Sitting in = slowing the puller???

[blaronn]

I don't claim to know more than Lance but this just makes no sense to me. In his It's Not About the Bike book (p. 234) he says:

"...Kevin's job was to get behind Zulle and stay right behind his wheel, making it harder for Zulle to pull up the hill. It's called 'sitting on him.' While Kevin 'sat' on Zulle's wheel and slowed him down, the rest of my Postal teammates pulled me, riding in front of me, allowing me to draft and catch up..."

I understand that there could be a psychological factor that impacts the puller's action, and maybe blocking efforts could prevent others from coming around and pulling the lead guy, but from the context it sounds like he's referring to some new law of physics that I'm not yet aware of.

So how does the guy in back have any physical effect on the guy up front?

[botto]

I don't claim to know more than Lance but this just makes no sense to me. In his It's Not About the Bike book (p. 234) he says:

"...Kevin's job was to get behind Zulle and stay right behind his wheel, making it harder for Zulle to pull up the hill. It's called 'sitting on him.' While Kevin 'sat' on Zulle's wheel and slowed him down, the rest of my Postal teammates pulled me, riding in front of me, allowing me to draft and catch up..."

I understand that there could be a psychological factor that impacts the puller's action, and maybe blocking efforts could prevent others from coming around and pulling the lead guy, but from the context it sounds like he's referring to some new law of physics that I'm not yet aware of.

So how does the guy in back have any physical effect on the guy up front?

he doesn't, it was merely sally jenkins exercising some poetic license.

[waterrockets]

Yeah, that's just part of the mythology that helped Lance be Lance. I'm sure he believed it slowed Zulle down, because he never asked anyone working at one of the wind tunnels he visited...

Sitting on someone's wheel physically makes them go faster. You're filling some of the negative pressure zone behind them with the positive pressure zone in front of you. That turbulence lowers the front rider's drag.

There can be an emotional effect that will slow you down, and sometimes having a guy on your wheel compromises your strategy, so those are the main reasons you send a domestique up the road with a heavy hitter.

[ElJamoquio]

I don't claim to know more than Lance but this just makes no sense to me. In his It's Not About the Bike book (p. 234) he says:

"...Kevin's job was to get behind Zulle and stay right behind his wheel, making it harder for Zulle to pull up the hill. It's called 'sitting on him.' While Kevin 'sat' on Zulle's wheel and slowed him down, the rest of my Postal teammates pulled me, riding in front of me, allowing me to draft and catch up..."

I understand that there could be a psychological factor that impacts the puller's action, and maybe blocking efforts could prevent others from coming around and pulling the lead guy, but from the context it sounds like he's referring to some new law of physics that I'm not yet aware of.

So how does the guy in back have any physical effect on the guy up front?


Your first mistake.

Lies. All of it.

[asgelle]

Sitting on someone's wheel physically makes them go faster.

Yes, but how much? Do we really care if it's 1 mm/hr?

[GatorFL]

Yes, but how much? Do we really care if it's 1 mm/hr?

I think it's effective in NASCAR. Bike racing, though....

[El Diablo Rojo]

I think it's effective in NASCAR. Bike racing, though....

Actually drafting in CRASHCAR helps both cars, especially when they bump draft.

Sitting on someones wheel might have a psychological effect that could cause someone to slow but no actual effect. Now getting into the rotation of a pace line to slow it down is a useful tactic.

[waterrockets]

Yes, but how much? Do we really care if it's 1 mm/hr?

I certainly don't care, but Coggan mentioned once that they were able to detect the effect through power file analysis on the track. It sounds like that analysis was not part of a formal study on the subject though, just random "hey, check this out" analysis, so it's not really conclusive (as to magnitude). It seems to me that if it would be enough to detect with an SRM, it's worth something (to somebody).

[merckx89]

Actually drafting in CRASHCAR helps both cars, especially when they bump draft.

Sitting on someones wheel might have a psychological effect that could cause someone to slow but no actual effect. Now getting into the rotation of a pace line to slow it down is a useful tactic.

I've heard the bump draft term before, what's the difference between that and just drafting?

[El Diablo Rojo]

I certainly don't care, but Coggan mentioned once that they were able to detect the effect through power file analysis on the track. It sounds like that analysis was not part of a formal study on the subject though, just random "hey, check this out" analysis, so it's not really conclusive (as to magnitude). It seems to me that if it would be enough to detect with an SRM, it's worth something (to somebody).

I can see how sitting on someones wheel might mess with a less experienced rider, said rider might try to get the sitter off his wheel and burn himself up. I can't believe that a rider of Zule's experience would put himself into the red trying to drop Livingston.

At the San Dimas stage race it was my job to mark the KOM leader. He tried to drop me several times and by the end he was dead and I easily beat him on the last KOM points climb and for the line. Had he just rode his own race he probably would have had more at the end.

[waterrockets]

I can see how sitting on someones wheel might mess with a less experienced rider, said rider might try to get the sitter off his wheel and burn himself up. I can't believe that a rider of Zule's experience would put himself into the red trying to drop Livingston.

