It is essential to know the rules of the game.
As a commissaire, I could give you countless examples of riders being penalised for doing something they didn't know was against the rules. Months - even years - of training, thrown away for the sake of a simple, avoidable error.
The best piece of advice I can give you is to read the UCI rules before you race abroad. I mean, you should read them before doing a National or Trophy race in the UK, and you should read the BC rules and technical guide for cyclocross too. And even your league rules!
Furthermore, if you are hoping to get signed as a pro one day, then not knowing the rules is like turning up to a job interview without knowing what the firm manufactures. Riding professionally is a job and the rules are the basics of doing that job right.
I’m well aware that this sort of advice often goes in one ear and out the other. So I’m going to summarise some things that you really should know. But I’ll say it again – there is no substitute for knowing the actual rules.
You can’t ride through the pit lane without receiving mechanical assistance.
So if your bike isn’t ready, make sure you RECEIVE mechanical assistance, even if you don’t need it. Get someone to fiddle with a skewer or wave an Allen key at your bike. Otherwise a strict commissaire will DQ you. A lenient commissaire might make you stop for 30 seconds.
You can turn back if you haven't passed the second pit flag.
The pits are marked out by yellow flags. If you choose not to pit and then have a mechanical before you have passed the second flag, you can turn back. However, you must not impede the oncoming riders. So this might mean keeping to the side and waiting until you can go back without hindering people. Also, you have to return to the pit entrance, you can't nip in at the exit.
Your bike must be UCI approved for a UCI event.
This rule applies to your frame and your wheels. It is currently being rolled out - there are different timescales for different categories of rider and event. But is already active in major races that could affect you and where it applies it WILL be checked! No approved bike, no race. Approved status means that the UCI has approved the design of the frame and wheels. You’ll know a part is approved if it has a UCI sticker saying so. This must be under the lacquer, so you can’t just put a dodgy sticker on at the last minute. They'll also check your tyre width doesn't exceed the maximum, and scan your bike for mechanical doping.
You can't race with 'unnecessary equipment'
This is a bit of a catch-all term and is rarely applied, but to give an example, it means that you might not be able to race with a mudguard sticking off the back. If in doubt about an accessory you've added, check with the commissaire well before the start so you can remove it with plenty time to spare if necessary.
You must race in your team/club kit
This means the kit that the team has registered with the governing body. So you can’t wear an old design either, it’s got to be the current registered kit for the team or club that is on your racing license. You might get away with it in Belgium where they don't know our kits, but people have been DQ’d at the British national champs for wearing the wrong shorts. Don't risk it.
You can’t be handed drinks/gels
Unless the commissaire specifically allows it in very hot weather, you can’t take a hand up. However, you can always receive a drink if it is in a bottle cage on a bike that you receive in the pits. It doesn't matter if you had a bottle on the bike you dismount, or whether you started the race with a bottle. As long as it is received attached to the new bike, it's fine. The same with gels - if they are taped to the bike, or fixed to it in some similar way, it's ok.
And finally, you'll be fined if you aren't at the podium
At big events, if you are likely to make the podium, make sure you have a podium bag ready. Clean hat and jacket, shoes, and something to clean your face. If you waste time faffing about going back to your car to clean yourself up, you can be fined. But I suppose it's a nice position we'd all like to be in!