I concur with Mike Bentley, I have the 21" Smoothies. I have landed at some remote airstrips in both Idaho, Utah, & Mississippi with them and they have held up well to my torturous landings. One of the No ID 106 - Promontory Point Airstrip, in Utah was very rough gravel, and I had no issues. The picture on the Left is Ennis Texas, 3500 Foot Asphalt, the picture on the left is Promontory Point. I've landed at Ronnie Smith Grass Airstrip at Southern Mississippi Light Aircraft & Farm. The side benefit, they will not break the bank.
I like the Web Site I found for the Promontory Point Photo, I need to explore some of the Airports listed for Texas.