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ABI-13889 – Alaskan Bushwheel 1-1/2 Inch Bearing Cone
Available now on the Airparts.aero Marketplace.
The ABI-13889 is a high-performance tapered roller bearing cone specifically engineered for the extreme service environments of backcountry and "bush" flying. Manufactured by Alaskan Bushwheel (ABI)—a division of Airframes Alaska—this 1.5-inch bore bearing is a critical component of the heavy-duty wheel assemblies found on STOL (Short Takeoff and Landing) aircraft.
Designed to withstand the massive lateral "side-loading" and high-impact forces of off-airport landings on gravel bars, tundra, and beaches, the ABI-13889 is built to a higher standard of durability than standard industrial bearings. It features precision-ground rollers and a case-hardened steel composition that allows for the simultaneous management of Radial Loads (the weight of the aircraft) and Thrust Loads (lateral forces during ground loops or uneven terrain).
Key Features
Bush-Flight Ruggedized: Engineered to handle the unique stress profiles of oversized 29", 31", and 35" Alaskan Bushwheels.
Precision Tapered Geometry: Allows for adjustable "end-play," ensuring the wheel spins freely while maintaining absolute structural rigidity under load.
High-Vacuum Degassed Steel: Utilizes premium alloys to minimize internal impurities, significantly reducing the risk of "spalling" or premature fatigue failure in the field.
Compatibility: Standard 1.500" bore size, making it a direct replacement for legacy 13889 bearings in ABI and Cleveland-style high-performance hubs.
Optimized Cage Design: Features a heavy-duty retainer that keeps rollers perfectly aligned even during high-heat braking or low-speed "tundra taxiing."
Technical Specifications
Part Number: ABI-13889
Manufacturer: Alaskan Bushwheel (Airframes Alaska)
Component Type: Tapered Roller Bearing (Cone/Inner Race)
Bore Diameter (d): 1.5000 in (38.10 mm)
Width (B): 0.6500 in (16.51 mm)
Material: Case-Carburized Aerospace Steel
Matching Cup (Outer Race): Typically pairs with ABI-13830 or equivalent.
Certification: FAA-PMA Approved
Aircraft Compatibility
Piper Super Cub (PA-18): The standard for heavy-duty bush conversions.
Cessna 170, 180, 185 Skywagon: Critical for aircraft utilizing ABI 6-bolt or 10-bolt high-performance wheels.
Backcountry STOL Aircraft: Common on Carbon Cubs, Just Aircraft (Superstol), and various Kitfox configurations.
Note: This bearing is specific to 1.5-inch axles. Always verify your axle diameter before ordering, as some legacy "small" bush planes utilize 1.25-inch hardware.
Why Choose ABI-13889?
In off-airport operations, a wheel bearing failure isn't just a maintenance headache—it’s a recovery nightmare. The ABI-13889 is chosen by bush pilots because of its superior Impact Resistance. Standard bearings are often prone to "Brinelling" (permanent indentation of the races) when a heavily loaded aircraft hits a rock or rut. The ABI-13889’s specialized heat-treatment process creates a "ductile core" with a "glass-hard surface," allowing the bearing to absorb shock without cracking or deforming.
Maintenance & Installation Addendum
The longevity of an ABI-13889 is entirely dependent on Grease Integrity and Preload Adjustment.
Pro-Tip: In the bush, water and silt are the primary enemies. When installing the ABI-13889, use a high-pressure water-resistant grease (e.g., AeroShell 22 or Mobilgrease 28). Ensure the bearing is "packed" until grease is forced out between the rollers and the cage.
Torque Note: When installing the axle nut, tighten until all "play" is removed and a slight drag is felt when rotating the wheel, then back off to the nearest cotter pin hole. A "too tight" bearing will overheat and fail within miles; a "too loose" bearing will allow the wheel to wobble, destroying the grease seals and the axle.
Note: The ABI-13889 is a flight-safety component. Always inspect for "pitting" or "bluing" (heat damage) during every 100-hour or annual inspection. Installation must be performed by a certified A&P mechanic.
