Pursuit timing

[kcass]

Something's been really bugging me while watching the pursuits - the clock doesn't stop when the leading team goes over the (thin, white) start/finish line but when they've just gone out of shot.

Towards the end of the womens' pursuit there was a wide shot as GB were catching up with the USA and the clock stopped when GB went over the thicker white line at the end of the straight.

Which is the finish line? If its at the end of the straight shouldn't they be starting from the same place? And shouldn't the camera be there?
If it is the line half way down the straight why doesn't the clock stop then?

Please help - its keeping me up.

[spesh]

The timing is from the third rider to cross the pursuit (start/finish) line halfway along the straight. That's why they try to cross the line at the end of the race side by side.

EDIT:

From the UCI regulations for track events, page 17:

3.2.080 The time and the classification of each team shall be taken on that of the third rider of each team.
The time shall be measured on the front wheel of the third rider of each team.

[kcass]

I know - thats not what I'm talking about though.

In the omnium pursuit at the moment they've got it right. The clock's stopping when the rider crosses the line.

[philip]

The broad white line with a narrow black line is the sprint finish.  It's not in the middle of the straight and is not used in the pursuit.  The narrow white line in the middle of the straight is the pursuit finish.  The pursuit is timed on the front wheel of the third rider and the TV coverage appears to have a small delay between the picture and the on-screen clock.

[kcass]

the TV coverage appears to have a small delay between the picture and the on-screen clock.

Which there hasn't been before in all my years of armchair pursuit watching. It just looked weird.

[Pingu]

the TV coverage appears to have a small delay between the picture and the on-screen clock.

Which there hasn't been before in all my years of armchair pursuit watching. It just looked weird.

And sometimes the timing doesn't give the split between the teams 

[mattc]

Related question (perhaps!):
How come Ed Clancy's Omnium flying lap (11.x) is slower than (say) Kenny's last lap from a slightly slower start? (10.x)

(numbers from memory, subject to error!)

[David Martin]

Clancy's flying lap is 250m. Kenny's is 200m

[mattc]

Ta! (you can tell me why if you want bonus points)