One surprise that catches many first-time builders who have finished their projects and turned into flyers is short tire life. While some of this can be explained by a new pilot learning to fly (and test) a new airplane, the actual explanation is much simpler. Your new airplane has "old" tires!
I was reminded of this the other day when our Tundra partner sent me a picture of our "new" tailwheel with a huge aneurism in the tread and sidewall. Since the airplane only has about 70 hours on it, he was shocked to see this kind of damage, and I think he might have quietly been wondering if he did something wrong. Jim has been going through transition training, including lots of landings and take-offs. That can wear things out, but not to this extent.
The truth is, while the airplane has only been flying for a little less than a year, and has less than 100 hours on it, the tires are as old as the kit which is closing in on better than twelve years. Twelve years of the tires sitting, inflated, with weight on them. Twelve years of ozone exposure. Twelve years of having various things dripped and dropped on them. No - these aren't new tires. Without getting any significant mileage, they are practically timed out (chemically), and things like separation and delimitation aren't unexpected.
I have owned airplanes long enough that I've accumulated a nice stack of old tire carcasses over in the corner of the hangar. When I'm working on a new airplane, I try to keep the tires that came with the kit safely tucked away in storage, using old, worn out, "roll-around tires" on the wheels during construction. When it comes time to get ready for the first flight, the baby gets a new set of shoes, and the roll-arounds go back in the corner.
Something to think about—especially when those "new" tires are disappointing you.