At Expo/Packet Pickup you will receive three types of rider numbers to identify you as an official entrant in the ride:
Official Rider Number (“bib”)– this contains one  TIMING DEVICE: your primary event number (mandatory).  Pin this to your LEFT SIDE on the layer of clothing you expect to finish in.   This number will be marked with a color indicating your estimated medallion time at the finish line.  The mark is required to get your medallion.  Note: the final determination of your finish time is based on the time recorded by the timing device embedded in your handlebar number.
“Seatpost” number – this contains your second TIMING DEVICE.  You must attach this to your seat post so that it hangs horizontally and is visible as you cross the finish line.  Do not bend, fold or cut this number or cover it with tape.  If you fail to mount this number properly your time may not be recorded. It is also the ID number for FinisherPix who will be on hand at the finish and on the route snapping you in action.
Helmet number –to be placed on front of helmet. The rider/bib number is for results and medallion distribution.  This helps identify you in photos!