Tire width difference between brands.

[Heflin]

I measured a friend's 8.00 X 6 Airhawks today and the tread width was 6". I ordered some 8.00 x 6 Goodyears and the tread width is nearly 8". I also measured some 8.50 x 6 Air Tracs and the tread width was 8". I measured the 6.00 x 6 Airhawks on my plane right now and the tread width is 4.75".


I debated spending the extra $20 per tire for the Goodyears but it looks like I got a wider footprint by doing so. I was going for a wider tire for flotation on softer soils.

[DaveF]

Thanks for posting this. I'm close to buying some 8.00 tires and thought I'd settled on the AirTrac/Hawk, but if the Goodyears are significantly wider I might reconsider. Did you measure tread width with tires inflated? How about diameter?

I'd guess sidewall flexibility has some effect on rough surface performance, too. Because of their more circular cross-section, I wonder if the AirTrac/Hawks might be softer than the Goodyears. RIght now I've got Michelin Air 7.00x6, and they've worn identically and uniformly. Michelins cost a lot more than Goodyears, though.

[Heflin]

I measured my Goodyears when I opened them and they're 6.5" inflated to 18#. Not quite the 7.95" the Goodyear site claims. Maybe I'm measuring it incorrectly. I'm measuring a straight line across the top of the tire. Diameter at 18# not on the plane is 18".

I'll give measurements after I get them mounted.

Thinkng a little more on it, I bet they all have a tire track that's wider when the tire bulges out. A curved measurement across the top of the Goodyears gives nearly 8". Probably about what the footprint is under a load.

[Joe Moilanen]

Thanks for posting this. I'm close to buying some 8.00 tires and thought I'd settled on the AirTrac/Hawk, but if the Goodyears are significantly wider I might reconsider. Did you measure tread width with tires inflated? How about diameter?

I'd guess sidewall flexibility has some effect on rough surface performance, too. Because of their more circular cross-section, I wonder if the AirTrac/Hawks might be softer than the Goodyears. RIght now I've got Michelin Air 7.00x6, and they've worn identically and uniformly. Michelins cost a lot more than Goodyears, though.

You may have to make a spacer disc to go between your brake disc and inner wheel half to keep you caliper from rubbing on your tire, I did...

Joe

[Heflin]

On the 8.00's, Joe?

[swixtt]

i'm running GY 8.50 and mine rub... i've got a spacer ring i need to add to fix this. on the list of things to modify after getting her.

[Heflin]

I don't think my 800's are gonna rub. Not mounted yet but I tightened a spare caliper down and they clear. Maybe yall were only talking about 850's

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[swixtt]

you'll be just fine!

[Heflin]

With or without me in it causing the left side to be even fatter?

[Joe Moilanen]

On the 8.00's, Joe?

Mine rubbed just slightly with Airtracs Heflin, so I installed a 1/4" spacer ring.

Funny story how I got the spacer rings. At this place that I was working about 50 miles from my house I kept driving by this short 1200' airstrip out in the woods. One day, I seen the owner outside and decided to stop and BS about airplanes. He had a PA-11 in his hangar and i told him what I had. He went on to tell me about his friend that flew his 170 in to visit him several years ago, had one too many beers and decided to leave his plane there overnight. During the night, the neighbors bull got out and horned the elevator. He said: "We replaced the elevator and <Phil> flew home the next day". The name Phil spiked my interest as the owner before the one that I bought it from was named Phil. Sure 'nuf, it was my plane that got horned!! He proceeded to give me the wrinkled elevator for memorabilia that was hanging on the wall. I was then looking at his PA-11 that had 800 tires on it. Noticing the amount of clearance that he had between the caliper and tire, I asked him if he put spacers in because mine were slightly rubbing on my tires. He said: "Just a minute", and walked into his messy hanger and grabbed a pair of spacers off a nail on the wall and said "here you go!" I told him that they looked like they would fit. He said: "I know they will, they came off from your airplane!!" Small world...

Perhaps it is just the Airtracs that will rub, maybe someone will chime in with some info on a brand that won't. I actually ran mine without spacers for awhile but they did just barely rub once in a while, probably just when they flexed.

Joe

[DaveF]

Are these spacers authentic Cleveland parts or homemade?

[Joe Moilanen]

Are these spacers authentic Cleveland parts or homemade?

Mine were homemade. I would make them as thin as you can get away with. If they are spaced out too far, the anchor pins on the caliper won't be going into their holes very far.

Joe

[Heflin]

I'll check to see if these rub. If not, the $20 higher tire cost might pay for not having to make and install spacers.

[Heflin]

What air pressure are y'all with 800's running? I'll rarely be at gross. Usually around 1600-1800.

[Joe Moilanen]

24#'s