What fun! Did you ride Jun? I’ve got to try one of these events in this area. Just curious; do you know if they’re using Kold Kutter ice studs? I’ve recently learned about them from a guy who used to race motorcycles on ice. They’re about $20 for 250 studs.
Kold Kutters (manufactured for motor-bikes) screw from the outside into a knob. Most of the racers use 700c tires which are not knobby enough to handle the length of a Kold Kutter. I’d be interested in seeing how well they would work if mountable (perhaps on a mountain bike). One advantage would certainly be less risk of a flat as there would be no metal inside the tire and no need for a liner.