Testing larger "bushwheel" tires on the STOL CH 750

by Sebastien Heintz

Jul 1, 2009

Those of you who have visited the Zenith factory lately have noticed the larger bald tires on our STOL CH 750 demonstrator. We've been testing these "off airport" tires this past month and are quite pleased with the results.

These affordable (non aviation) ATV tires are smooth and treadless (21x12-8) measuring about 21-inches tall. Mounted on an 8-inch Matco wheel, these larger tires raise the height of the airplane by close to 2-inches. We did not change the standard nosewheel (continuing to use an 18-inch tire).

The standard tires (shown above) supplied in the kit measure about 18-inches tall, and are mounted on 6-inch Matco wheels). This ATV tire that should meet the needs of most sport pilots wanting good off-airport capability, without the weight and cost of the larger Alaskan Bushwheel AIRSTREAK tires. (Do note that these Airstreak tires do provide much better off-airport capability to those that do need it).

We like the look of these new tires on the STOL CH 750! The tires are Nanco N800 21x12.00-8. We bought ours through Infinity Powered Parachutes, but they can also be purchased online through gearworksracing.com or ATVtires.net.

These larger tubeless 21-inch ATV tires make landings and taxiing smoother on grass or dirt fields (with 5 - 10 PSI), and other non-prepared landing strips such as beaches. (Note that these tread-less tires are not made for paved runways). We've only noticed a slight decrease in cruise performance (2 to 5 mph). Here's a YouTube video clip of the larger tires in action:

  • Taylor Ogden

    Looks good! Thanks for the pics. What's the weight carrying capacity? Would they work for an 801?
    It's mentioned that it raised the height of the airplane, but nothing was done with the front wheel, so I guess the stance of the plane on the ground is more tail high than before? Doesn't that put the prop closer to the ground?
    I always figured that if I put "tundra tires" on my 801 that I'd have to at least space the front wheel down to keep the prop up.

    Jul 2, 2009

  • Zenith.Aero

    The larger tires raised the plane by a couple of inches, but actually not that much (due to the low pressure). You're right that if raising the main gear significantly you'd also want to raise the nose (larger tire, longer fork, or longer nose strut or space). For the 801, you'll want to use a tire rated for the higher weight (and speed).

    Jul 2, 2009

  • Sebastien Heintz

    STOL CH 701 builder Elmer Weston of Alaska recently installed these tires on his 701. He's posted some good before / after photos.

    Aug 19, 2009