see which gear leg is more out of whack, you can tie a string on the tailwheel spring, and pull it forward down the center of the plane at the same hight as the axles. With the string tied off ahead of the tires, Measure to the string and you will see how front and back of each wheel compares. Hope I explained it well enough so it makes sense. I'm about to do it again on the Kitfox 1, I'll have to take pictures. Jim Chuk

[avidflyer]

I rigged up the thing I was talking about on the Kitfox 1 today, and snapped some pics while I was doing it. Found out that the left wheel has about
3/8" toein and the right side has none. I ended up drawing a pencil line on that cross 2x8, and put a nail on the line front and back of the tires. Making a mark on the tape and measuring it off the front nail, then rotating the tire so you can measure to that same mark off the rear nail should be very accurate. At least that's my story, and so far I'm sticking to it, although it is slightly modified from my earlier post. ;-) Jim Chuk

[jiott]

I don't want to complicate things too much here, but there are some differing opinions on setting the toe-in with weight on the wheels or not. I did mine like avidflyer with weight on the wheels (suspension) so it tracks straight after landing and weight is mostly on the wheels. I have had no ground handling problems whatsoever for 3 years now. However, there is a school of thought that it should be done with no weight on the suspension, simulating the first instant of touchdown. To me that makes little sense because nearly all ground handling/looping problems occur later on in the rollout. FYI, the toe-in/out measurements WILL be different with or without weight on the suspension.

[jiott]

By the way, you can jack up one tire at a time to get the marks on them by spinning, then set them back down on the ground to do the toe-in/out measurements. I snapped a chalkline in the floor for the plane centerline. Many ways to get the same job done.