At the San Dimas stage race it was my job to mark the KOM leader. He tried to drop me several times and by the end he was dead and I easily beat him on the last KOM points climb and for the line. Had he just rode his own race he probably would have had more at the end.

Yep, agree. I'm wasn't commenting on the tactics, just the aerodynamics.

[El Diablo Rojo]

I've heard the bump draft term before, what's the difference between that and just drafting?

Bump drafting is when the second car 'lightly' taps the car in front and pushes them down the road. The second car, benefiting from the draft is usually a few miles an hour faster than the lead car. Using this technique (which I believe is against the rules in CRASHCAR) the two cars can go faster. Back in the early 80's I raced a few Renault Cup races and we did that down the back straight at Riverside Raceway. It's illegal but for the most part nobody got flagged for it.

[aicabsolut]

Bump drafting requires a bit of a push from the follow car. It helps the lead car move through, and the drafter can easily follow. Done at the wrong time, the front car will get loose, and things can go horribly wrong.

I guess the best way to try to replicate it on bikes is to be drafting in an echelon and the person drafting puts a hand out and gives the leader a little bit of a push. Unlike just riding up and pushing someone from the side as usual, the draft isn't broken, and the follower just wheelsucks behind the leader. So bump drafting is used when the lead person isn't on the front of the entire group. The drafter is just using the person in front of him to gain position without giving up the draft.

It's not against the rules, but there are "no bump" zones.

[fosmith]

bumpdrafting is legal on straightaways, just not in turns. being super close in turns will cause the car in front to become "aero loose"...just watch Tony Stewart or Kyle Bush...

sitting on a wheel can slow the leading rider. he's not getting any type of rest, and when he eases to rest for a second, he slows. psychologically it's messing with him too.

[waterrockets]

I bump draft friends on descents... sort-of. I draft until I start to overtake them, put a hand on their hip, and push them back ahead of me. It's a good way of giving back some of the energy I saved in the draft, without having both of us in full wind at the same time.

[San Rensho]

I think the OP is reading too much into it. Lance means that having a guy sit on the leader's wheel forces the leader to set and keep the pace, which is usually more taxing eventually than when someone sits on someone up a hill who is setting the pace.

[dmotoguy]

I will track down where I read it, but it gave an actual percentage of energy saved when two people are drafting each other... its been a few years since I read it so I'm pulling numbers out of my ass .. but it was like a 3% advantage for the lead rider.


Here is a quick google: cycling aerodynamics for dummies (http://www.exploratorium.edu/cycling/aerodynamics2.html)

[ElJamoquio]

I will track down where I read it, but it gave an actual percentage of energy saved when two people are drafting each other... its been a few years since I read it so I'm pulling numbers out of my ass .. but it was like a 3% advantage for the lead rider.


Here is a quick google: cycling aerodynamics for dummies (http://www.exploratorium.edu/cycling/aerodynamics2.html)

Didn't read your link, but at 12 MPH up a climb, there's no measurable improvement for drafting.

[Bullseye]

Didn't read your link, but at 12 MPH up a climb, there's no measurable improvement for drafting.
I agree - no benefit for either party.

At 25+ mph, the lead rider might get a tiny [perhaps even measurable] benefit from the draft.

-bullseye

[dmotoguy]

Didn't read your link, but at 12 MPH up a climb, there's no measurable improvement for drafting.

Sorry, the original post just said hill, so I assumed they could be still at some speed.

[USAZorro]

Haven't read the book and don't recall the circumstance. Question though - was Zulle alone, or in a group that was trading off on pulls? If the latter, a rider sitting on the back could cause the rotations to not be as efficient, and could slightly slow the group down.

[Spreggy]

It sounds like he was there to prevent Zulle from getting off the front out of the wind. When Zulle pulls out, Kevin follows him and maintains speed. Just guessing.

[fly:yes/land:no]

I've heard the bump draft term before, what's the difference between that and just drafting?

this is how you bump draft on a bike (@ :40). exact same principle here. the first car breaks the air in front of the second car, second car pushes the first car forward physically when it catches up to it.

http://www.youtube.com/watch?v=-kZSzB4kEE8

[wanders]

this is how you bump draft on a bike (@ :40). exact same principle here. the first car breaks the air in front of the second car, second car pushes the first car forward physically when it catches up to it.

http://www.youtube.com/watch?v=-kZSzB4kEE8

Wow. 60 mph.

[waterrockets]

this is how you bump draft on a bike (@ :40). exact same principle here. the first car breaks the air in front of the second car, second car pushes the first car forward physically when it catches up to it.

http://www.youtube.com/watch?v=-kZSzB4kEE8

Perfect, that's exactly what I've been doing around here. Slower speeds though (40-50mph).

[tollhousecookie]

I tried bump drafting a minivan today.......didn't work. gotta go!!

[asgelle]

its been a few years since I read it so I'm pulling numbers out of my ass .. but it was like a 3% advantage for the lead rider.

No one has even been able to provide the data or a citation to the data to support that.

[timmyquest]

It's only a myth in that it doesn't apply to cycling...