Running 7.00-6 tires ?

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Gone Flyin

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Gone Flyin
My Cessna 150 uses 6.00-6 tires for the mains.

I'd like to go up one size to 7.00-6. About 1.25" larger diameter than the 6's. The other dimensions for rim and width are the same. A bit more weight capability for the 7's.

Thinking the extra size will provide more cushioning for landing on grass and gravel. Will also replace my rotors and pads in the process.

My IA is fine with it and says he sees them used all the time. I'm still wondering if this will come back to haunt me later. Do I need to do a 337 as a minor alternation or get way deeper?

Asked Cessna for comments but have not heard back as yet.

Any thoughts?
 
the tires are not listed on the TCDS. the parts manual will show approved tires as does the equipment list.by the way, for 70 -77 150 there is an option for whitewall tires. 7.00x6 tires are not approved for that aircraft. this leads to two methods to install them on the aircraft.
1. see if an STC is available for the modification. i have no idea if there is one.
2. a field approval from the fsdo and proper 337 paperwork. this process is not that hard, it just takes time. i just got one done for 'bigger tires on a c-140.

by the way, you never use a 337 for a minor modification, that is a log book entry only. a 337 is only used for a major alteration or repair.
 
Gone Flyin said:
Any thoughts?
Click to expand...
I dont recall any factory options to put 7.00s on a 150 but I believe there are a few STCs that provide it. Can also go the 337 field approval route since it is a major alteration as the tires are actually part of the landing gear system dynamics. But since your IA seems to support it, I'd ask him how he would do the paperwork and have him show you the reference. He might have something I havent seen or forgot about?
 
Gone Flyin said:
My Cessna 150 uses 6.00-6 tires for the mains.

I'd like to go up one size to 7.00-6. About 1.25" larger diameter than the 6's. The other dimensions for rim and width are the same. A bit more weight capability for the 7's.

Thinking the extra size will provide more cushioning for landing on grass and gravel. Will also replace my rotors and pads in the process.

My IA is fine with it and says he sees them used all the time. I'm still wondering if this will come back to haunt me later. Do I need to do a 337 as a minor alternation or get way deeper?

Asked Cessna for comments but have not heard back as yet.

Any thoughts?
Click to expand...
You can get a set of monster retreads from Dresser that are taller than stock 600. I am not sure how they measure up compared to 700? I really like them for rough terrain. The heavier, deeper tread takes the bumps better and run real smooth on pavement.
IMG_1965.JPG


IMG_1894.JPG


IMG_2284.JPG
 
Gary Ward said:
You can get a set of monster retreads from Dresser that are taller than stock 600. I am not sure how they measure up compared to 700? I really like them for rough terrain. The heavier, deeper tread takes the bumps better and run real smooth on pavement.
Click to expand...

Gary:

I assume you are talking about these, correct?

https://www.aircraftspruce.com/catalog/lgpages/retreadtires66.php

https://vansairforce.net/community/archive/index.php/t-125707.html

Seems there are several comments on the web on these tires having issues... coming apart, dry-rot, splits, needing to be balanced. Others say they love them... no issues.

Have you had any issues or know of those who have? How long have you been running them and on what kind of surface?

This is certainly a viable option and not have to deal with the FSDO. I will still search out an STC, though. Changing out the fork for larger was not something I wanted to do and the cost is way high.

Thanks

BTW: I removed my wheel pants a while back and just had my IA redo the weight and balance. Since this must also affect the dynamics of the landing gear... as was mentioned above... how is this allowed, then?
 
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Yes those are the ones.
I had been running them 11 months now with no trouble.
All grass/turf ops so far along with plenty of paved landings. Also winter ice and some snow this past winter.
I can assure you that Dresser would not sell a tire that was going to fall apart.
I know several other pilots who have used Dresser for tires for 30 years.
The retreads I received are nearly perfectly round and balanced, better that the Air Hawks I removed.

Mine are on a 172 and fit no problem under my wheel fairings.
They are on Goodyear flight II casings. They came with a yellow tag.
IMG_1541.JPG

My first 2500 landings were 90% on paved runways. Now I am at about 50% of my landings are on turf. I bet these tire never wear out, just time out. Always new tubes with new tires.
IMG_1542.JPG



This picture is from just a couple nights ago.
IMG_2841.JPG
 
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unsafervguy said:
the tires are not listed on the TCDS. the parts manual will show approved tires as does the equipment list.by the way, for 70 -77 150 there is an option for whitewall tires.
Click to expand...

