Bicycle Drafting

[talindsay]

So I've been cycling as my main (cross) training activity this week, and I have to ask the bicyclists on this forum: what's up with drafting? Trying to simulate my runs as close as I can, I'm riding along trying to maintain a steady elevated heart rate, which means I'm going 18-20 mph depending on terrain. For a real cyclist that would be slow. For a commuter that seems pretty fast. So why do all these people keep drafting off me? It strikes me as incredibly rude - I'm trying to keep a steady workout going, I don't need somebody sapping my energy. But I also can't see why they're doing it - it's not like we're out on a 50-mile ride in a group, where drafting makes sense. If they're out for exercise, don't they actually want to exercise? And if they're commuters who are capable of maintaining my speed, why are they drafting off me? Is it just an accepted thing in bicycle culture? Do all cyclists "in the know" understand that this is the cool thing to do or something?

[MNdible]

It strikes me as incredibly rude - I'm trying to keep a steady workout going, I don't need somebody sapping my energy.

They're not sapping any energy from you. You actually likely gain a slight aerodynamic benefit by having somebody drafting behind you. Obviously not as much as they gain, though.

[bubzki2]

There are a lot of people out there who spend a lot of money to buy very fast, light, shiny bikes -- in order to get exercise.

I don't get it, either.

[David Greene]

There are a lot of people out there who spend a lot of money to buy very fast, light, shiny bikes -- in order to get exercise.

I don't get it, either.

In this case I think it makes sense if you want to travel farther/longer. In my case, my legs generally burn out faster than my cardiopulmonary does so having a lighter bike lets me ride further and longer for the same amount of effort. I can pump weights at the gym if I want to work on leg strength. I don't have a super-fancy bike at all, just a reasonably nice road bike. It's also nice if I'm not out for exercising but actually want to go somewhere some distance away. A lighter bike makes a huge difference.

[bubzki2]

Yes, but a skilled cyclist can cover 15 miles per hour on a junky mountain bike with decent tires. It's diminishing returns, and I would argue bike weight doesn't make a significant difference in most cases.

[talindsay]

It strikes me as incredibly rude - I'm trying to keep a steady workout going, I don't need somebody sapping my energy.

They're not sapping any energy from you. You actually likely gain a slight aerodynamic benefit by having somebody drafting behind you. Obviously not as much as they gain, though.

This author appears to agree with you: http://www.exploratorium.edu/cycling/aerodynamics2.html. I've always understood it to be more work when being drafted. I certainly experience it that way, though perhaps because I'm constantly paranoid about some dude I don't know being right against my wheel. The distraction may just make me perceive it as more work, I suppose.

[talindsay]

By the way, this wasn't a rant - it was a question: in bicycle culture is it considered acceptable to draft off strangers in a non-race setting?

[MNdible]

That's factually incorrect. The person drafting gains a bigger boost than the person being drafted loses, but the person being drafted does have to work harder.

I don't have a degree in thermodynamics, but there are about a million internet references I could link to that support this claim.

Here's one:

We measured this 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.

Read more at http://velonews.competitor.com/2002/12/ ... SjpIMDH.99

[talindsay]

Yeah, I just updated my above comment since it appears you're correct.

[talindsay]

There are a lot of people out there who spend a lot of money to buy very fast, light, shiny bikes -- in order to get exercise.

I don't get it, either.

Haha yes, I have a former boss who has spent a lot of money on über-nice bikes so he can go on rides with friends and stay in shape. Nothing wrong with that of course, but anything that makes it easier does rather detract from the fitness benefit. It takes me a lot of concentration to keep my heart rate elevated on a bike anyway - as soon as I start to lose focus the heart rate drops.

[VAStationDude]

For me going more than twenty minutes on a cheap mountain bike is really uncomfortable. A nice bike with a quality component group (Shimano Ultegra) can be had for a couple grand, which, if you ride a lot, isn't too expensive since you're spreading the cost over fifteen thousand-twenty thousand miles.

[grant1simons2]

I have guys who come into the shop with really cheap frames from old bikes, like a 80s fuji which would go for $200 at times. And have some of the best quality components. Really I think you don't need a new bike. As long as you have a frame that feels good for you and newish components you're fine. I ride fast for a long time on a Schwinn World Sport

[tab]

I appreciate the chance to draft, and don't mind if someone drafts behind me. I do wish there was a more formal culture though around checking for permission. I try to ask if it's o.k., but sometimes if there's someone in full spandex on a racing bike, I assume they won't mind, but maybe that's too much to assume. Just last week someone drafted behind me for a mile or two, and then overtook me and I drafted behind him for a mile or two. It's only fair to try to take your turn as the lead rider, so the other bicyclist gets a bit of a break. It's nice on a long commute because you can cover more miles with less energy, leaving yourself a bit fresher for the balance of the commute after you and the other bicyclist part ways. It's something really nice about biking, that a headwind (or just the typical air resistance) is cut down considerably when you're riding close to others. There's no equivalent for that when driving, at least not on a typical commute.