Seatra's ERA 289FIA in production

[seatra]

Progress on 2164 has been slow but steady. I took the body prep and paint first route and most of my time has been spent sanding then filling, shaping, then primer and sanding, then another primer application and sanding, then sanding, and more sanding... I'm almost ready for the color coat now. While taking a break from sanding I saw a thread about Trigo FIA wheel fitment. I have 6-pin drive hubs and Trigo FIAs. The rear axle is all set and ready for installation. The front hubs are mated to the rotors and waiting for install after paint. I took one of the front rotor/hub assemblies and mounted it on a front wheel. I installed the wing nut hand tight and was only able to engage about half the treads of the nut. The flange portion of the hub sets firmly against the wheel mounting face. It appears that the threaded portion of the front hub is too short or the wheel center section is too wide. Curious about the rear wheel fitment, I mounted a rear wheel to the rear axle hub and engaged nearly all the wingnut threads. Although they are shaped differently, I placed the front hub next to the rear hub and they looked similar in thread size and placement. This led me to take a closer look at wheel differences. I took the rear wheel and mounted it on the front hub assembly. Fitment was similar to the rear axle hub with nearly all wingnut threads engaged. Clearly, the front wheel mounting surface to the outer face is wider than the same area on the rear wheel. My crude measurements confirm that the front wheel is approximately 5/16 inches wider. I triple-checked the fitment of the front 6-pin hub on both front and rear wheels and the mounting flanges are snugged up together. The photo on the left side is the rear wheel on the front hub and the photo on the right side is the front wheel on the front hub. Maybe I'm missing something but I can't believe I am the first to have this issue. What's the solution? I don't think I want to be running front wheels with only half the wing nut threads engaged...