It is now my goal to find either a 150 or any other bugsmasher out in the wild with whitewalls :D


As for the topic at hand, to each his own but do you really want to add any more drag to that underpowered airframe?
 
Why not just leave the main wheels/tires alone and put the Cessna heavy duty nose fork on this?

Or just leave it alone. The turf that 99% of people fly off of requires no special aircraft preparation.
 
A bud did get a Field Approval for 8:00 x 6 for the Mains on a 150F. He already

had the Cessna heavy duty 6:00 x 6 X 15 (?) Nose Gear.

Approval was based on Certification Basis . CAR 3 ? That reg states “tires must fit

the rim and be of appropriate load carrying ability” or similar.

Some FSDO’s have only certain folks approved for tire mods.

My guess is there is no distinction between the mod mentioned and full

bushwheels.

My personal choice is usually larger wheels per comments. However; the

Nose Wheel should also be considered. When touching done on soft surfaces

the little one in front tries to dig in. This imitation of a plow can then lift the

Mains off the ground. Since 150 Nose Gears are not designed for this the Mount

then breaks. The result is a Prop Strike, firewall damage and probably a

Wing Tip Strike. There are limits.


One reason for specifying tire is effectiveness of braking.

A larger tire exerts more leverage on the stock disc. Barely noticeable for the

proposed change but is more apparent with size increase.

“ Steve’s Brake Booster” and other units must be used on some aircraft in

order to raise applied brake pressure and retain sufficient braking.

Most common on fabric Pipers.


Note that many Insurance Co. take a dim view of unauthorized modifications.,

Usually found post- incident. Keep it in mind when documenting change.


Airworthiness = complies with the Type Certificate &

in condition for safe flight



EVERY Insurance Application Application I’ve seen asks;

“ Valid Airworthiness Certificate?” They are not asking if you have the Cert

but rather do you comply with what it says. Just saying!
 
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I believe with the Dessers you can request the casing you’d like. That might make a difference in the “feel” of the tire.
 
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Gary Ward said:
Yes those are the ones. I had been running them 11 months now with no trouble. All grass/turf ops so far....
Click to expand...

Many thanks for the additional information and the photos. I envy you that fantastic grass location in the last photo.

I think the Desser Monster Retreads are the best option. Slightly larger diameter with deeper tread but they are also a 4-ply, are they not.
Going from 6 down (back to really) 4 should also mean a bit softer landing from the get-go. I believe the OEM tire on this plane was a 4-ply.

Can I ask what tire pressure you run them at and what does your 172 call for, if that is something different?
 
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duplicate post
 
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Found this from reading my Cessna 150M POH:

It calls for:

WHEEL, BRAKE £ TIRE ASSY, 6.00-6 MAIN
TIRE, V-PLY BLACKWALL (EACH) Part # C262003-0101

I assumed the V-PLY is a misprint so researching the part # online I get this:

TEXTRON AVIATION PART NUMBER
C262003-0101
TIRE 6X6-4

Therefore, the OEM tire is/was a 6.00-6 4-ply.

There is quite a bit of discussion on this forum from years ago about 4 vs 6 ply.

https://www.pilotsofamerica.com/community/threads/tire-thickness-4-ply-vs-6-ply.109723/

Things like side load on the axels and shock absorption for the Cessna landing struts.

Seems to me the 4-ply would be a bit more forgiving on landing all the way around (less stiffness and less weight) and, since it was called for in the design, should not be a negative.
 
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Magman said:
...My personal choice is usually larger wheels per comments.... One reason for specifying tire is effectiveness of braking. A larger tire exerts more leverage on the stock disc. Barely noticeable for the proposed change but is more apparent with size increase....
Click to expand...

Can I assume going with 4-ply VS 6-ply (1150lbs per tire VS 1750lb) I will aid the braking a bit with the softer (read flatter) tire?


Note that many Insurance Co. take a dim view of unauthorized modifications...Usually found post- incident. Keep it in mind when documenting change.
Click to expand...


Would going with the 6.00-6 Desser Monster Retreads be considered a "modification" or just "new tires" in the log book entry?

Thanks!
 
Hopefully the difference is not needed on a 150.Bigger tires = bigger diff though.

My thought is the Monster is not an issue on fixed - gear no fairings.

