# Following car could influence TT times.



## jarlrmai (1 Jul 2015)

The UCI rule for following vehicles is 10 meters. This study indicates that a vehicle following at 10 meters could provide a 4 second advantage to a rider over 50km at top level TT speeds.

http://www.urbanphysics.net/2015_JWEIA__BB_YT__Car_Cyclist_POSTPRINT.pdf

It calls for the distance to be increased to 30 meters.


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## oldroadman (1 Jul 2015)

This only matters in pro racing, and as everyone in contention has a car following, no advantage is gained. Plus, who can enforce 30 metres - even 10 metres is a challenge for the commissaires, I think, and there is not a commisssaire in every car all the time. Nice bit of research, but of little consequence. What happens in crosswinds, and I've never ridden a TT in still air, never mind corners, climbs, descents. perhaps UK testers should do some research about how traffic flow on their beloved "fast" (or dodgy)courses affects their performance? I can't see CTT wanting to do that. The only "race of truth" TT is on a closed road.


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## jazzkat (1 Jul 2015)

oldroadman said:


> The only "race of truth" TT is on a closed road.


Yes, very true, but even then it's not always a level playing field.
A few years ago I did a TT where I got a much better time than a friend of mine (notice I didn't say beat because he rode hours later than me) because the wind had got up and slowed the later riders down, there is no way I would beat him in a side by side, flat out race.
You could argue that there is no real way of doing a truly equal TT style ride outside in the elements where wind can come into play.
But it's the best we have and it's just the way it is. I can't see there's a way to change it and make it any more a level playing field than it is now.
It's a well known fact that lots of traffic "chops the still air up" making for a faster ride.


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