I'm working on a field approval to put 8.00x6 on my Luscombe. I got a couple copies of 337's from when a couple other guys put 8.00 on their Luscombe's. I guess my question is will it be worth it? I don't know how much bigger the 8.00's are than the 6.00's When I landed at Copper Basin and I felt like my teeth were going to rattle out of my head. It was even worse when I landed in the Idaho dessert by the Big Southern Butte. I just want to provide as much cushion to my airframe as possible, it is almost 60 years old.

Thanks, Jon

Oh yeah, the guy that owns the M-4 I was lookin at decided to fix it up then sell it. I'm just going to stick with what I got for a while.

Just go a head and put 8.50's on and run them at about 10-12 psi for the off airport stuff. I took my Tcraft all over the place with 8.50 and they were just about right for 75% of the stuff. Of course they were nothing compared to the AK bushwheels that I was lucky enough to use for a season. All that effort for such a small increase in tire size would be disappointing. I would be watching that tail area I have just rebuilt the complete tail end of a luscombe and they are not designed to take much abuse. Give Brandon at the Luscombe foundation a call and ask him about the "loose" rear ends they see coming through their shop. There are a few updates that I would consider doing if I knew I was going to be spending a lot of time operating from unimproved areas. Keep a close eye out for smoking rivets!

Jason
N3673T

jgerard wrote:Just go a head and put 8.50's on and run them at about 10-12 psi for the off airport stuff. ...Jason N3673T

What's the optimum p.s.i. that I should use on my 8.50's for a combination of landings on either pavement, gravel, or turf? -Can't be switching the pressure all the time. Currently, I'm using about 18 p.s.i. - but I just filled 'em 'till they looked & felt right, and that's what the gauge reads. Is that too much? I guess it also depends how heavy / light I'm running, too.
Thanks for the suggestions, Berk

depends on how heavy your plane and how effective your brakes are.

Light stuff like J-3's, Tcraft, Luscombe, and Champ - (mostly under 1500lbs gross) can safely operate at 10 psi and not worry about spinning the tire on the rim and ripping the valve stem out. When you get up to the 2000-2400 lbs airplanes you will need about 16+ psi to handle those loads and stronger brakes. The 26" good year tires do not seem to have enough flex in the side-wall to be worth while on the light planes unless you needed the slightly bigger foot print for soft ground. I have been on 4-5" rock in my old Tcraft with 8.50's. WAY to bumpy for repeated use, but it can be done. I tried pushing the plane by hand over to the smaller rock for takeoff but could not move it at all. Had to fire it up and taxi it over. Old bushpilot rule is to figure 25-30% of the side-wall height is a safe size of rock to operate from.

http://gallery.taylorcraft.org/main.php?g2_itemId=2498

Jason
N3673T

In my opinion the difference between 6.00 and 8.00 tires is sizable, as is the difference between 8.00 and 8.50 tires.

My plane already has the STC for the 8.50 tires, but I am thinking of putting 8.00's on there (which are on the original type certificate for the 170) instead as I will be landing on pavement often for my trips to town, plus less drag for the cross countries. Right now I am running 7.00's which work well on pavement and grass but can be a little bumpy when the strip hasn't been rolled or mowed in a while. I hope the 8.00 remains a happy medium between rough strips and Fairbanks Int'l

At work we have a Husky and a 185 both on 8.00's and we do light off-airport stuff all the time, though I will admit our gravel in the interior is smaller than the rocks shown in the photo linked above.

Another issue is, I have single puck clevelands and in a 2200 lb airplane with 8.50's I think I would want double puck, which is another expense.

Here's a photo of a Luscombe on what I believe are 8.00 tires. The perspective is off a bit but I don't think they are big enough to be 8.50's - I could be wrong.

http://www.downtoearthphoto.com/pix/luscombe.jpg

Having just put brand new single caliper Clevelands on with 8.00x6 tires, I can say the braking is outstanding. Of course, my testing has only been lightly loaded, but I don't think you'd need the double pucks on a 170 if you're operating at or under max gross.

The 8.00 is pretty much the same diameter as a the 7.00, but it has a wider footprint. 8.50's are considerable larger dia, and if I really thought I was going to land on some rough stuff and be able to get back out with this engine, I would probably go that route. On the 170 I think you need a field approval, and I've heard 8.50's flutter the stock 170 gear (hence the need for 180 gear!)

That's my experience, having thought a lot about it as well.

Once and Futr--Take another look at those tires on the 185 and Husky. Last I saw of those airplanes, the 185 only lived on 8.00's during winter, when on wheel skis. The only DOI Husky I ever saw on 8.00's was the one I operated for a while looking for max range.

I'd be really hesitant to operate a 185 "off airport" on 8.00's.

