Wearing Your Race Number

You have paid your entry fee, trained hard, run the race. The last thing you want to happen is not get a time! This page give your guidelines to minimise the chances of this.

There is quite a lot of information on this page so if you dont have time to read it all just follow the GOLDEN RULE

When you cross the timing mats at the start and finish, ensure that your chipped race number is not folded IN ANY WAY and that the whole race number is COMPLETELY visible ie not unobstructed by things like phone or water bottle pouches, hands over it as you start/stop your watch etc etc. It’s that simple!

If that is all you need to know, then you don’t have to read on. However, if you want to learn a bit more about the reasoning why, read on 🙂

Folded Numbers

There are a couple of reasons why you must not fold your number

1. The communication used for timing events with chips on bibs is UHF RFID. It is very effective but one drawback is that the UHF signal is affected by water. As your body is 90% water , we have to minimise the effect of your body on the chip that is very close to your skin. We do this by sticking the thin metal RFID chip on the back of the race number and then putting foam “spacer” over it. This effectively acts as a barrier between the chip and your “watery” body. If you fold your number horizontally and the chip is part of that folded portion, the chip is now in contact with your body, with the foam spacer now on the outside and basically redundant. That can increase the chances of your chip not being read

2. Sponsor logos and names are often on the race number. The contributions made by sponsors often subsidise the cost of your entry fee, or pay for the prizes. For this generous contribution, they deserve visibility on the the race numbers. Folding your race number removes that visibility which, in my eyes, is unfair.

Wearing a phone belt that covers the bottom of the race number

Phone belts are becoming more and more popular and, worn correctly, there should be no issue with chips being read. You just need to ensure that the phone belt is not covering any part of the race numbers, especially the bottom quarter. This is because your phone , or water battle, could block the signal to the chip that is is covering

Wearing your race number on your back

This is not as critical as the two situations above, but it is not the ideal place to wear your race number. Firstly, the race rules normally dictate that your race number should be worn visible on your chest. Secondly, if your race number is on your back, you are reducing the time that the mats can detect you by at least 50%, due to your body totally blocking any signal until your are actually over the mats. This is not normally a problem, but can be in high volume starts where the chip benefits from as much “exposure” as possible.

Wearing race number on the side of your leg

This causes a couple of issues. Firstly, people who wear their race number on the side of their shorts inevitable have to fold it, both horizontally and vertically. So you run the risk from scenario 2 above. Secondly, if the race has a commentator with a tablet that gets updated with finishers details as they pass a point about 50m from the finish line, there is a good chance you will not be detected and therefore miss out on a name check. Often, the equipment used to detect finishers near the finish line is only on one side, in order to minimise any obstruction to the runners (and to make it look less like a finish line so people dont stop 50m from the finish). If you wear your number on the side that is away from the equipment, the “body water law” comes into play again.