Ten years ago most road races handed out plastic shoe chips that you had to return at the finish. Today almost every timed race uses a chip you never notice: it's built into your bib. Here's how that works.
RFID in one paragraph
A timing chip is an RFID tag — a tiny antenna and microchip with a unique ID. At the start, finish and any split points, a timing system sends out radio energy through antennas in mats or on stands. When your tag passes, it uses that energy to send back its ID, and the system records the exact moment it heard you.
Bib-tag chips (what we use)
We use UHF RFID bib-tag chips from race|result. The tag is a thin foam-backed antenna on the back of your race bib. Because it's passive UHF, it has no battery and costs little enough to be disposable, so there's nothing to return after the race.
- No chip return line at the finish, and no lost-chip fees.
- High read rates when the bib is worn properly — leading UHF systems report read rates above 99.8%.
- Every runner gets chip time from start and finish mats, plus splits wherever we place antennas.
How to wear it so it reads
The human body absorbs radio waves, so placement matters:
- Pin the bib on the front of your torso, flat and visible — not on your back, not on a jacket you'll take off.
- Don't fold, cut or crumple the bib; that can break the antenna.
- Keep it outside layers and away from metal (belt buckles, foil blankets).
Shoe chips vs. bib chips
| Shoe chips (older) | UHF bib tags (current) | |
|---|---|---|
| Return after race | Usually yes | No |
| Cost per runner | Higher (reusable hardware) | Low (disposable) |
| Where it's worn | Laced into a shoe | Built into the bib |
| Best for | Some multisport events | Road races, trail races, cross country |
What about track?
Chips are great for road racing, but track sprints are decided by thousandths of a second, so track uses photo-finish cameras instead. See fully automatic timing explained.