Yes, there is a box that measures wheel diameter and crank length for both 20/100 and 24"/125mm. If the tire doesn’t fit easily, then it’s too big.
For track in Europe there are 2 timing methods: 1) there is a booth where you get a sticker at any time (say starting at 8:30) and when checking in at the starting line they check for the sticker on the cranks (and send the few who forgot to the booth to measure quickly). Here you could know hours in advance or 2) they check as they call your start number (CFM 2025 France did this). However, you should be allowed to check earlier, especially between races, so I would think it would work.
Good to know, thanks. I’ll maybe chance taking the 2.1 tyre and check at registration if/when I can get it measured. That would give me until the Sunday to swap it if it doesn’t fit since the first race I’ve entered is the criterium.
Though to be honest I’m probably overthinking things, realistically I doubt if I’m fast enough for an extra couple of millimeters to make much difference and I’ll be competing for fun rather than for medals!
Why do they only allow cranks longer than 125mm? At the moment the only cranks longer than 125mm that I own are the Kris Holm Boundary double hole cranks that are only compatible with my muni wheel and the ones in my giraffe (though I’m not sure you’re allow to race with a giraffe), so I will only participate in coasting and maybe ww and stillstand despite already planning to travel with 3 unicycles.
Also, I’m unsure of how do they apply the rules for coasting. They state that touching the wheel is not allowed, but when I’m coasting (either 2 foots or 1 foot in crown) with a trials unicycle I very often touch the tire by mistake while fighting for balance and grip. How could they tell with enough confidence to disqualify me that I did a small touch at some point during the run?