RECOMMENDED CHIP-TIMING SETUP FOR A BIKE RACE

by Vesa SuomalainenFriday, September 25, 2015 11:02 AM

The new LLRP chip-timing support in Webscorer PRO 2.1 was thoroughly tested at the 2nd biggest cyclocross series in the world - MFG Cyclocross in Seattle, WA.  A total of 42 heats in 6 day-long events across 28 categories and 1755 racers:

http://www.webscorer.com/mfgpresents

Cyclocross is arguably the most challenging race format for timing:

- Two of the events had more than 1050 racers
- Wave starts by category (of up to 102 racers per wave)
- Each racer doing 4-8 laps
- Lap length is just 6-8 minutes

After years of trial & error, they’ve perfected the RFID chip / antenna end of things to near 100% reliability - Webscorer adds the online & onsite registration, lap counting, lap times, website results & automated series points calculation.  

Here’s their RFID setup (pricing in USD):

$1,585 - One Impinj 4-port RFID reader
              http://www.atlasrfidstore.com/impinj-speedway-revolution-r420-uhf-rfid-reader-4-port/  
$1,460 - Four Impinj threshold antennas
              http://www.atlasrfidstore.com/impinj-threshold-lp-indoor-rfid-antenna/  
     $52 - Four LMR-195 20-ft antenna cables
              http://www.amazon.com/Times-Microwave-Connectors-LMR-195-Antenna/dp/B00K8AVRQ8  
     $10 - One Ethernet Cat5e cable 50-ft
              http://www.amazon.com/Mediabridge-Cat5e-Ethernet-Patch-Cable/dp/B001W26TIW/  
     $16 - One Power-over-ethernet adapter
              http://www.amazon.com/TP-LINK-TL-PoE150S-Gigabit-Injector-compliant/dp/B001PS9E5  
     $38 - One Linksys WiFi router
              http://www.amazon.com/Linksys-Wireless-Including-Parental-E1200/dp/B004T9RR6I  

$3,161 - RFID system cost

Use this code to get up to $50 off shipping costs when ordering RFID equipment from AtlasRFIDstore.com:  Webscorer50

Overhead truss system:

The antennas are placed overhead in a custom-made truss system that provides for an 8-meter wide finish:

$520 - Two Global Truss USA ST-132 med duty lift towers
$920 - Four segments of Global Truss F32 I-Beam Truss

$1,440 - Truss system cost

They use a custom-made reusable RFID chip that does not contain a battery (picture attached) attached to the rider’s helmet.  We had 100% tag detects with up to 80 riders going under the antennas as a peloton at the start.  The chips cost $5 each in low quantities - $4 each with volume discounts.  This is the key to the affordability of the setup - active RFID chips (with a battery) cost typically $30 or more per chip.  And no anxiety for the riders about when the chip battery runs out.

Key benefits of this setup:

1. Each chip contains two RFID tags for better detection & redundancy (programmed to the same chip ID)
2. For 100% waterproofing, the tags are placed inside a sealed plastic tube
3. Chip location in the helmet prevents interference from metal parts of the bike
4. The chip will pass very close (within 4-5 feet) of the antennas for reliable reads
5. Orientation of the antennas (pointing down) provides better timing accuracy:
  - The antennas will read the chip +/- 2 feet of the antenna at helmet height
  - A rider traveling at 22 miles/hour will cover 3.3 feet in 0.1 seconds
  - Hence timing accuracy is roughly 0.1 seconds
  - The order of finish is correct unless riders are within 3 feet (a bit more than a wheel-length apart)

This is a well-tested RFID setup for mountain-biking, cyclocross and road biking events - which are often most challenging to time with chips.  

And cost-effective:

- Use best-of-breed RFID reader & antennas acquired without a middleman
  (both MyLaps and ChronoTrack use Impinj RFID readers)
- Dual-tag chips that cost a fraction of the expensive active chips with a battery
  (we're working with the chip inventor to make these available for sale online via Webscorer.com soon)
- Webscorer PRO running on an iPad or Android reduces the registration, timing & results costs

PHOTO 1: 4 Impinj antennas attached to the overhead structure, spaced evenly across the 8-meter wide finish / lap lane

 

PHOTO 2: The chips are attached to the riders' helmets with zip-ties

 

 PHOTO 3: Wave starts by category of up to 80 riders

 

PHOTO 4: Custom-made RFID chips in a waterproof housing 

 

PHOTO 5:  The Impinj reader located close to the antennas to minimize the power loss to antennas

 

PHOTO 6: Timing crew monitoring chip detects on the iPad screen (WiFi router is on the table)

 

PHOTO 7: Racers line up to do online self-registration and pick up their bib & chip

Webscorer Blog

The main purpose of this blog is to provide supplemental "how to" documentation for various registration, timing and results scenarios and to provide feature news and discuss product issues. If you'd like us to write a blog post about a topic, please drop us a note on our Facebook page or send us an email at support@webscorer.com.

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