Tire wear

[cubrath]

I bought our 140 to train my son and a few other guys wanting their Tailwheel. We have flown it 75 hours and LOTS of landings!! Obviously the cords are showing but the inside is wearing fast. I know I could swap them mid life but is this “normal” for the 140 or should I look at the alignment?? It rolls out straight for me, not so much for my son and the other guys!!! I know my 195 wears the outside first. What’s your experience.

[4390]

Seems to be more common than not for the tires to wear uneven. I turn the tires around on the rims every annual to keep them even.

[V529]

Outside should wear more than inside.

If it "tracks straight" then you should be on the right ........track Meaning your toe in is set correctly. Have the tires already been swapped? It "looks" like the inside is worn more than the outside?

My suspicion is that while on the ground and up on the mains someone is using more down force than needed? When I bring the airplane up on the mains, I don't "pin it" (meaning I push the nose down aggressively) I hold it more or less neutral, that way when the airplane is ready to fly, it just picks up on its own.

Does this help?

[6277]

Is the wear the same on both sides? If it's only on one side, that landing gear leg may be bent. If both sides, maybe the shims are the problem, or both legs could be bent? What does it look like viewed from the front when there's no one in it?

[cubrath]

When I bought the airplane the inside of the tires were bald. It does seam that the gear is splayed wider than it should be. I’ll get some pictures today and see what you guys think.

[6643]

Actually, that tire looks to be pretty evenly worn. I've seen tires where the groove on one side was completely worn down while the other side looked new. Yours are pretty even. The bald spot could be from braking...

(upon further inspection...) it looks like the inside of the tire is worn more than the outside, indicating you have too much toe out. Interestingly, the bald spot is on the outside. Lay off the brakes! And, don't try to spin the plane around using one of the mains as a pivot point...

[cubrath]

After looking I think I do have to much toe out. If I need shims where do I get them?

[2066]

After looking I think I do have to much toe out. If I need shims where do I get them?

Ebay...item # 362976981379. Seller is in Lakeland, FL (...not me). I believe there's also another listing with one or two around Ebay...search for "Cessna 140 shims". Mac

[6597]

https://www.groveaircraft.com/accessories.html

I've got a bunch of coarse ones if you have a really bad issue but I suspect some minor shims would be more likely to help you.

[cubrath]

Realigned the gear today. Took measurements and the gear was toed out and it was pulling the gear apart when the airplane rolled forward. The shims that were in there were actually set for toe out. Took a few tries but the best results were with no shims. I flew it and it seems to roll straighter on the ground. Before when the tail came up with the mains on the ground it would swerve left. More weight on the gear, more pull. Think this was because the gear were pulling apart so hard.

Now it tracks much better. We will see how tire wear goes as well!

Picture with the big tires is when I first bought it, you can see how the gear pulled apart and the legs were always spread. No they are nice and tight when I stop and you don’t hear the scrubbing on the hangar floor like before.