Effects of draft in large group
09-25-18, 06:36 PM
#26
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See the study at https://www.sciencedirect.com/scienc...67610518303751. Its a simulation of a large peloton. It shows the lead rider experiences about 85% the drag compared to an individual rider. Farther back in the peloton, many riders experience less than 10% of the drag. So really significant drag reduction.
Mark
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09-25-18, 08:49 PM
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See the study at https://www.sciencedirect.com/scienc...67610518303751. Its a simulation of a large peloton. It shows the lead rider experiences about 85% the drag compared to an individual rider. Farther back in the peloton, many riders experience less than 10% of the drag. So really significant drag reduction.
Mark
Mark
09-25-18, 09:46 PM
#28
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https://www.sciencedirect.com/scienc...67610518303751
I've seen studies before which shows that in a 4 man track team time trial the lead rider gets a 3% reduction in drag due to the following riders .
" It was found that the trailing cyclist can provide a drag reduction of almost 3% to the leading cyclist due to the upstream effect exerted by the trailing rider on the flow. This effect was later confirmed by Defraeye et al. (2014) and Barry et al. (2015) who studied the aerodynamic drag of four in-line cyclists for a team pursuit. ".
The above study indicates that a lead rider on a pack of 121 riders can have aero drag that is up to 86% the level of a single rider.
"Unsurprisingly, the largest drag in the peloton is experienced by the leading rider, who however experiences a reduction in drag down to a value of 86% that of the isolated cyclist riding at the same speed. The cyclists at the outer front edges of the peloton leading rider excluded have a drag reduction down to a value in the range of 5967% that of the isolated rider. For riders sufficiently embedded inside the peloton, the aerodynamic drag rapidly decreases. The riders near the center of the four last rows have the lowest drag. Their resulting drag can go down to only 5% of that of the isolated rider. Overall, the cyclists at the mid rear of the peloton have the strongest drag reductions. 57 of these riders have drag reductions down to 510% that of the isolated rider. This means that almost half of this peloton travels at very low cost in terms of energy. "
09-26-18, 06:58 AM
#29
wears long socks
Apparently yes they do.
https://www.sciencedirect.com/scienc...67610518303751
I've seen studies before which shows that in a 4 man track team time trial the lead rider gets a 3% reduction in drag due to the following riders .
" It was found that the trailing cyclist can provide a drag reduction of almost 3% to the leading cyclist due to the upstream effect exerted by the trailing rider on the flow. This effect was later confirmed by Defraeye et al. (2014) and Barry et al. (2015) who studied the aerodynamic drag of four in-line cyclists for a team pursuit. ".
The above study indicates that a lead rider on a pack of 121 riders can have aero drag that is up to 86% the level of a single rider.
"Unsurprisingly, the largest drag in the peloton is experienced by the leading rider, who however experiences a reduction in drag down to a value of 86% that of the isolated cyclist riding at the same speed. The cyclists at the outer front edges of the peloton leading rider excluded have a drag reduction down to a value in the range of 5967% that of the isolated rider. For riders sufficiently embedded inside the peloton, the aerodynamic drag rapidly decreases. The riders near the center of the four last rows have the lowest drag. Their resulting drag can go down to only 5% of that of the isolated rider. Overall, the cyclists at the mid rear of the peloton have the strongest drag reductions. 57 of these riders have drag reductions down to 510% that of the isolated rider. This means that almost half of this peloton travels at very low cost in terms of energy. "
https://www.sciencedirect.com/scienc...67610518303751
I've seen studies before which shows that in a 4 man track team time trial the lead rider gets a 3% reduction in drag due to the following riders .
" It was found that the trailing cyclist can provide a drag reduction of almost 3% to the leading cyclist due to the upstream effect exerted by the trailing rider on the flow. This effect was later confirmed by Defraeye et al. (2014) and Barry et al. (2015) who studied the aerodynamic drag of four in-line cyclists for a team pursuit. ".
The above study indicates that a lead rider on a pack of 121 riders can have aero drag that is up to 86% the level of a single rider.
"Unsurprisingly, the largest drag in the peloton is experienced by the leading rider, who however experiences a reduction in drag down to a value of 86% that of the isolated cyclist riding at the same speed. The cyclists at the outer front edges of the peloton leading rider excluded have a drag reduction down to a value in the range of 5967% that of the isolated rider. For riders sufficiently embedded inside the peloton, the aerodynamic drag rapidly decreases. The riders near the center of the four last rows have the lowest drag. Their resulting drag can go down to only 5% of that of the isolated rider. Overall, the cyclists at the mid rear of the peloton have the strongest drag reductions. 57 of these riders have drag reductions down to 510% that of the isolated rider. This means that almost half of this peloton travels at very low cost in terms of energy. "
I'm 6'4" tall and 185 pounds. The best draft I've ever felt was in a large group where I easily maintained 22mph with 140w of power. To average 22mph on my own, I'd need to push close to 250w.
In a large group where the lead rider rotates off to the back and recovers, I would estimate that a typical recreational cyclist could net 4-5mph.
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