I saw this online and wondered how accurate this is. Anyone?
Probably pretty accurate. I remember Liggett saying on one of the race broadcasts I was watching “You save 40% when you’re tucked in behind your mates”.
And I know Phinney (the elder) used to chase semi’s down the mountain roads in colorado tucked into their draft, at 60+mph.
John
The single file stuff I think would vary a lot based on how windy it is, and what angle the wind is coming at.
I’m surprised by the claim that 5th in line is no better than 3rd or 2nd in line. I wonder if that is usually true.
The single file stuff I think would vary a lot based on how windy it is, and what angle the wind is coming at.
I’m surprised by the claim that 5th in line is no better than 3rd or 2nd in line. I wonder if that is usually true.
http://www.ncbi.nlm.nih.gov/pubmed/10589873
Probably pretty accurate. I remember Liggett saying on one of the race broadcasts I was watching “You save 40% when you’re tucked in behind your mates”.
And I know Phinney (the elder) used to chase semi’s down the mountain roads in colorado tucked into their draft, at 60+mph.
John
I have two sets of power data that show ~30% savings. Single event, relatively sheltered road with large trees on both sides. Two riders, same height, same frame size. 2nd rider moved in and out of lead rider’s draft during lead riders threshold interval. The difference from directly behind to a 7:30-8:00 position was about a 30% power increase. Not a highly controlled study, but rather just a datum.
How much benefit do you lose if you keep having to check over your shoulder for draft marshalls?
Probably pretty accurate. I remember Liggett saying on one of the race broadcasts I was watching “You save 40% when you’re tucked in behind your mates”.
And I know Phinney (the elder) used to chase semi’s down the mountain roads in colorado tucked into their draft, at 60+mph.
John
I have two sets of power data that show ~30% savings. Single event, relatively sheltered road with large trees on both sides. Two riders, same height, same frame size. 2nd rider moved in and out of lead rider’s draft during lead riders threshold interval. The difference from directly behind to a 7:30-8:00 position was about a 30% power increase. Not a highly controlled study, but rather just a datum.
I saw something similar on a century ride that with myself and another rider. Into a 20 MPH headwind, I had to push 260W to average the speed we were going…can’t remember how fast…not very…but, when I was in his draft, I was yawning at 180W…
A little bird referred me to this http://www.ncbi.nlm.nih.gov/pubmed/2318782 It’s the source of the data in the pictogram.
I saw this online and wondered how accurate this is. Anyone?
So if you are on a 5% hill going at 15mph, the power to overcome aero drag is ~65W. Does this mean you can save about 15W by drafting (assuming no wind, etc)?
That last diagram shows and old UPS 6 cube…so don’t be expecting to hit 60…now if it was a new 12 cube or Sprinters and they are heading out to their route or back to the barn…jump on, otherwise go it alone, too many stops.
I used to chase city buses back into town on my morning rides. My group would generally ride about 35kph on the 10km dead flat, nicely paved road to town. One time, I jumped on the back of the bus (gotta know where bus stops are, and gotta keep to the centre of the road side of the bus so when they slow down to pull over, you don’t rear end the bus) and got a flier of a ride to town. Most of the time we were going 65kph, and I was braking half the time.
I found that at that speed, the wind coming off the bus and curling around, meant that with my front wheel about 10 feet behind the bus, I was actually being pushed forward and had to brake quite a lot. With my front wheel say 2 feet off the buses bumper, I was in still air, and actually had to ride quite hard to maintain 65kph. 10 feet gives you more room when the bus pulls over.
I’ve also drafted of a transport truck and 75kph on the flat. He had one of those spray diverter things at the back so I got a really good tow.
Drafting off vehicles can be good fun and not nearly as dangerous if you choose the right vehicle and location to do it.
Drafting off fellow cyclists is an advantage, but never as much as you want at the time 
Unless for people who draft off a fat tridork that is!
That’s really cool. I’m trying to figure out how to do our virtual aerodynamics for courses. The link from the study should help too.
If you have any more scientific info (less pics, more data) send it my way please :).
The single file stuff I think would vary a lot based on how windy it is, and what angle the wind is coming at.
I’m surprised by the claim that 5th in line is no better than 3rd or 2nd in line. I wonder if that is usually true.
It is true for single file riding
In a peloton, it’s better
I saw this online and wondered how accurate this is. Anyone?
Regarding that last one especially, what’s more interesting, is if the bike is well in front of the truck, the bike rider still gets an aero advantage (although not by as much).
my unscientific but field-based evidence: about a month ago, I entered a road race. It was a windy day, and I was riding in the front group, when at the turnaround point I was caught napping and they dropped me. They were about 100m ahead of me when I started chasing them. It took 5 mins at 390 watts to catch them. Once I’d caught them I continued at the speed of the group, and I was doing 145 watts.
Obviously I was riding slightly faster to catch them (25 mph) than the group was riding (23 mph). But even 300 watts alone vs 150 watts in the group is a pretty big saving
That’s really cool. I’m trying to figure out how to do our virtual aerodynamics for courses. The link from the study should help too.
If you have any more scientific info (less pics, more data) send it my way please :).
Seriously? Holy crap Nate. I’ll let you know if I find anything.
Yah. We talked to one “scientific” group that was going to help us, but they charged too much money. Their calculations were a little too heavy too. Almost like running a CFD app inside of TrainerRoad.
We want something simple that makes online racing fun. It doesn’t have to mimic outdoors 100%, but it should be pretty close.
Any help would be appreciated!
I assume you know about analyticcycling.com?
Yes. The those physics aren’t too hard to code to.
The missing link for me is how much of a reduction in drag should I assign someone riding with different riders. For example 2 riders, 5 riders, pack of 30, ect.
I don’t think we’re going to throw in wind (other than rider generated) in the first go around. But that would be cool to add too.
I saw this online and wondered how accurate this is. Anyone?
Regarding that last one especially, what’s more interesting, is if the bike is well in front of the truck, the bike rider still gets an aero advantage (although not by as much).
Plus, the rider gets the ‘Oh shit, I’m gonna get run over by an old, boxed UPS truck’ adrenaline rush which is good for a couple of extra mph/ kph.