29 in AK Bush Wheel to 21 in Tundra

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29 in AK Bush Wheel to 21 in Tundra

Postby HS-JAT » Sat Aug 01, 2015 10:47 pm

First off, I am all about looking cool.

That said, there are far too many performance (and price) advantages to not ignore by ditching the 29inch AK Bush wheels in favor of smaller tires on the Highlander.

I had to see it, and feel it to believe it myself. So I bought two 21 inch tundras from Dresser tire ($175 ea with HD tubes), and bought an extra pair of MATCO 6 in wheels ($220).

I was truly shocked at how much better the plane climbs. 12-15 deg pitch up at 55mph single pilot. I was at 300ft AGL by the end of my short grass strip. I think those big wheels do horrible things to the aerodynamics of the wing and tail in a climb, not to mention the drag factor.

5-10kts cruise ground speed improvement easy!

Pros of 21" Tires
Cost $350 vs $2500
A tire with tread (Better in rain and paved runways)
Super braking improvement
Much Better Climb Performance
Much Better Cruise Performance
Better Ground Visibility from lowered front end
A much better landing attitude consistent with most other taildraggers. Always thought the sitting angle of the Highlander was much too high for the short distance from mains to tailwheel.
Vastly improved ground handling stability. Aircraft does not wallow around on the big balloons. Feels much more solid.
Can handle most unimproved field situations. I have always said that plenty of aircraft have landed in crappy places without AK bush wheels.

Cons of 21" Tires
They might not look as "Cool" as AK Bush wheels
Might not be able to Water ski or land on the side of a mountain or stream bed.
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Re: 29 in AK Bush Wheel to 21 in Tundra

Postby AV8R Paul » Mon Aug 03, 2015 12:08 pm

I am partiAl to the Dresser 21 inch Smoothies. I had my Kitfox SLSA, converted fro a Tricycle Gear to a Tail dragger. I had Kitfox put a set on my plane as part of the conversion, they are great. I landed on Blacks Field one of the roughest grass / dirt / Rock fields I have ever landed on. I have flown several of the Idaho back country airports none as rough as Blacks Field. The Dresser Smoothies were more than adequate. I picked up 5 to 10 mph going fro the TriGear to the tail dragger., even with the larger tires. You may want to consider them in the future.
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Re: 29 in AK Bush Wheel to 21 in Tundra

Postby gkremers » Mon Aug 03, 2015 8:31 pm

When I build my Highlander I loved the look of the 29" AK Bush tires. Living on a paved runway with no grass option they were just not going to work long term. I bought some Air Trac 8.50 x 6 tires, they have a diameter of 20.5 inches and seem to fit the plane perfectly. Do you guys have the weight of the Dresser tires?

Thanks
Gary

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Re: 29 in AK Bush Wheel to 21 in Tundra

Postby danerazz » Mon Aug 03, 2015 9:42 pm

Desser's website says 8.5lbs for a smooth one, 11lbs for the threaded version.
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Re: 29 in AK Bush Wheel to 21 in Tundra

Postby HS-JAT » Tue Aug 04, 2015 7:03 am

Personally I think the threaded is the safer way to go for all conditions.

I am just excited about the drastic change in performance. With improved climb performance I can now give it a bit more prop angle towards cruise performance. Looking forward that result.
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Re: 29 in AK Bush Wheel to 21 in Tundra

Postby gkremers » Tue Aug 04, 2015 7:13 am

The 8.50 x 6 Air Trac's I have are grooved but weigh 16lbs each, looks like the Dresser grooved tire is 11lbs. I'll need to look into them when I need replacements

Good info

Thanks
Gary
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Re: 29 in AK Bush Wheel to 21 in Tundra

Postby danerazz » Tue Aug 04, 2015 8:14 am

The air tracs are 6 ply, the Desser tundras are 4 ply. That is probably where most of the weight savings are, they are just a lighter construction. The 4 ply is more suited for our light, slow planes. 6 ply is serious overkill but much more commonly available.

Incidentally, that does not mean they have 6 or 4 plies, it just means they are constructed with equivalent strength of said plies. The ply rating is an indication of how much load they can handle, and 4 is definitely enough for our plane weights and the low air pressures they run.
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Re: 29 in AK Bush Wheel to 21 in Tundra

Postby AV8R Paul » Tue Aug 04, 2015 12:04 pm

The Desser 850-6-4Ply tires "Our "Pillow Soft" 22 x 8.50-6 4 Ply stands 22 inches tall and weighs in "featherlight" at under 10 lbs. Compare that to a standard 850-6 6 Ply which average 15 lbs. each.”
http://www.desser.com/Aircraft-Tires-an ... -4-PLY.asp
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Re: 29 in AK Bush Wheel to 21 in Tundra

Postby av8rps » Tue Aug 04, 2015 5:00 pm

Yeah, I agree that if logic prevails, the smaller tires generally make more sense than do the 29 inch alaskan bush wheels. Unless of course you want to land in some really knarly areas that the smaller tires just can't handle.

AND, hanging a 15 ft set of amphib floats that weigh 250 lbs from the bottom of your Highlander makes even less sense. Unless of course you want to visit special places that no tire, regardless of size, will take you.

Yet I love a Highlander on big tires, and also on floats. Either big tires or floats will make your Highlander an ultimate adventure machine. Very few aircraft will do that better than a Highlander, as it was designed to be an incredible off-airport machine. That's the same reason a Vans RV 12, a Sting, a Breezer, a Lightning, etc, etc do almost nothing for me. I love the versatilty of the Highlander, in spite of its other limitations compared to the faster and sleeker choices.

