D.A.'s new 105 Special

I wouldn't have gone looking for a 105 Special - - - but this one found me and I'm super happy with it, I think it's going to make a great "Old Man's" Cub. It's somewhat stock, including the O-235, so I'm down on power. I'm wanting to put big(er) tires on it and I'm wondering all your thoughts.

But before you chime in, let me tell you a quick story. When I was a kid (90 years ago) my friends and I had access to a 65 horse Champ that we abused as often as we could. 65 horse, 8:50's and a wooden prop, it taught you to manage your situation. Well, there was a sandbar that we'd go into all the time. It was always hard packed sand and the Champ had no problem going in or out on those 8:50's, even with a 65. One day I decided to go into the same sandbar with a 7ECA Citabria on 6" tires. You can see where this is going. Lets just say that on that day I would have given ANYTHING for EITHER bigger tires or more horse power. Either one would have made my life easier. The Champ with less horsepower AND less weight floated in and out on those 8:50's.

So now here we are with the 105 Special. What do you think, should I absolutely go with bigger tires because I'm down on horsepower or should I absolutely not go with bigger tires because I'm down on horsepower? What say you?

Also, catch me around the campfire some day and I'll tell you about how the U-bolts on the Citabria gear break....

Thanks in advance
D.A.

If you are going to do some of that soft ground; bigger tires and a relatively flat prop to get all you can out of it. You aren't going anywhere very fast anyway.

Bigger footprint for soft ground but not too large a diameter for the low horsepower. Too large a diameter can put you on the wrong side of the power curve when you have a load.

I had 31" tires on my 105 Special, but I think either 8:50's or 26" will be the sweet spot for you. One of the problems with that airplane is that it has a 1500# GW, so loading it up with a lot of fun gear and not doing the 1750# mod makes it hard to do a W&B.

sl

D.A. said:

Also, catch me around the campfire some day and I'll tell you about how the U-bolts on the Citabria gear break....

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No need to tell me, I had the gear fold on a Scout many years ago. Land, taxi back, almost stopped, and down went the wing.

I went from 8.50 to 26 ABW on my FX-3. 26 ABW much better than 8.50 for the places I take it and I don't need the cost, weight, or drag, of anything bigger.

Goodyear 26. CDA has a lot of asphalt and you will quickly wear out bush wheels.

If you can get them field approved, the Desser 27.5 wpuld be a great option. They last really well on pavement, and they're a LOT softer than 26" Goodyears. The only downside is they require a 8" wheel...

D.A. said:

should I absolutely go with bigger tires because I'm down on horsepower or should I absolutely not go with bigger tires because I'm down on horsepower? What say you?

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Probably the only one with this opinion but I say NOT go to the big rubber. Flying is what an airplane does, landing is incidental. Unavoidable yes, but still not the announced intent of the equipment. I say compromising the primary activity in favor of something only there because it's required just seems a bit odd to me - although many many people do it. Nothing wrong with it either if that's your deal, but you did solicit opinion.

If big tires are just calling your name, how about 8.00 X 6? I used to run them on a Cessna 140 as a compromise measure. Worked pretty well too. Improved off airport performance, but not big wheel performance. Cruise performance was not noticeably affected and weight and balance not at all. Not to mention they're (relatively) price friendly.

Just my opinion and worth every penny you paid for it....

Congrats on the new ride. I am envious. And still looking...

RedOwlAirfield said:

Probably the only one with this opinion but I say NOT go to the big rubber. Flying is what an airplane does, landing is incidental. Unavoidable yes, but still not the announced intent of the equipment. I say compromising the primary activity in favor of something only there because it's required just seems a bit odd to me - although many many people do it. Nothing wrong with it either if that's your deal, but you did solicit opinion.

If big tires are just calling your name, how about 8.00 X 6? I used to run them on a Cessna 140 as a compromise measure. Worked pretty well too. Improved off airport performance, but not big wheel performance. Cruise performance was not noticeably affected and weight and balance not at all. Not to mention they're (relatively) price friendly.

Just my opinion and worth every penny you paid for it....

Congrats on the new ride. I am envious. And still looking...

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I see where RedOwl is coming from, but i'd say get at least an 8.50, if not bigger. I know that the old timers went lots of places with small tires, but planes weren't nearly as expensive back then. The wear and tear that big tires save on your airframe is well worth the cost and added weight. In my opinion, if you're doing any off airport work at all, go with a bigger tire. Several options available, they all have their pros and cons.

Dresser Tires "Aero Classic" 8:50 ( pillow soft) tire would do about anything your likely to ever need to do. Less than
half the weight of a 26" Goodyear ( Blimp) tire; that are about "rock hard" when fully inflated......
The Aero Classic's are very soft; extremely lite. They give you about same AOA as the old 25x11x4 "tundra tires" that were the standard in Alaska for years. If you absolutely have to have the extra height???? Then 26" Airstreaks ( low pressure) ultra soft is next step up the ladder. But ALOT of folks would be shocked where a lite Cub will go; on a set of "Aero Classic's " tires.
Enhanced view from Mam's below

E

Desser Aero Classic 8:50’s.

Here's a pic to compare the Desser Aero Classic 27.5 to the 8.50

SJ said:

I had 31" tires on my 105 Special...the problems with that airplane is that it has a 1500# GW...

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Yeah, I've already resigned myself to the fact that it's a really cool single place airplane.

Bill Rusk said:

Goodyear 26. CDA has a lot of asphalt and you will quickly wear out bush wheels.

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You're spot on Bill. I had thought about running 26" GY's most of the time but having a set of 31's for running around the Palouse or into the hills.

1934A said:

If you can get them field approved, the Desser 27.5 wpuld be a great option....

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I'll look into those. Do you know any N numbers that have been field approved already? Does Desser have an 8" wheel available or do you just go to an 8" Cleveland?

I don't have any info as far as field approvals, just that someone a friend of a cousin's buddy supposedly has a FA...
Grove has a really nice 8" rim to run them tubeless. I have the weight of the tubeless setup somewhere. If anyone's interested, i'm sure i could find it.