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....

[pll]

Here I found a diagram of the lines through a curve, the yellow path being the ideal one:

This comes from a blog write up about cornering technique (http://realanalytics.wordpress.com/2...ring-analysis/)
You can see this in action by watching Fabian Cancellara in a descent; it's a clip I have linked before... you can really see how he changes his line in anticipation of each curve, how he leans into it, etc:
http://www.youtube.com/watch?v=RxXqQqAc2pA

[jessmarimba]

I wish I'd seen this before trying go-kart racing the other day. My coworkers kicked my butt!

[maillotpois]

That diagram is fantastic for explaining cornering at speed - descending or riding twisty roads on a motorcycle, etc. But for choosing a line climbing it doesn't really apply. Climbing cornering lines are really more a factor of road gradient, debris in the road, etc.

[smilingcat]

I zig-zag up a very steep hill to find the gentlest climb it means I'm riding bit farther but when you are on a super steep hill, I'm looking for ways to relieve the steepness.

For instance on a very steep hairpin turn (180degree turns), I go on the outside not on the inside. The difference can be 25+% grade on the inside turn while on the outside it might be down to 15% grade. It's the difference between being able to climb or get stopped!

Another reason to zig zag on a hill climb is sometimes you are looking to launch yourself away from those are riding your wheel on a race. By making these moves, you are hoping to drop the guy behind you. You are hoping that the guy behind you hasn't been paying attention to the subtle grade difference on the road so that you are launching off on a easier grade while the guy behind you has to try to catch you up by going up a steeper grade...It's also mental too when you are trying to shake off the guy behind you.

And if you are on a straight steep hill zig-zagging will reduce the grade because you are traveling more. I was just doing that zig-zagging up cause it was just too steep and I was blowing up.

[gnat23]

Another reason to zig zag on a hill climb is sometimes you are looking to launch yourself away from those are riding your wheel on a race. By making these moves, you are hoping to drop the guy behind you.

This is, of course, what I *say* I'm doing.

-- gnat! (but really I'm swerving like a cross-eyed drunken paperboy hoping I have a few calories left to clip out, if suddenly necessary)

[luv2climb]

Here's a perfect example of one of the very few times I've had to do this. The last half of this vid shows me climbing a hill with grades up to 25% on my single-speed 16" wheel Dahon Da Bike folding bike. I had to "tack" the hill on the steepest parts in order to make it up.

Be forewarned, there is very heavy breathing in this video due to the effort involved. Also, I crash at 1:13 when the handlebar latch comes undone when I attempt to climb out of the saddle. This causes me to laugh uncontrollably, even after resuming my climb.

http://www.youtube.com/watch?v=ow_8b-7AfN4

[suzbyrd]

The professionals zig zag going up a hill because they are either A)trying to see where the competition is, or B)trying to drop someone off their wheel. They hardly ever zig zag because they are bonked or its too steep. Yes, we may have to zig zag to make it easier, but these guys are highly trained and they wouldn't do unless for strategy reasons.

[Seajay]

Smiling Cat has it.
Often on steep climbs the inside line is REALLY steep....in order to stay on top of a gear and maintain speed, often you will ride to the outside.
You really don't see the pros "tacking" up hills. Maybe a bit of weave only because they are putting a lot of upper body into keeping a particular gear going...but that's about it.

[Catrin]

This is an interesting thread. On a related topic I TRIED to start going up a little hill on a mtb trail the other day...and lifted the front wheel off the ground in the attempt I walked it to the top and then started....