Does anyone have any real world experience on the 29's vs the 31's? How big of a difference is there?

If it matters, going on an 1150lb Pacer.

Thanks

I've flown with 29 Airstreaks for a couple of years before I switched over to 31's. I really enjoyed flying with the 31's, I thought it handled side loads better. Bigger the tires the more brake you'll need, and I wouldn't about any loss in speed between 29 vs 31's. Mike

I should clarify, I have a considerable number of hours flying on 31" ABW. Just trying to see if the 29's are a trade down or if would be a negligible difference.

I had 29 inch on my pacer and loved them. You will get a better AOA with the 31 inch. If I was real slow I would land tail first with the 29 inch wheels so 31 inch would help that. I would order extra rubber with either one. How long are the strips you are working? Tire pressure is key to the bushwheel tire. Size of wallet is key in buying parts.
DENNY

Somewhat related: I found quite a bit of difference, all good, when I went from 26" Airstreaks to 29"'s. Do the math, (I didn't) but a 31" tire versus a 29" tire contains a LOT more cushioning air, more then may be apparent at first glance. My big fear is that ABW will come out with 31" Airstreaks (the lighter and less expensive Airstreaks are all I need and want to pack around with my LSA type bird, don't need the weight carrying capability of the "regular" ABW's) becasue then I will HAVE to buy a pair

Denny, I operate the Pacer out of our ranch and it's 1000' and not real smooth. Looking to get rid of the 26" Goodyears I just installed to mitigate some of the bumps.

I went from 26 in Goodyears to 29 inch Bushwheels, the difference was night and day. Everyone said my landing skills really improved, but the truth was the bushwheels more than made up for my lack of landing skill. I never tried the 31 inch but fellow pacer drivers up here loved them. If I had 29s that is what I would run, if I was buying a new set I would do the 31 inch mostly because I have the MOREBETTERDISEASE fever!!
DENNY

TJ,

The biggest difference between 29's and 31's will be flotation. If you are landing a lot of sand bars, have the 29's aired way down and still feel a lot of drag when you land, then 31's will improve that.

The second biggest difference is landing on bigger rocks. Again if the 29's are already aired way down and the rocks you are landing on can really be felt, 31's will improve that. Of course East Texas doesn't have any rocks, of any size, so most likely that isn't a concern.

Now as far as the "cool factor", well 31's beat 29's, and 35's beat 31's. But as the tire size increases the wallet size decreases.

See you at the Roundup!

Barnstormer wrote:TJ,

The biggest difference between 29's and 31's will be flotation. If you are landing a lot of sand bars, have the 29's aired way down and still feel a lot of drag when you land, then 31's will improve that.

The second biggest difference is landing on bigger rocks. Again if the 29's are already aired way down and the rocks you are landing on can really be felt, 31's will improve that. Of course East Texas doesn't have any rocks, of any size, so most likely that isn't a concern.

Now as far as the "cool factor", well 31's beat 29's, and 35's beat 31's. But as the tire size increases the wallet size decreases.

See you at the Roundup!

I would tend to agree with Phil about this, my thoughts exactly.

I traded up from 26 GYs to 31s, and I was not "wowed" by the difference in actual off airport performance. As was said above, it helps improve the landings because of the cushioning. In terms of gear noise and bumpiness landing off airport - I wouldn't say it was a really big difference, personally. There was a difference, but I think it was mostly in my head / wallet.

TxAgfisher wrote:If it matters, going on an 1150lb Pacer.
Thanks

It does... and depending on your idea of 'rough' it can be anywhere form negligible, to significant.

Having owned several copies of both, the oldest dating back to the pre Dunkin era, and the newest coming from Alaska again I am of the opinion that the single biggest difference between 29" and 31" ABW's has nothing to do with the rolling radius. It also has very little to do with contact patch size.

Land two similarly weighted airplanes on smooth sand, and the tire tracks will look identical. This suggests the contact patch is almost identical.

Then air each tire up to appropriate pressures for the mission and A/C weight and you will find that the actual rolling radius (measure the axle height off the ground, not the circumference of the tire) is almost identical.

The reason for the closeness in rolling radius is where the biggest difference in these tires lies. It's the sidewall.

The sidewall of the 29" ABW is substantially stiffer than the sidewall of a 31. This difference makes the 29 stand more erect than a 31 at the same air pressures under the same A/C. On a lighter airframe, this translates to a stiffer ride. On a more appropriate weighted airframe for the 29 ABW (such as a C180) the stiffer sidewall may actually favor your flying style / mission. Anyone who has gone from 26" goodyears to any flavor of appropriately aired bushwheel should understand this concept. Mind you, very few people I have witnessed flying ABW's run them at optimal pressures for the conditions. Most shove them out of a paved airstrip hangar, and then head to the beach or boulder pile. I am frequently guilty (but cognizant) of this.

Last but not least, people frequently use the term 29" bushwheel to describe actual 29" Alaskan Bushwheels, as well as
29" Airstreaks , made by Alaskan Bushwheel. The difference between these two is significant, and again, selecting the appropriate one to your mission / A/C weight / flying style, is going to be critical to maximize your smiles per dollar.

These tires represent a substantial expense. I have purchase less than optimal sizes in the past, but only when they come at a smoking deal (used) or when I could put them on another A/C if I was unhappy with the A/C I initially purchased them for.

Bottom line; Unless you're getting the 29's at a smoking deal, I'd probably pass until you find a deal on 31's.

Take care, Rob

The sidewall of the 29" ABW is substantially stiffer than the sidewall of a 31. This difference makes the 29 stand more erect than a 31 at the same air pressures under the same A/C. On a lighter airframe, this translates to a stiffer ride. On a more appropriate weighted airframe for the 29 ABW (such as a C180) the stiffer sidewall may actually favor your flying style / mission. Anyone who has gone from 26" goodyears to any flavor of appropriately aired bushwheel should understand this concept. Mind you, very few people I have witnessed flying ABW's run them at optimal pressures for the conditions. Most shove them out of a paved airstrip hangar, and then head to the beach or boulder pile. I am frequently guilty (but cognizant) of this.

Rob's description is spot on! I flew both the 29s and 31s on my Supercub and I am convinced that the 31s are the perfect tire for the flying that I do in that plane. The sidewalls on the 29 are stiffer and probably great on a heavier plane (like a C185), but I found them to be too stiff for an 1100 to 1200 pound plane landing on rocks and bumps. I know nothing about Pacers, but assume that the softer sidewalls of the 31 would be beneficial.

Chris

Thanks Rob, that is exactly what I was looking for. I'm only getting 110mph now, with ABW I'll be as slow as the cub guys.

The airplane actually had 31's on it when I bought it but I didn't fly it with them because I knew I wouldn't give the 26" GY a chance.

I think the sidewalls are both made the same. Tire pressure and ground distance from the wheel are most likely what make them feel softer.
DENNY