Bassmanbob

I mentioned to a friend that during my Saturday century attempt, I did a good deed and pulled a single cyclist for 40 miles. He pointed out that my pulling also made my ride easier. Is this true? At no point did the other rider pull me.

Is it easier to pull someone than it is to ride solo? I thought that pulling a cyclist would be about the same effort as riding solo.

Any expert information would be appreciated.

Xherion

There is a small benefit to the puller as well, albeit very small.

aerodynamics - Does drafting cause resistance to the lead rider? - Bicycles Stack Exchange

bikepro

The only person who would say that "pulling" makes it easier for you has never ridden. The person in your draft is saving about 30%. You are doing all the work by breaking the wind.

OnyxTiger

So he was able to hold your wheel for 40 miles but couldn't take some pulls? Hmmm...

HTupolev

Having someone behind you reduces your turbulence. It's not a huge difference in the same way that drafting behind someone is; you'll only get up to a few percent watt savings out of it. But it is indeed something.

dksix

I would think so. I'm thinking at not only do you have to cut through the wind but the wind also has to move back into the area your body just passed through. I've ridding tight in behind semis on motorcycle and there is some pulling force in a pocket behind them. I'm thinking that the 2nd rider allows the 1st rider to escape that rearward pull of those forces. No doubt it's most beneficial to the front rider but not entirely maybe a 25/75 split. I'm just envisioning this, I may be completely wrong.

HTupolev

The claim isn't that pulling is as easy as drafting. Obviously it's nowhere close.

The claim is that pulling is easier than riding solo, which can be true. Or at least, that's what the wind tunnel says.

mcours2006

This makes sense to me too. The way a dimpled golf ball travels 2-3 times farther than a smooth one can be attributed to this very fact. The dimpled surface 'breaks up' the vacuum that forms behind the golf ball as it is travelling through the air. This low pressure behind the undimpled golf ball literally sucks the ball back, slowing it down. Though I'm sure the effect on a cyclist pulling another would be nowhere near as significant.

Vicegrip

Well said. There is an ever so Slight Reduction of drag when you have a rider right on your wheel at speed. Getting him/her to take a pull in the wind drives this number Way Up

DrIsotope

Pulling is easier than solo, self-confirmed. When I ride with my wife on the weekends, I'm usually pulling the whole time, because I ride 5x as many miles as she does, and she's not nearly big enough to make much of a draft for me. I can literally feel when she gets on my wheel-- it's like the bike gets lighter. With her within ~2 feet of my wheel, I can make about 0.5mph more speed with no increase in wattage. My average wattage for the same speed will be lower when riding with her, even though I'm pulling (i.e. 17mph solo flats vs. 17mph pulling flats.)

For a quick example:

Segment: Amazon Sprint. 0.8mi 23ft^

Solo: 3.00ET, 16.9mph, 211W
Pull: 2.58ET, 17.1mph, 200W

It's not a huge difference, but extend it out over a couple of hours.

Bassmanbob

Interesting. This makes sense. I did some reading on ballistics when helping my daughter with her science fair project, using model rockets. I vaguely remember reading about some basic concepts concerning the turbulent vacuum behind the rocket, hence why the rear of the engine was to be placed about a 1/4" behind the end of the rocket's body. It helped funnel the air back into that vacuum with less turbulence.

Sometimes I wish I had studied more physics in school.

andr0id

I'm going to guess that's based on the position of skilled cyclists riding tight on a wheel (6 -18") and not typical recreational drafting that is often a Charlie Foxtrot to start with.

bbattle

It's the reason NASCAR drivers "push" each other. But the benefit at their speeds is much greater than at what cyclists are capable of, obviously.

Anybody that says they helped you by drafting off you for 40 miles is pulling your lariat.

dksix

That's the principle behind a boat tail bullet. There is also a correlation between bullet length vs diameter, something about making the bullet longer and tapering the tail allows it to be heavier without increasing frontal area (heavier maintains energy longer, bucks the wind better and the boat tail actually lower to coefficient of drag. I used to know a lot more about that but it left pretty quickly when I stopped shooting seriously.

smarkinson

This has been studied in the past:

Drafting Aerodynamics | CyclingTips

The relevant information from the above article:

This was measured in the General Motors Wind Tunnel in 1996, and on the track using the SRM crank dynamometers. The lead rider in a 4-man pace line uses about 2 to 3 percent less energy than they would if riding solo.The next in line needs about 71 percent of the lead rider’s power, and the third and fourth riders about 65 percent. See “Racing cyclist power requirements in the 4000-m individual and team pursuits”, Medicine and Science in Sports and Exercise, v31, no.11, pp 1677-1685, 1999. J.P. Broker, C.R. Kyle and E.R. Burke.

So, in a 4 man pursuit team, travelling at about 40mph in very tight formation (inches behind the guy in front) the lead reader uses 2 to 3 percent less energy. At less than 20mph on the open road with crosswinds and the guy behind you sitting maybe a foot or two of your back wheel I think you'd be lucky to be getting a 1 percent advantage.

mpath

Indeed you did a good deed. I wouldn't have been so gracious.

rpenmanparker 

What makes the advantage for the puller hard to observe is that they are pulling way harder than they would normally ride solo, enough so that the pullee feels like they are riding solo at their normal cruising speed. That extra effort by the puller hides the small advantage of pulling.

bruce19

I can't get too upset about someone sitting on my wheel. If they're not there I'm going to be riding anyway.

Dan333SP

They don't have to pull harder than they'd normally ride solo, unless they're trying to impress the rider behind with their massive guads and dial it up to 400w.

WhyFi

Wut. On some of my routes that head in towards the city, I'm happy to pull a commuter if they end up on my wheel, but I sure as hell ain't stepping up the pace for them.

velociraptor

Did I miss the part where the OP peeled off and gave the other guy an opportunity to pull for a while?

I mean, if I'm on someone's wheel for a while and they just keep going and going, I'm not gonna try to overtake him just for the fun of it.

Although, I might yell something about taking a turn... but maybe not(?) For all I know, he might be enjoying his sufferfest.

Bassmanbob

That's what was going through my mind.

Bassmanbob

There were a few times I said I was getting fatigued and moved over. He didn't get the hint, so I let it go.

gregf83 

If you're in a group most people will pull harder than if they were riding on their own at a steady pace. Otherwise, you wouldn't get much of a workout.

Dan333SP

Right, if you're rotating in a group. If some rando is sitting on your wheel doing no work for 40 miles like OP, there's no incentive to ride harder than he would if he were solo other than the tiny draft benefit we've mentioned.