If you run any tires at a lower psi than recommended by the manufacturer, be sure to put some slippage marks on the tires and rims.

Just paint a line, on a radial across the wheel/tire interface.

Now, a pertinent part of any preflight or post flight, for that matter, is inspecting the tire/wheel slip mark to verify that the tire isn't starting to rotate.

If the tire slips, it'll take the tube with it, and will shear the valve stem, which is threaded through the wheel.

As previously noted, tire pressure should be directly related to aircraft weight.

Also, when temps start to drop, WATCH THOSE PRESSURES. If you are operating at 12 psi on 8.50's, keep the airplane in a warm hangar, and verify that the tires are at 12 psi inside, it is important to understand that rolling that aircraft outside, and letting the tires cool will result in a significantly lower pressure in those tires.

So, next time you come home, check the tire pressure outdoors, when the tires are cold. Inflate them to the desired pressure cold, and they'll exhibit higher pressure when parked inside their warm hangar, which is okay.

Check pressures seasonally, as well, for the same reason.

The ABW's get away with operating at very low pressures because they are tubeless tires--slippage isn't an issue.

MTV

Just a question, 25 years ago when I put single puck Cleveland wheels and brakes on a 1955 C170B that I owned the installation instructions were very specific that they were approved only with 6.00-6 or 7.00-6 tires. Even though the type certificate data sheet approved 8.00 tires, they were only approved on the orginal Goodyear wheels and brakes. Now my question, is this still the case, or are the 8.00's now approved with the Cleveland wheels and brakes? Thanks, Tim

jgerard wrote:.....................
Jason
N3673T

Looks like you got yourself another T-craft, eh Jason? Are you back up here in God's country again?

Eric

You can drill out the hubcap holes and run screws on through the wheel rim into the tyre bead to stop slippage. Hard braking will spin 8.50 tyres on 2300lb aircraft at 18lbs. otherwise.

The double-puck Cleveland STC for the 180/185/206 (# SA63GL) has a few restrictions:
1) only use Cessna axle p/n 0541124 & 1441003-1.
2) not approved for use with crosswind landing gear
3) approved only with 800 X 6 tires.
The double-pucks on my 170 were field-approved on a 337 which referenced this STC. However, the 337 clearly states that 700 X 6 tires were installed. Go figure, eh?

Eric

I went to the 8.50 this year on my stinson, there is an stc for the installation. I love the way they work off field.

I removed the wheel pants and installed the larger tire. I only noticed a very small loss of cruse, in fact it was barly measurable.

Looks like you got yourself another T-craft, eh Jason? Are you back up here in God's country again?

Yup, I picked up N3673T. It is a 1975 F19 0-200 1500lb gross. This is the one that Taylorcraft used allot for advertising. I bought it unrestored or modified in original condition with 1280 TT and 100 stoh. It WAS full IFR but I managed to pull all that junk out -78lbs. Now its just like my old BC12D but with more hp and about 10 times the baggage area. I've been across the country many times in a non electric equipped airplanes and never had a problem. Heck I aint smart enough to use all them fancy gadgets anyway or dumb enough to fly in the clouds expecting them not to fail. I would rather be looking out the window with my finger on the map. Also I have yet to see any published approaches for my favorite gravel bars! Mark Huntwork AKA "Beagle" bought my old Tcraft N43643 and he is re-assembling it in Oregon.

I might be retuning to the NW in the spring. Not sure if I can take another Texas summer. I sure miss the mountains and my webbed feet are just about dried out!

Jason
N3673T

Higgy, do you have any pictures of your -3 on the 8.50s?

No, I will go and take some this week and post them for you.

It looks great and the plane handles well with them on the ground.

Dane

Can anyone scan & e-mail me a copy of their Cleveland (Parker
Hannifin) STC SA63GL (Install Cleveland wheel and brake
conversion kit, P/N 199-62)?

I'm interested in the Kenmore 8.50x6.00 tire STC for my '54 C-180
and that STC (SA361NW) says the wheel/brake installation needs to
be per Cleveland STC SA63GL, but the FAA web site (as well as
Parker's) doesn't have any detail as to what SA63GL specifies.

TIA,

I am doing the resurch on this one now, you will need the 6 bolt wheel for that STC so you need the 199-62A kit. so add another $300 or better to price tag.

Unless the requirement has changed in the last 2 years, this Stc calls for either 3 bolt or 6 bolt wheels (D or T) on the installation drawing. Both call for the deep disc dual puck brakes. I will verify this when I get home Wed. and correct if I am in error. This is based on 2 years ago, also at that time the Kenmore 8.50 stc could be used with both McCauley or Cleveland wheels.
Tim

Tim that would be great as I don't want to sell the guy something he don't need!!!