How are race numbers in cycling races assigned?

Question

In cycling races all riders wear race numbers for easier identification. Are there som rules or traditions which decide which team gets which set of numbers?

By looking on some races, it looks that number 1 is assigned to the past winner, if they start again this year. But I am not sure how it works with higher numbers. I am also not sure what happens if the last year's winners does not start. Also, does it depend on the cyclist who won last year or on the team who won the previous edition of the race? If there are rules about this, are they different for stage races and one-day race?

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For example, looking at 2016 Tour of Flanders startlist, the winner from last year was wearing number 1. But the rider who was the 2nd last year was wearing 25. The 2015 winner John Degenkolb could not race in 2016 Paris–Roubaix due to injuries. But his team still received the first numbers in the 2016 startlist.

When I look at this year's Giro d'Italia startlist, the teams seem to be ordered alphabetically. The reason might be that the last year's winner does not participate in Giro this year.

The defending champion Nairo Quintana did not race at this year's Tirreno-Adriatico. In the startlist, the first race numbers were assigned to Tinkoff team and then it seems to continue alphabetically.

Answer 1

Generally speaking, race numbers are a rider's ID, so they're issued sequentially to people who sign up.

But, it depends totally on the race - there may be specialist traditions unique to the event.

If the race is expected to have 90 to 899 riders, the numbers will probably be 3 digits, and will start at 100 or 101 and go to 999.

For races with 10 to 89 riders, numbers may be 10 or 11, to 99.

It's not unusual for the organisers to drop specific numbers either. These race IDs are often excluded:

• 666 ("number of the beast")
• 111 (emergency services number)
• 999 (emergency services number)

Sometimes 777 and 888 are dropped, because they're perceived as lucky in some cultures. Likewise 13 and 1313 may be excluded as unlucky numbers.

Although UCI regulations prevent you from altering your race numbe , it's considered acceptable to rotate it if you do draw #13 says

If you draw race number 13, turn it upside down.
Paradoxically, the same mind that holds such control over the body is also woefully fragile and prone to superstitious thought. It fills easily with doubt and is distracted by ancillary details. This is why the tape must always be perfect, the machine silent, the kit spotless.
And, if you draw the unlucky Number 13, turn it upside down to counter-act its negative energy.