I recently disposed of the wheel pants on my plane and installed the larger tires described above after removing the factory 11-4X5’s. I gotta admit that the difference is more than I expected. The plane feels so much better during the take-off and especially the landing roll out. It simply feels much more attached to the pavement and seems to be more controllable with much better behavior.
Maybe it’s just my imagination but, to me the change is quite noticeable and welcomed. My initial test pressure has been 30-32 PSI and thus far that has worked well. Obviously these tires have a larger contact patch and perhaps that is what is making them feel like they stick to the surface much better.
But they seem to roll easier and steering (whether with rudder or tail wheel) feels more confident.
Or maybe I’ve finally learned to land this thing! Nah, can’t be that …
I preached against the big, heavy tires before but after we have flown to a lot of grass trips I’m trying to lose weight to justify the extra mass of the larger tires. On some of the strips we have been to it is like the brakes are on - high power required to taxi. Takes a really long time to get up to flying speed.
I’m guessing that with the removal of the wheel pants the weight difference is not much especially after all the fiberglass and metal I added to the old pants because of cracking when flying from grass fields.
I might lose a bit of speed without the pants but I retained the leg fairings. I haven’t performed any real testing to determine speed loss but it doesn’t seem to be much if any at all.
So far I believe the trade off is worth it (except the cost of the new tires and tubes - OUCH!)
I have the 4ply Air Trac in the same size on my Onex. I had them from the start because I needed the prop clearance. I modified the wheel pants to fit, but I really needed larger wheel pants. Eventually I took them off completely because it just wasn’t worth the hassle having them in the way of checking pressure and inspecting the brakes. Oddly, the plane looks better without them, and I only measured 3-4 mph difference. I don’t go anywhere, so I don’t miss the wheel pants at all.
I flew my Onex from the beginning with with a gear leg 3” extension, 5.00x5 tires, Matco
wheel-brake-axle set, toe brakes and 6” castering Tailwheel. Landed on grass for the first time yesterday - seemed fine, east to taxi and maneuver.
I initially flew without wheelpants, then made plugs and molds to produce carbon fiber pants very similar to the Vans style pressure recovery pants. Installing the pants gave a solid 7 kt improvement in speed. Corvair 2850 engine with Sensenich 54x58 prop. I have a 60x52 prop on order, looking for better take-off/climb performance.
Early on, most of us began flying with the 5x5 tires but eventually switched to the smaller tires seeing little advantage to carrying around 3 1/2 # more weight. Even Tony Spicer, who flew off of a grass runway, switched to the smaller tires. The fellows who operated off of grass runways frequently complained more about the tailwheel digging in than the main gear tire size being a problem.
Maybe, surprisingly, in addition to the weight savings, you’ll find that braking is better with the smaller tires if that matters to you. But anyway it’s such a cool thing that with experimental aircraft, you alone get to decide what works best in your opinion.
Art,Sonex taildragger #95 (small tires with pressure recovery wheel pants, almost no grass runways in California)
I have the Air hawk (Cheapest option I could find @ $108 usd each) 6 ply tires, flown these since new so I don’t have a comparison. When these wear out, I will replace them with the 4 ply version to save a bit of weight. I have been running them at 50Psi without any issues. And yes, I too find it strange that the tubes cost more than the tires…
I also have the Anson tail wheel which saves around 700 grams over the light weight 6" upgrade if my memory serves me correctly.
When I told Peter Anson about how much weight it saved, he responded with “air is lighter than rubber? Who would have thought!”
I don’t get any of the tin canning noises that others have complained about (which I believe is eliminated by using the air tire) and it seems to handle the grass well and although I never tried flying with the standard setup, I am happy with these.
I found it a bit strange that depending on the site I looked at some gave the same weight for the 4 & 6 ply versions. My AI assistant noted that the ply rating is just a number and that the two ratings could be the same weight. I still believe the lower ply rating would save a bit of weight but I have the 6 ply as the 4 ply was not in stock.
I haven’t done calculated measurements as of yet but the difference in speed over a few flights doesn’t seem to be much i.e. 2 or 3 mph. I can live with that …
Having flown with the 500-5 Air Hawks for a few hours I learned that I should have put on these larger tires earlier. We had another Young Eagles Fly-in last weekend and flying young, future pilots off of the grass field with the larger tires (and a 5" tail wheel) was uneventful and the plane handles grass and pavement very well.
I do notice with the larger tires that the TOB brakes are not quite as effective but the difference is quite negligible.
I did lose a few mph in cruise but the small amount was worth the trade off. I have some Van’s pants that I may try and add but that’s way down the lists of things to do.
If there’s a real downside … landing on the still quite damp early morning turf field proved to me that I now will have more “bottom of the wing cleaning” to do …
I don’t know of any source for off the shelf PRP to fit the stock Sonex tires. I have a set of the older pressure recovery pants that were used on the nose wheel of Van’s RV12 aircraft. I believe that now you have to be a Van’s builder to buy such items from them.
James aircraft comes up as a possibility but their website appears to be not working at present …
“What’s the difference between Air Hawk and Air Trac?”
A summary from my AI assistant give this (edited):
Air Trac tires specialize in soft-field use with a unique narrow and oval shape, whereas Air Hawk tires provide a more robust and durable option suitable for broader applications including harder surfaces, with enhanced tread wear and casing strength. Air Hawk are FAA approved and are generally considered a step up in performance compared to Air Trac.
I have one of these on order from Aircraft Spruce, they look sort of PRP. Wheel Pant 5 White Aero | Aircraft Spruce ® I plan to use it on my nose wheel, as I can’t stand the way the stock nosewheel pant looks. I think they are made to order, so I might have it by Christmas? Hope Dies Last…
April 2026 UPDATE: Didn’t like them. Ended up using a Sonex main gear pant for the nose gear.
I haven’t tried it, but I find it highly unlikely they will fit - they are wider, AND bigger in diameter. The stock nosewheel pant is a pretty tight fit on the Cheng Shins, and I don’t think the stock nosewheel fork will clear either the width or diameter.