Fairings or jamming on retracts can be a problem.

Some tires sizes have a different profile that can result in rubbing the caliper.

I believe the Monsters are not a problem as it is added material to tread only.

Not an Alteration.


Running tires to “ first cord showing” is not wise.

Put fingers in and out and you may be surprised how thin it is.
 
The monster retread I am using is on a casing that says 4 ply on it. That is what you should run on a 150 and a 172(160hp). My mechanic signed off as new tires.

Are they still 4 ply with 11/16" tread glued on to them? I don't know?
I do know that my old thin wore out tire weighed 8 pounds each with tubes and the new tires without a tube weighed 16 pounds each. I was alarmed at first being I was losing at least 16# useful load. It is what it is and I am glad I went with them.
As far as smooth landings, isn't that up to the pilot?
IMG_1543.JPG
 
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Gary:

Well, I removed all three of my wheel pants two years ago and never looked back. So... the weight savings there should make it more or less a wash with the new tires.

I ordered the same as you, the 4-ply (on Goodyear Flight Special II) as it was specified by Cessna for this plane. I did have 6-ply Condors on since I took delivery of it three years ago.

BTY: If you order from Desser direct the price is better than the dealers and free freight.
 
When you get them how will you balance?
 
Assuming you have assembled line on tube with mark on tire?

Temporarily install wheel assy on axle with dry bearings and see it it consistently drops a heavy side.

or

Some RV/ motorcycle shops have the capability.

Use stick - on weights.


I have a “ wheel - spinner” but no way index.

Grind off brake disc ridge while it’s convenient.
 
I have a McFarland static wheel balancer. My retreads didn’t need any weight added.
Be sure to place the red dot at the valve stem as it is the lighter side of the tire. Except if there is a yellow dot…
 
Gary Ward said:
I have a McFarland static wheel balancer. My retreads didn’t need any weight added.
Be sure to place the red dot at the valve stem as it is the lighter side of the tire. Except if there is a yellow dot…
Click to expand...

Gary:

Can you tell me what pressure you run yours at. Is it what the POH calls for or something else?

Thanks
 
Pretty sure just going to a 4 ply from a 6 ply is going give you smoother landings I think for a 150?
 
Gary Ward said:
Pretty sure just going to a 4 ply from a 6 ply is going give you smoother landings I think for a 150?
Click to expand...

I'm looking forward to trying them out.

I need new tires and rotors anyway and want to do more grass strip landings so I'm glad you made the suggestion to go with the Monster Retreads.

BTW: I contacted Cessna, on advice from a flying friend, but got nowhere. The senior engineer would not comment on running larger tires... not even on 6-ply over the OEM 4-ply. The Monster Retreads were aftermarket so that was not up for discussion either, he stated.

Well, I tried.
 
First thing I noticed on take off is my tires zinged up in rpm from the additional weigh on the outside of the tire.
Got used to tapping the brakes after lift off.
 
How would you like to make any product and then have folks later modify it?

Some of these people may have zero credentials or experience too.

Oh; by the way , your name and liability is still in existence.


The Field Approval and STC Systems are imperfect but address this situation.

People that develop an STC for these mods are often stiffed on the selling price

by those referencing the STC but not buying it. Hence the “ Permission Letters”

in common use today. ie Buying a used Garmin radio does not automatically

entitle you to use their STC.
 
Bell206 said:
Curious. What comments were you expecting to get from tech support?
Click to expand...

I was hoping there had been some work done since 1976 that might address using different size tires.

In fact, they was. There was/is the update to using a heavier duty nose wheel strut and that would allow the use of larger mains tires. Cost in the thousands.

I only wanted to know if I could use 7.00-6 mains with the OEM nose wheel and strut. They have never tested that, apparently.

Simply felt it was better to have the blessings of the manufacturer, if I could get it. Should I get ramped checked, I'd have them to back me up.

In the end, I will go with the 6.00-6, 4-ply Monster Retreads. Safer alternative and will still do what I want.

Does that answer your question?
 
Gone Flyin said:
Does that answer your question?
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Yes. Some people have a misconception of what OEM tech support is there for and sometimes wont get the full benefit of their services. Have known a number of people who got quite upset when they didnt get the OEM "blessings" for a particular inquiry. But it seems you received the info you needed and went with a good plan.
 
Even the OEM cannot bless things that are in violation of the TC. Even they would have to either modify the TC or get an STC approved.
 
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