ASK THE MXPERTS: IT’S A BURIED SECRET

IT’S A BURIED SECRET

Dear MXperts,

At a local race I was standing by the finish line when two 450 Pros were side by side at the finish line. When they hit the jump, the KTM guy was definitely in front of the Yamaha guy as they passed the checkered flag. The announcer said that the rider who was half a bike length behind at the flag was the winner. How can this be?

Modern motocross races, local and national, are scored electronically by a transponder mounted behind the front number plate on every bike in the race. Each transponder has its own unique code that can be read every time it passes over the loop antenna buried in the face of the finish line jump. That code is transmitted to the scoring tower’s computer system, which logs the bike in its proper place.

Sadly, the checkered flag is more ceremonial than an accurate gauge of who won. The actual finish line, where the race is scored, is not on top of the finish-line jump (where the flagger stands), but on the face of the jump. Racers are scored when the bikes cross the open-loop antenna, which can be 10 to 15 feet before the checkered flag. Why don’t they put the transponder antenna on the top of the jump? The transponder will not work if the bike is in the air, because it gets too far away from the wire’s electronic pickup. Thus, the wire has to be buried in the face of the jump at a spot where the suspension is compressed downward. It cannot be at the top of the jump, because if the rider pre-jumped or seat-bounced, he would not get scored.

No one is happy that the fans cannot see where the buried wire is, which means that they cannot judge for themselves who won the race, but such is the price we pay for being a slave to science. 

ASK THE MXPERTS: IT’S A BURIED SECRET Motocross Action Magazine.