Can You “Push” the Lead Rider?

Cycling Science: Paceline Physics: Can You “Push” the Lead Rider?

Question:
We all know that drafting reduces the effort for the person in back. Given the laws of energy conservation, is there an opposite effect for the person in front? Does having someone draft off you make you work harder? Or does it actually give you push? I found this article about auto racing that discusses drafting and makes the point: In car drafting, the lead car is also getting a benefit. Trailing cars fill in the lead car's low-pressure wake, thereby cutting down pressure drag. -- Bill Rosenfeld

Bob Howland Replies:
Briefly, at the back of a race car there is turbulent air, in a low-pressure system created from the Bernoulli Effect as air sweeps up over the top of the car and down its rear area – think, aircraft wing. But another air mass flows under the car, passing between chassis and road surface. The different air masses rejoin at the back of the car and swirl, which essentially creates trailing drag.

If a second car pushes its pressure cone into this swirling air, it smoothes out the swirl, thus reducing trailing drag. So the "push" of the second car is a result of the second car forcing that swirling air to continue on under the second car, and over the second car. Two cars working in conjunction act as a single, longer entity. There is only swirling air, or trailing drag, behind the second car. They both supposedly can go faster than a single car. But the second car has it easier, drafting in the low pressure of the first car.

So, what about bicycling?
Well, I have watched many lead-out trains with 5-6 riders. There is NO question to me that an organized lead-out train can go much faster than a single rider trying to get by them. One lead-out train really is never challenged -- unless by another lead-out train acting as a single entity. So, at the approximately 35-40 mph elite racers can do, I am led to believe the drafting-pull effect is there.

Yes, they are going slower than a 200-mph race car, but the cyclists have a much smaller frontal surface area, so my guess would be the effect is there, just proportionally scaled down.

We all know you can feel the draft when you’re behind another rider. But, realistically, is there a "push" that can be felt by the lead car or the lead cyclist? For cars, maybe. I am speculating. For cyclists, I'd say the effect is there, but small enough not to be felt -- unless maybe by those elite racers riding at 35 mph in team time trials or lead-out trains.

Five old guys cooking at 25 mph is fun, and I bet the effect is there, but so negligible as not to be felt.

I'd have to say, I know it when someone comes up silently behind me if I am cruising at around 20 mph because somehow the airflow feels different than riding alone. But I would NOT describe it as a push. I would also say, when you ride deep within a peloton, the air flow feels different than when you are at the very back of the group.

uhurm !! Can't comment much on this article since I don' t really pull pero alam ko dyan kung sino ang pumatay sa "dyey ar" peloton sa keppel last sunday heheheh.

BlindRunner wrote:uhurm !! Can't comment much on this article since I don' t really pull pero alam ko dyan kung sino ang pumatay sa JR peloton sa keppel last sunday heheheh.

ikaw ang pumatay sa JR riders walang iba.... at may isang JR rider na parang c Boasson Hagen yong malapit ng bumaba.

Ang lulufet!
Usapang malulufet to! Mga astig!

Me, im always a passenger, seating on the passenger seat! Manong bayad po!
Subukan nyong sumama ke fafi Ryan... Wala kayong ibang view kundi pwet nya!

Try nyo. Hehehe

BlindRunner wrote:uhurm !! Can't comment much on this article since I don' t really pull pero alam ko dyan kung sino ang pumatay sa JR peloton sa keppel last sunday heheheh.

Sa JR ride last Sunday sa Tuas, nahati ang grupo dahil sa stop light. Medyo malayo
na ang gap pero buti na lang may nag-trangko para maabutan yung unang grupo.
45kmh ++ ang speed nung pinoy na nag-pull ng 2nd group hanggang dumikit
na sa 1st group. Mahaba-haba rin yun. Ang tindi!!!!!! Ang napasin ko lang ay yung
bike ng pinoy. "Puting Giant". At sabi niya hindi raw siya nag-pu-pull.

GIANT wrote:Ang lulufet!
Usapang malulufet to! Mga astig!

Me, im always a passenger, seating on the passenger seat! Manong bayad po!
Subukan nyong sumama ke fafi Ryan... Wala kayong ibang view kundi pwet nya!

Try nyo. Hehehe

Tried alot of times already...hehehe

Pero napansin mo ba na yung pwet ni fafi Ryan ay parang pwet ng bebot?

Sa totoo lang pre... Pag kasama si Ryan sa ride e ni
anino nya di ko nakikita , maliban pag weekday ride hehe.
Naku try nyo ngaun, naka race pace yun.

Pero mukang ako eh natatakot na din sumama sa inyo. Ang lulufet!

Ganun? mukhang balak na talaga ni fafi ryan makatungtong sa stage.


Basta naduon ako, huwag kang matakot dre. Sila lang yung malulufet.
Ako, pogi lang. hehehe

Proud2bpinoy wrote:Ganun? mukhang balak na talaga ni fafi ryan makatungtong sa stage.


Basta naduon ako, huwag kang matakot dre. Sila lang yung malulufet.
Ako, pogi lang. hehehe

lupit mo talaga white bomba!!!

GIANT wrote:Sa totoo lang pre... Pag kasama si Ryan sa ride e ni
anino nya di ko nakikita , maliban pag weekday ride hehe.
Naku try nyo ngaun, naka race pace yun.

Pero mukang ako eh natatakot na din sumama sa inyo. Ang lulufet!

Tama ka nga Giant. Nag-RTI kami kahapon nila blindrunner, makoy, ernest at rio.
Nilagpasan kami ng grupo nila fafi ryan. Hindi ko nakita kahit anino ni mr edit sa bilis.
Grabe yung pace nila. Race Pace talaga.