That’s a big order you’re

That’s a big order you’re looking for Jim. Here’s a couple of suggestions. It would help to know your budget, but this will get your started.

Most professional and many prosumer camcorder style cameras (not DSLRs) are capable of “overcranking” which means the shutter speed is operating at a high rate. This results in the action being slowed down during playback. A good example of what overcranking does can be seen in this video by Philip Bloom: https://youtu.be/uBP7NF2SqCs By slowing down the action, that should allow you to see who crossed the line first. By running two similar cameras, one can be your adjudication view, the other running at normal speed to record the final. Both would record to large capacity SD cards.

As for reading the numbers – where you’re an organizer, couldn’t you come up with a way to attach a paper number to each bike that faces upward? Seems simple but I know nothing of the rules.

This is going to be a challenging DIY project. Good luck.