Looking to see what size I should get for my 185, I have a spare set of 31s but I just realized they’re not approved.

I have 8.50s on now and don’t mind switching back and forth for summer and winter. Mainly stick to gravel bars, sandbars, and soft fields, nothing at gross weight.

I’ve only run 31s on my cub and 170 so I don’t know if there’s any real difference between a 29 and 26 for the above use.

I flew a 185F for a state forest service for 7 years. It had 8.00x6 tires, which are too small in my opinion. If I had owned it, I would have put Alaskan Bushwheels 29" tundra tires on it with the heavy duty tread. The heavy tread should last longer when landing on hard surfaces. I've had 31" ABI Bushwheels on my Maule MX-7-180 since 2016 and there's no cord showing. I operate mostly on grass but occasionally land on hard surfaces. I've heard that heavy bushwheels can vibrate at certain airspeeds on a 180/185 due to the flexibility of the spring steel main gear legs but I don't know if that's true of the 29" tires. My Maule has oleo struts which don't vibrate at any speed. McFarlane has an STC for the 29's that includes the 185.

I like 29's on my 180 but haven't tried 26's. I've used Herculiner to build tread back up and that works but make sure it is even so not out of balance.

I don’t have any 185 experience, but flying in Alaska I’ve never wished I had smaller tires.

Small thread drift, but on topic.

I noticed this rough patch on my 29”. Any ideas?

You can still get that gear leg wobble on a 180/185 with 8:50’s. I would get it occasionally in mine.

I run 31's under our 180H (3190 up-gross) and they greatly smooth out the ride on our most frequented rough strip, saves wear on the airframe (exactly as they were designed). For a late model 185 I would opt for the 29's. I apply brake after safely airborne to stop the rotation on both the Cub and 180, thus no issue with vibration/wobble as suggested.

TR

That spot is from sitting too long on probably contaminated concrete. Say hydraulic fluid (or some such) attacks the rubber. I make a habit of putting all tires on small entry way rugs, even in the hangar.

For what it’s worth, and you should double check with the mfr, but I believe that that insult is not a structural concern. I called a while back as a customer had the same thing, and was “told“ not to worry. Do your own homework.

RE: tires… best Wagon tire bar none is the 29” ABW. Of course there are always caveats. Expensive to run. They don’t last very long if you’re running on pavement. They slow you down. You have to really watch how you’re taxiing. They do vibrate at cruise, which imparts a lot of unexpected, and unanticipated forces into the fuselage over a long period of time. As suggested, heavy treads will help longevity, but they impart more forces. This is important, especially in an early model wagon, where they are not built as strongly as the later models. If an aircraft has suffered damage in the past, this can really exacerbate the weakened structure; I’m finding more and more popped gearbox rivets. Any kind of bedliner is obviously not approved for certified aircraft. 31 is (as mentioned) not approved for the A185F, but IMO, the juice isn’t worth a squeeze. They are too big. I usually set every airplane that I’m involved with up with the 8.5x6 Dessers. They are light, only 4 ply, and some have discussed anecdotal stories of tires getting damaged. But really work well as an all around gentleman’s tire. The issue is, they don’t make you feel cool, and they’re not approved on the 185 because of the load limit. There is a relatively new choice, which is going with a 29 inch Desser. It seems like it’s a pretty good compromise. Just as tall and wears very very well. Because nothing is perfect, they are not as pliable as the bush wheel, and you have to switch to the Grove 10” system. I have two sets on order for separate customers. I’ll know more by the end of the summer I’m guessing. In a perfect world, I love having the small Desser on one set of wheels, and the bush wheels on another. Swapping back-and-forth is easy. Going with the Grove removes this prospect. So in the end… one last choice, I believe that before he left, Geoff at sea Plains North got an STC to run the 26 inch Goodyears; I had no personal experience with this setup. I guess to answer your original question… With respect of 26s, I kind of feel like what’s the point? If you’re worried about any downside like speed or weight, run the 8.5 x 6. Everybody in the past did almost everything we do now with those tires and didn’t know any better, having just as much fun. If you wanna take it to the next level, feel cool, spend some superfluous cash, while protecting the air frame, all the while having a blast… 29’s. It’s a really complicated decision. There are no easy answers, and everything comes at a cost or price. And oh by the way, there’s about 15 years of discussion here on backcountry Pilot about this topic, lol. In the end, here’s how I look at it: I don’t know a guy that’s operating a wagon that isn’t $400-$500,000 at the end of the day. This sucks, but that’s another thread. So at the end of the day, a one percent expense that brings tons of joy for me, is an no-brainer. If I only get a season or two out of the set, then I just go buy another. That juice is worth the squeeze as the smile and the joy that landing with those tires brings is everything to me.

