tundra tire questions?

[westwind]

delete......

[Cubus Maximus]

You can also look at Gar Aero 10 inch wheels/tires or Dave Calkins favorite Cub mod, the Mickey Thompson drag slicks. :D

http://www.supercub.org/gallery/view_photo.php?set_albumName=supercubs&id=bfn

http://www.supercub.org/gallery/view_photo.php?set_albumName=supercubs&id=beu

[SJ]

I felt the 31" decreased my TO roll due to the angle of attack. I had goodyears before.

sj

[westwind]

delete.........

[Big AK]

Of course there is a ground handling difference that is noticable. The ability to roll over obstacles and through soft spots is also noticed.

The idea that the three-point AOA increase will hurt your takeoff performance by increasing take-off roll drag is outdated. I have had this argument before with a "notable" Cub guru. It was in reference to the 3" and 6" extended gear legs.

By-the-way, I don't recall ever hearing about Dave Calkins liking the Mickey Thompson slicks. Did Mickey Thompson actually make slicks?

Are you messing with me Maximus??

DMC

[Cubus Maximus]

To answer that in short - Yes :D


(Actually I was expecting DC to be looking for his bear rifle and making threatening noises by now. The fact that alls quiet on the western front is worrisome.)

(just had a guy here put M/T's on a PA-12. Went from Mr. 7:00x6 to these things. We are all somewhat amazed at this dramatic attitude change and specialists are being consulted. 8)

[StPat]

I want to hear more about the slicks.
Patrick

[cubdriver]

I felt the 31" decreased my TO roll due to the angle of attack. I had goodyears before.

sj

I guess you lost me here. So, you take off in the three point attitude??? And it decreases your TO roll???

[Bob Breeden]

New Guy,

This thread is getting humorous!

If you use 26 inch tires, get 3 inch longer gear legs. You will appreciate this for angle of attack, so that you aren't banging your tail on takeoff rotation (and having to wait and take off faster) and on landing for the same reason. Especially if you use VG's, which I personally recommend.

With 31's you may not need longer legs. They couldn't hurt, though. I will leave that answer up to the guys that run those bigger tires.

As to Gar-Aero, I had these on my former 185. There they are perfect, because the larger wheel rim, which is epoxied to your original rim, helps spread out the load. On a Cub the extra metal rims cut into cushioning that could be in the form of a flexible tire instead of stiff rim. Dave Calkins, if the allegation is correct, has a bigger tire on the Gar-Aero rims, and it looks like a softer set up for a Cub. Otherwise I would use something with more cushioning on regular 6 inch rims. Even 26's have a reasonable amount of vertical sidewall to absorb your stuff.

I have a question for the guys using slicks on Gar-Aero's. In what terrain are they superior to Bushwheels?

New Guy, to answer your question in your second post, some if not all guys accelerate with the tail at least partially up. This takes out some or all angle of attack. The tail comes up so quick that the groundroll would be equal from a wing/fuselage drag basis with any height gear or tire. The coefficient of friction with the various tires is another matter - and psi counts.

Bob

[diggler]

diggler

[PA12driver]

New guy,

This topic has been beat to death, but I think Bob B. had the most inclusive post. The biggest benifit to 'real tundra tires' will be the absorbsion of the rough stuff. The New 31" radials will definetly roll with less resistance then the older bias tires of 'any manufacture'. I think you will find that the shortest take off roll in any (realitively) stock cub will be if you get the tail up as soon as possible to lessen the drag of the HAO and at the optimum time grab a handful of flaps and rotate! bleed off the flaps to 1 notch for best climb performance over any obstacle. The 'taller tires, and extended gear coupled with VG's will definetly aide in getting airborne sooner. (It does take practice) to make much difference, cause if you jerk her off to early you won't fly!

The benifit of 6" extended gear is a great advantage to the PA12 with a lesser AOI. The difference in take-off roll has been for me about 20% (still about 25-30 ft longer then a SC) with about the same weight and power.

Hope this helps

Tim

[StewartB]

Bob,
Bushwheels are the tire of choice on 180/185's also. Gar's were a compromise. Cessna's like soft tires, too. Radial 29's are going on my 180 in a day or two. I'll let you know the results.
SB

[westwind]

delete.........

