These Replacement Gear Legs are constructed from 1/4" wall seamless chromoly tubing. They are lathe turned with a double tapered outside profile
that allows the entire length of the leg to flex evenly, providing maximum shock absorbtion at minimum weight. (This is the same approach that Cessna is
using on their new C-162 Skycatcher gear legs). These gear legs feature TIG welded axle receivers and are supplied with 3/4" chromoly insert axles to fit
our C-90 Hydraulic Disc Brakes, and either Azusa's 5" & 6" TriStar wheels or our 5" & 6" Premium wheels. Heat treated to 190,000+ PSI tensile strength.
Supplied painted with 2 coats of grey ZeroRust. NOTE: The Thorpe T-18, with hundreds of owner-built examples flying for 30+ years, features a landing gear
constructed of heat treated, heavy-walled Chromoly Tubing. (See "Landing Gear Design For Light Aircraft, Volume I" by Ladislao Pazmany, page 163). Price is
per set of 2 legs & axles
I began the development of our heat treated chromoly gear legs after reading a comment from one of the principals at Sonex: He stated that titanium had different bending characteristics than other engineering materials, and so didn't need to be tapered to provide a proper spring action. I obtained a copy of Ladislao Pasmany's "Landing Gear Design for Light Aircraft" and studied the design of rod and tubular landing gear legs. I found that taper is an important factor, as it allows for the bending stress to be distributed over the length of the gear leg instead of concentrating the stress at the point where the gear leg emerges from the receiver tube. Also, if the receiver tube is fairly long, a second taper can be machined into the gear leg, allowing the leg to flex both above and below the exit point of the receiver tube.
If the gear leg is fabricated from tubular material rather than solid stock, a significant reduction in weight can be achieved without sacrificing either strength or durability.
In my research into titanium I found that there are a number of alloys available, and the tensile strengths of these alloys vary widely, with 195,000 PSI being the highest available strength. When I selected the heat treating schedule for my gear legs, I specified a hardness of RC-42, which gives a tensile strength of 196,000 to 198,000 PSI.
While titanium is about 40% lighter than chromoly steel, the combination of the use of heavy walled tubing, the amount of material removed when machining the tapers, and the integrated axle receiver with heat treated insert axles results in a product that is equal in weight to the un-tapered titanium gear legs with the heavy and under-engineered Sonex factory axles, and is much superior to the factory supplied products in performance and durability.
NOTE: Items are not refundable