I had absolutely no idea that there was a positive draft effect almost 40 feet behind an "aero" rider in front of you. This is correct??

How do you know it's exactly 12 meters?
The practical application of your scenario for keeping it "legal" would be that you're constantly overtaking each other - not that you're in a fixed order at exactly 12 meters from each other.
Otherwise there's a high chance that you'll end up in someone's draft multiple times and then slotting back (which is a drafting violation) but you would only be caught if a referee was passing at the right time.

The other legal way to do it is how the pros do it, you sit at something substantially over 12 to avoid risking a drafting penalty.

By the way, referees don't have a way to measure 12 meters so if it looks like you're drafting and there's a referee, you might get a penalty even if it's more than 12.

Keep in mind that if you hit an incline or accidentally get too close to the person in front of you, if you're suddenly in the drafting zone you should pass the entire paceline.

And if you're being passed, you need to slot back until you reach the end of the paceline.

This is CFD (simulation, not real world numbers) and about the pro cycling peloton, but the saving in the middle are huge, so even in smaller groups with more spacing there are gains. Here's some real world numbers from 2013 (found it on ST).

Oh yeah it’s correct, why else would PROs ride in pacelines, talk about “getting dropped”, etc,?

My take on the OP: absolutely, if I could do it, I would feel zero guilt. Unfortunately I don’t swim well enough to usually catch the people I could bike with. It’s a rare feat for me not to be in the wind almost all the race.

One reason not to legally draft 12 m behind someone is to hold your power. Sometimes I race others, sometimes I race myself. When I race myself, I might be looking to do a best ever power on the bike and follow it with the fastest run, for example. This is because of the way bike courses make comparisons of bike splits difficult.


The practical application is that you hold 13 meters (5 bike lengths from the rear wheel plus some margin). The draft effect doesn’t suddenly drop or disappear over that meter.

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"FTP is a bit 2015, don't you think?" - Gustav Iden

Yes but:
- referees don't have a laser meter. Your judgement of the space may differ from that of a judge on a motorbike. And there's no way to appeal that
- you have to consider that if you accidentally enter the drafting zone you have to pass the entire paceline. And if you're being passed you need to slot back to the end of the paceline.
In the real world hardly any amateur does it and that's how the massive draft packs are formed. Most don't even know the rules well enough to tell the difference or simply know they are likely to get away with it.

The real world application of amateurs staying in a paceline is that most are drafting a lot of the time.

Feel good about it if you're doing it right, feel bad about it if you aren't 🤷

Nope: not an scintilla of guilt.
J-P Ballard offers an insight:
13% at 45kph (lead rider in TT position, @ 12m, so 10m between)
@30:05 and graph @30:56 for the impatient ones.
https://youtu.be/lmqdqcOvrlc?t=1805
Also excellent graphic quoted (drawn from Blocken's work at Eindhoven):
https://twitter.com/...860543340544/photo/1
Moto 40m ahead gets you a 10% power saving (@?50kph - Ditlev flat speed)
Moto 3m behind (only) gets you 0.3%.

well on the one hand, if its legal then why not.
on the other hand, drafting (legal or not) is a blight on the sport and corrupts the integrity of the race. many here argue for a 20m draft zone so why not walk what you talk?
also consider that the tension of keeping it legal but effective with the variations in pace may actually be more taxing than just doing the work yourself

Why would anyone be compromising the integrity of the race when keeping the legal distance? Are you saying that all pros are compromising the integrity of the race by legally drafting? (yes, that includes the likes of Sanders, Skipper and Long whenever they are working together and with other riders to limit their time losses on the bike to the faster riders at the front)

My experience as spectator: at any IM event, the middle of the packs folks (5:30- 7 hour bikers), will always be around hundreds of riders. Most of these folks are very often 1-2 m from other riders on many occasions. Just watch any full distance bike ride gopro video on YT by middle of the pack folks. IM races simply don't have enough resources to police these guys nor enough space to spread everyone apart.

And all of them will claim that everyone around them was drafting big time but they were always 12 m from the other riders. Not saying that all MOP are cheating, simply saying that it would be impossible to line up 1,000 riders over 20 km worth of highway and keep it that way.