[PA12driver]

SB,

I flew a 53 180 around the state for nearly 20 years (N2865A) before they had Tundra tires, (did put a set of 26" all purpose tires on it for a little while??? I later had a 77 185 (N7273H) and flew it into some really rough ****! (Ask Rod Russell about the trip to get his 170)?? I used Gar Aero's cause they were the only legal tire/wheel combination at the time. You are right they were to stiff, even when ground down. the New radials would be the cat's meow! (better yet the 35's Bill is working on!

Tim

[cubdrvr]

Yeah.......how did we all survive with the old 8:00 X4's??

I have a question? Is there any noticable difference between the 29 and 31 Bushwheels? Please nobody say 2" :P

[PA12driver]

Cubdrvr,

I am to understand the 31's were not originally approved for "heavier" planes, that is why there was continued production of the 29's? (Wup alittle help here??)

The 31 inch "radials" grow in height considerbly! I have measured them to be in excess of 33" so yes they do add ground clearance and on a PA12 they raise the AOA considerably at rotation. (I haven't personally tested for noticable performance gain with a PA18 (little help here 18 guys)

PS: I am told by some sources that 2" does make a difference???

Tim

[StewartB]

Tim,
26's and 29's are rated to 1800# per tire. 31's only to 1500#. So, with my 180 grossing at 3190, or a 185 even higher, 29's are indicated. I park near a 2850# 180 with 31's. He loves 'em.
SB

[FlipFlop]

I want to hear more about the slicks.
Patrick

Is this the STC for the slicks?...

Installation of SWS-11000 Tundra tires, wheels, and hubs.
STC Number: SA2338NM
Description: Installation of SWS-11000 Tundra tires, wheels, and hubs.
Status: 08/01/1986
ACO: CE-AK
STC Holder: Richard J Schneider
Address: 20 Malaspina Drive Eagle River, AK, , 99577
Manufacturer: PIPER
Models (TC): PA-18 (1A2), PA-18-125 (Army L-21A) (1A2), PA-18-135 (Army L-21B) (1A2), PA-18-150 (1A2), PA-18105 (Special) (1A2), PA-18A (1A2), PA-18A-135 (1A2), PA-18A-150 (1A2), PA-18AS-125 (1A2), PA-18AS-135 (1A2), PA-18AS-150 (1A2), PA-18S (1A2), PA-18S-105 (Special) (1A2), PA-18S-125 (1A2), PA-18S-135 (1A2), PA-18S-150 (1A2)

[cobblemaster]

Could somebody tell me if cooling test were done with Bushwheels when they got their stc?

[StewartB]

I don't understand why they'd consider a cooling test. The rated output of the engine isn't affected, and engine operation doesn't change.
SB

[cobblemaster]

Is there no increased drag?

[nanook]

Cuby: That is the racing slicks STC

[nanook]

PA-12 Driver: Before tundra tires? You don't remember the Goodyears with the white letters and the little steel springs screwed sideways into the tread for traction??...

[nanook]

Guys: the GAR-Aero 3 or 4 ply 29" is a soft tire. The mistake people make is putting the 8 or 10 ply tires on and wondering why the tire is so hard, not to mention heavier.

[Bob Breeden]

SB,

Yeah, I wonder how you like your new 29's on your 180.

What do you run on your Cub?

Bob

[hottshot]

Tim--

That was one of the reasons for bringing the 29's back into production as well as the 26's, they are bolth rated for the HIGHER Gross A/C. Befor we did the STC and the up-gross the 26" and 29" tires were bolth almost cut from our line of tires to a build on order status now we keep at least 3 sets of each in stock at all times but the 31's are still our #1 tire

SB--

Do you work in advertising? :lol: Keep up the good work!!


Wup

[StewartB]

Bob,
The 12 has 31's. The 12 is 6 months from flying, though. I'll let you know exactly how I like the 29's vs. 26" Goodyears on my heavy plane. It's sandbar season up here, so I'll be able to do some real testing.

Wup,
Good stuff sells itself. I'm just a happy customer. I'll be sending some pictures soon.

SB

[hottshot]

SB--

Great!! Keep'em comeing getting new pictures out of people is kinda like pullen teeth some times!!

Wup

[cubdriver]

Guys: the GAR-Aero 3 or 4 ply 29" is a soft tire. The mistake people make is putting the 8 or 10 ply tires on and wondering why the tire is so hard, not to mention heavier.

