Novice question about race timing

[hollowd]

I'm an injured runner who's started to cycle at the beginner level and was wondering about the timing system used at large bike races like the Tour de France. At most major marathons the participant uses an electronic chip that plots splits and finishing times and are computer generated. After watching the tour day by day I'm confused how the announcers Liggett and Sherwin know how these hundreds of riders stand against the clock and against each other at just a glace! It's got to be computer generated but I don't know how they do it! Do the riders wear electronc chips like the runner's do? If not, how do they do it?

 

[Daremo]

Nowadays the motorcycles and race officials probably use GPS, and they can interpolate based on speed and such how far apart the riders are.

At the finish, there are always time clocks that show the race time, and the announcers do a quick subtraction to get the differences.

In a bunch sprint, everyone ends up getting the same time whether they finish first or last UNLESS there is more than one full bike length of separation in the field as it crosses, then the times are broken up between the different groups.

Phil Liggett is constantly off in time gaps ........ the announcers are no different than us, they just have the time gaps that are reported to them on race radio during an event ..........

 

[tafi]

Any rider who finishes within one second of the rider in front will be given the same time as the rider in front.
In terms of time gaps, you will notice that at the Tour, gaps and splits on the road are only given to the nearest second.
This leads me to believe that the motor cycle time keeper just uses a stop watch and a fast motor bike!
Time gaps are also measured at landmarks along the way (sprints climbs major towns etc)

Fractions of a second only come into play in close finishes (where you can use a photo anyway) or in time trials.

I'm not sure how you would use GPS when the bikes aren't fitted with any timing equipment.

 

[Daremo]

The motorcycles and race official cars are .........

 

[ouzo]

in SA we have to of the world largest timed cycling events w.r.t. the amount of cyclists (35 000 for the Argus and 25 000 cyclists for the 94.7)

They use a timing chip like you described with timing matts at certain locations. Not sure if they'd use the same system in TDF.

 

[Roy Gardiner]

Originally posted by hollowd
It's got to be computer generated but I don't know how they do it! Do the riders wear electronc chips like the runner's do? If not, how do they do it?

Photo record of each rider as he crosses the line gives day's times, computer then take over to give the total time so far. All commentators have them.

During the day the time gaps are much more approximate, calculated by the race organisaition using magic

 

[drewjc]

im not 100% sure about the tour but u will notice in a lot of big races the riders have a small (usually red) object hanging off the side of one of their front forks. I believe this is used to convey a riders position as they cross a timing matt at the finish line.

I do believe that cameras also do have an important influence on the timing of stages in tours aswell (especially if individual timing devices are not used)