Thanks I bought a set of 29 with heavy tread. I already have a 10” tailwheel on so I’ll see how it works before trying to mess with the tail.

Is there an easy way to get these changed on the ramp? I use the gear leg jack on my 170, but this is a much heavier plane. Are the ski axles ok to use to lift on.

The damage to the tire is from where the tread layers join. If you look at the tire you can see its a little lower there, I have seen it on many tires. I fill it in with black silicone put on thick, a half dozen landings will smooth it off. Silicone will cover over thin spots for a while, keep reapplying and you can extend tire life quite some time.
These days I don't land on asphalt much at all, silicon can probably extend tire life for a year or more. The one tire that I had that same thing, had a line of pin holes leaking air one day all across the tread where the seam is. I rolled it for that side down and the slime or orange seal or whatever I had in the tire stopped the leaks long enough to get home 6 hours later and change the tire.

Dbl post

31s baby!! overcompensate!!

Another option mentioned earlier is ten inch wheels and tires. That gives you the option of either 8.50 x 10 tires (about 26 inch diameter) or 31 x 29 x 10 tires, which come out to about 30 inches. These are NOT tubeless tires, so you can't run them at the super low pressures that Bushwheels permit, but these wear a LOT better on pavement. And, where floatation is required, as opposed to "give", these work fine.

Airframes Alaska, now McFarlane Alaska, sells the ten inch wheels with STC for both size tires.

I have a 185 that had 8.00s and switched them out for 26s. The 8.00s were faster but only about 4 knots. On rough strips the fuselage would take some abuse from the hard small tires transferring a lot of the bumps to the airframe. I have the HD Bushwheels. My cruise is 147kts ROP and 136kts LOP with the 26s. I thought it was a good mix of speed and backcountry use. I have 29s on my SuperSTOL and think they are pretty close for feel on landing rough areas. For reference mine is a 1982 185 with an IO-550 and wingX tips. I've seen a few 185s in the shop with a lot of play and/or damage in the gear from the heavy goodyears and big bushwheels. Not sure if it's the weight and leverage on the gear leg or just bad landings.

mtv wrote: Another option mentioned earlier is ten inch wheels and tires. That gives you the option of either 8.50 x 10 tires (about 26 inch diameter) or 31 x 29 x 10 tires, which come out to about 30 inches. .....

Several people I know run the 29x10 airhawks, shaved or not.
But I'm not familiar with 31x29x10 tires--
maybe you're referring to 29x11-10 ?

hotrod180 wrote:

mtv wrote: Another option mentioned earlier is ten inch wheels and tires. That gives you the option of either 8.50 x 10 tires (about 26 inch diameter) or 31 x 29 x 10 tires, which come out to about 30 inches. .....

Several people I know run the 29x10 airhawks, shaved or not.
But I'm not familiar with 31x29x10 tires--
maybe you're referring to 29x11-10 ?

My bad, they're 29 x 11 x 10 tires. Sorry.

I assumed the OP's inquiry was limited to ABW's, however, since it was brought up, here is a shot of a GoodYear 29 alongside a GoodYear 8.50 for comparison. I would not recommend the 29 on a 180/185 as they are heavy and stiff (as previously stated, I run ABW 31's on our 180H). I only run 29's on the Beaver as a cost effective method to obtain additional prop clearance and larger footprint, however, even at Beaver weights, they are a stiff ride. On a positive note, they wear very well. If not for float and ski ops, I would be running ABW's on the Beav as well.

TR

Most folks I know who run the 29 x 11 x 10 have them buffed down to remove the tread. That removes a LOT of the weight, and makes them a lot more flexible. Buffed, they're not a bad option for a 180/185 that operates on pavement a fair bit.

Please define “a LOT of weight” and “a lot more flexible”. Decisions should be made with data and numbers vice non-definable terms like a “a lot”.

Without looking at my W/B data, (I swap the 29’s for 8.50’s on skis), I recall the GoodYear 29 at approx 36#. I have never altered any of my 29’s over the past decades thus have no idea what the weight savings could be by removing material from the tread.

Being of bias ply construction with a 10 ply rating, I have a hard time believing that removing material from the tread has much effect on sidewall flexibility or I should say lack there of with the relative light load of a 185. The 29 is better suited for the loads of Ag Aircraft, in this application it performs exactly as designed. The 180/185 lacks the loading to exploit the attributes of the 29. Much like putting load range E truck tires on a VW bug.

TR

I have never been a fan of 10" wheels, at least not on a180/185.

I mounted up a set of 29-11-10 a few years back, they were HEAVY. So, heavy that I put them on the scale, 63# for a tire and wheel. Shaved or not that's insane. Tires made for an 802 have no place on a 185.