I have used the shaved down 29" 3 plys for many years. They are soft and are a pound each lighter than 30" Airstreaks, mounted on the same type wheels. I figure I can operate on rocks 2" or 3" smaller than the Airstreak guys.

Also, field reparibility on the Airstreaks and Bushwheels is dificult but is a snap with the GAR's.

Also, the entire GAR set up, cost about 1/3 the price of the other two.

I will probably move up to the Bushwheels if these darn things ever wear out. 18 years of service and still look fine.

[slowgo]

In response to nanook and cub driver: I too used Gar Aeros for 10 years or more. I flew them throughout Alaska. I had the ground down 3 or 4 ply. I hunted with a guy who had AirStreaks and was always amazed at the streak's absorbtion. Gar Aeros are harder than streaks and harder than bushwheels. I finally bought 31 inch Bushwheel radials. I would not go back. When absorbtion counts, and it counts on the mildly rough stuff not just the real hairy stuff you should not be on in the first place, it counts big. Even the small rocks or driftwood can throw you, especially if there is wind, if you bounce over it with a hard tire on landing. A cub bouncing on a beach, gravel bar or hill can lead to misery. You can lower the pressure in the Gar Aeros, but then you' re taking on a new set of risks in landing and looking a longer takeoff roll, and from my experience, you still do not have the absorbtion of a streak or bushwheel. For what it is, and what it costs, the Gar Aero certainly has its niche. But it is not a streak or bushwheel in the absorbtion catagory. At least that has been my experience.

[cubdriver]

In response to nanook and cub driver: I too used Gar Aeros for 10 years or more. I flew them throughout Alaska. I had the ground down 3 or 4 ply. I hunted with a guy who had AirStreaks and was always amazed at the streak's absorbtion. Gar Aeros are harder than streaks and harder than bushwheels. I finally bought 31 inch Bushwheel radials. I would not go back. When absorbtion counts, and it counts on the mildly rough stuff not just the real hairy stuff you should not be on in the first place, it counts big. Even the small rocks or driftwood can throw you, especially if there is wind, if you bounce over it with a hard tire on landing. A cub bouncing on a beach, gravel bar or hill can lead to misery. You can lower the pressure in the Gar Aeros, but then you' re taking on a new set of risks in landing and looking a longer takeoff roll, and from my experience, you still do not have the absorbtion of a streak or bushwheel. For what it is, and what it costs, the Gar Aero certainly has its niche. But it is not a streak or bushwheel in the absorbtion catagory. At least that has been my experience.

I agree, but you just can't beat them for the price. If you regularly operate on the ragged edge rolling over volley ball sized rocks, the GAR's aren't going to do it for you. 99.9% of the places most of us go, they are adequate. I have noticed that my bungees only last 2 or 3 years, probably because of overstretching them.

The deciding factor for me, was some rides in Cubs with Airstreaks. Every landing was harrowing because of the extreme bouncing. Landings were best described as semi-controlled crashes. For a couple of seconds, the planes were literally, out of control. That just doesn't happen with the GAR's. I hope the Bush Wheel tires are better.

[Crash]

I hunted this year with a friend that has a PA-18 on 31" Bias Ply Bushwheels. My PA-14 is on 31" Radial Bushwheels. We noticed when we were refueling the planes at a bush village that the radials sit up higher then the bias plys. An even bigger difference though was how hard they were to push around on the ground, both on pavement and the sand bar where we were camped. Aftrer a while we started calling his PA-18 the lead sled. We had to really put our backs into pushjing his 18 around where as my PA-14 was at least twice as easy to push. I originally had the 14 on a set of 29" Bias Ply Bushwheels. They have a flatter foot print and profile. When I went to the 31" radials I picked up about 3 mph, I think it's because they come to more of a point in their profile and cut the air better. I am now fully convinced, the 31" radials are the only way to go!!! Crash

[Big AK]

I'm still on 30" Airstreaks, but have observed what Crash says as absolutely true.

I've also noticed that even the bia-ply 29" Bushwheels appear taller than my 30"streaks when they're on the a/c and side by side, close in pressure and a/c weight.

A couple of reasons the Radial 31's are awesome is that they have less rolling resistance, as Crash said, but also that they have a relatively narrow looking profile in flight, but when on the ground the contact patch is actually spread out, appearing as though the bottom of the tire has melted out to a "puddle" on the ground.

Saving my pennies......

DMC