Silly question about riding uphill

[Zippinalong]

I'm watching the Vuelta a Espana and I notice (actually noticed this watching the Tour de France too) that the riders weave as they go uphill. They are on the left hand side of the road then at some point the move across to the right, then at some point the move again to the left. Doing this all the way up the hill. Why do they do this?

[nscrbug]

I'm watching the Vuelta a Espana and I notice (actually noticed this watching the Tour de France too) that the riders weave as they go uphill. They are on the left hand side of the road then at some point the move across to the right, then at some point the move again to the left. Doing this all the way up the hill. Why do they do this?

I've read that zig-zagging up a steep hill makes it easier to climb since the rider is going sort of horizontally across the road instead of straight forward up the incline. It's great for those pros since they are riding on a closed course and can do that safely. But if you or I tried to do it, we would have to make certain that there was no traffic in either direction.

[pll]

I'm not sure what segment of the race you were watching, but I think it's not so much trying zig zag up a hill. Instead, they are going a bit faster than most of us and they are optimizing their line for the curves and turns in the road. That is what is going on in this long clip from Flemish TV: http://www.youtube.com/watch?v=yyeRfrAFS0Y (those are the last 6km of today's stage in the Vuelta). Over in the USA Challenge in Colorado, we saw a cat and mouse game, where on rider, Ten Dam (Rabobank), kept trying to escape with a quick acceleration moving away from the other 3 riders in the break.

[Biciclista]

but it IS easier to zig zag up a hill, that's how I used to ride up hills on an old single speed as a teen!

[pll]

but it IS easier to zig zag up a hill, that's how I used to ride up hills on an old single speed as a teen!

Not denying that at all... it's just that I don't believe that was going on in the race. As a matter of fact, they rode a fairly straight line in the final climb, which has at least one ramp with 28% incline.

[Eden]

pll has it right - they are more trying to optimize their line through the curves - taking the shortest distance and/or trying to shake competitors from their wheel. It can take only a little gap to cause someone to expend that extra little oomph that pushes them over the edge and causes them to pop....