So yes, we can most certainly operate our Highlanders more efficently on the smaller tires. But for the ultimate cool factor one can enjoy with their airplane, the bigger tires just make the Highlander come into its own.

And I just have to say this in closing; I can't tell you how many times I have watched your orange and white Highlander on video with the big tires flying over that beautiful scenery of Thailand. Even my wife has commented about how cool your plane is. So I'm not going to tell her you put smaller tires on... :wink:
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Re: 29 in AK Bush Wheel to 21 in Tundra

Postby xpflyr » Tue Aug 04, 2015 5:05 pm

Why not consider these;
http://www.aircraftsupply.com/260k61-1.html
26 inch for $669 and they fit the standard rim. You should still get the brake upgrade.
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Re: 29 in AK Bush Wheel to 21 in Tundra

Postby AV8R Paul » Tue Aug 04, 2015 9:11 pm

These look nice. I personally thing the 29” are a little too large. I have bookmarked these for a future purchase.
GOODYEAR SMOOTH TUBELESS TYPE TIRE - 26X10.5-6 6 PLY $637 per at Aircraft Spruce.


[quote=“xpflyr”]Why not consider these;
http://www.aircraftsupply.com/260k61-1.html
26 inch for $669 and they fit the standard rim. You should still get the brake upgrade.[/quote]
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Re: 29 in AK Bush Wheel to 21 in Tundra

Postby SheepdogRD » Tue Aug 04, 2015 11:54 pm

Paul Z wrote:These look nice. I personally thing the 29” are a little too large. I have bookmarked these for a future purchase.
GOODYEAR SMOOTH TUBELESS TYPE TIRE - 26X10.5-6 6 PLY $637 per at Aircraft Spruce.

You may want to consider these 27x10 tundra tires from Desser Tire:

http://www.desser.com/aircraft-tires-and-tubes/2710-8.asp

They're 2 pounds lighter and $242 less expensive, and that's per tire. They go on 8-inch rims. The cost savings on one tire would buy the rims.
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Re: 29 in AK Bush Wheel to 21 in Tundra

Postby HS-JAT » Wed Aug 05, 2015 12:13 am

av8rps wrote:Yeah, I agree that if logic prevails, the smaller tires generally make more sense than do the 29 inch alaskan bush wheels. Unless of course you want to land in some really knarly areas that the smaller tires just can't handle.

AND, hanging a 15 ft set of amphib floats that weigh 250 lbs from the bottom of your Highlander makes even less sense. Unless of course you want to visit special places that no tire, regardless of size, will take you.

Yet I love a Highlander on big tires, and also on floats. Either big tires or floats will make your Highlander an ultimate adventure machine. Very few aircraft will do that better than a Highlander, as it was designed to be an incredible off-airport machine. That's the same reason a Vans RV 12, a Sting, a Breezer, a Lightning, etc, etc do almost nothing for me. I love the versatilty of the Highlander, in spite of its other limitations compared to the faster and sleeker choices.

So yes, we can most certainly operate our Highlanders more efficently on the smaller tires. But for the ultimate cool factor one can enjoy with their airplane, the bigger tires just make the Highlander come into its own.

And I just have to say this in closing; I can't tell you how many times I have watched your orange and white Highlander on video with the big tires flying over that beautiful scenery of Thailand. Even my wife has commented about how cool your plane is. So I'm not going to tell her you put smaller tires on... :wink:


Thank you sir for the Video remarks. I have not been able to do much flying the past year, but I promise some stellar Thailand scenery vids this fall and winter even with the small tires!

In Thailand the smaller tires are a matter a practicality and following the rules. Unlike in Aviation free countries, one can not just go land where ever they want in Thailand. It has to be an approved and registered airfield. Although they can be quite small, rough, and challenging, they still have to be approved and legal. Landing on the beach or on the side of a mountain is a no-go. That is not to say that you ARE allowed to get away with some things that would be a No-go in other countries. Noise and low flying complaints don't exist, and you could probably get away with a lot of things as long as you don't crash :)

So if I can get a bit better cruise and climb performance, but still land on grass strips without a problem, I am good. I think that if a Highlander owner had a set of both small and big set up, he could change as the mission dictates. Change out takes less than 20-30 minutes. Hell one could even carry the tires in the back cargo area if he wanted to.

There also might be a cultural thing with Americans and big tires, as many people from other countries are not so enthralled with them :) Been asked many times when I am going to put on some smaller tires.
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Re: 29 in AK Bush Wheel to 21 in Tundra

Postby bluemax » Wed Aug 05, 2015 9:09 am

Paul Z wrote:These look nice. I personally thing the 29” are a little too large. I have bookmarked these for a future purchase.
GOODYEAR SMOOTH TUBELESS TYPE TIRE - 26X10.5-6 6 PLY $637 per at Aircraft Spruce.


[quote=“xpflyr”]Why not consider these;
http://www.aircraftsupply.com/260k61-1.html
26 inch for $669 and they fit the standard rim. You should still get the brake upgrade.
[/quote]

When I was talking tires with Troy years ago, he did not exactly give a glowing endorsement of the 26" Goodyears. He said that they are prone to spin on the rims ( I assume when braking? ), requiring that they be screwed to the wheels. I think Goodyear makes these for the blimps?
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Re: 29 in AK Bush Wheel to 21 in Tundra

Postby gkremers » Thu Aug 06, 2015 3:21 pm

Richard,
They look good if you don't want treads.

Gary
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