If you are racing for AG podium and at the front of the race, legally drafting is important to save as much energy as possible. And this is also where the refs will be paying a bit more attention.

Problem is that if you leave 20m then others will pass and, perfectly 'legally', cut in, and you have to feather the brakes (or at least sit up), and someone else will come past (probably because you have slowed) and repeat.
Agree last point.

"- you have to consider that if you accidentally enter the drafting zone you have to pass the entire paceline. And if you're being passed you need to slot back to the end of the paceline."

Actually, as an age grouper, in Ironman racing, you do not need to pass the entire paceline / group if you enter the draft zone. You are allowed to slot in, ride through the draft zone, then pass the next rider, and so on if you choose. (Or slot in at 12 meters and stay of course) If you are being passed you simply need to show you are letting the gap open back to 6 bike lengths (and do so in 25 seconds)

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Dave Latourette
http://www.TTENation.com

What interpertation of the rulebook are you getting that from, curious?

If you "slot in" you are then in the draft zone of the next person and must pass. Where is "slotting in" allowed for AG'ers but not for pros?

Or maybe I'm misreading what your saying....you can slot in and draft the athlete ahead of you as long as you still pass said athlete within 25s? I'm not sure you are allowed to enter the draft zone when you "slot in" and then not make the pass.

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Brooks Doughtie, M.S.
Exercise Physiology
-USAT Level II

To the OP don't feel guilty. That's what you should be looking for. Just make sure move to the front and don't slot in or back out of the draft zone. In my experience, 70.3 racers slot in all the time, pushing you further and further back if you don't what your supposed to, or that forces you to move to the front.

Here's my question, if someone slots in on you, you're supposed to back out of their zone because you've been passed. But they broke the rules and now you have to drop way back from the front of the pack if this is a train. And now that you've back, someone else will slot in, and you're losing time as you keep backing out. So how does everyone feel about the proper etiquette being if someone clearly slots in, say a 5 person group, you immediate pass the entire group and move to the front. I realize if seen the official might call a penalty (should call a slotting one) but I've never seen that in an AG race, so are you really going to get dinged for the immediate pass?



Hot take, the 12m draft zone works and the benefit is not all its talked up to be. Sam Laidlow doesn't get caught by the pack at Ironman and Taylor Knibb doesn't get caught at 70.3 (or 20m PTO). I submit that when the stars and planets align for a brief moment you get a noticeable benefit, but those moments aren't enduring over the hours they are in a pack together and the real benefit is the fact that you're fighting to stay in a group and pacing yourself with them. We don't see groups catch Taylor or Sam who should be massively fatigued compared to everyone else.

The pack pulled away from Lionel in St George 2022 and still didn't catch Laidlow there either. Lionel bikes mostly on his own and out runs the pack. So I suggest at the pro level that a properly spaced pack that's not a euro-level cheat pack, really just helps the bulk of the racers pace their way to the front and sometimes they over pace or get it just right and catch the leader in time.

Hey Brooks, hope you are well.

There is no interpretation, the referees (and competitive rules) will confer that this is not only legal BUT some refs will encourage (if safe) to pass by "slotting in", slipstream, pass, and so on. (FOR AGE GROUPERS ONLY) ... and as you referenced correctly, YES you can slot in, slipstream, and pass as long as it is done in 25sec. Rules will say you have 25sec to pass through the draft zone.

My copy of the rule (from my copy of Ironman's Competitive Rules) is below. This is a detailed version that may have more verbage than Ironman's Athlete Guides. It also clearly differentiates between the Pro and AG rule.

(a) “Drafting” means to remain within the draft zone (as described below) of another athlete for a period longer than 25 seconds. Drafting during the Race is prohibited; (5:00 Minute Time Penalty) (b) The bicycle draft zone is 12 meters long, measured from the leading edge of the front wheel and extending towards the back of the bike (6 bike lengths of clear space between bikes). Athletes may enter the draft zone of another athlete when passing and must continuously progress through the draft zone. A maximum of 25 seconds will be allowed to pass through the zone of another athlete; (5:00 Minute Time Penalty)
**(i) Prior to entering the draft zone of another athlete, professional athletes must move to the side of the athlete being overtaken (i.e., no slipstreaming). Failure to do so will result in a drafting violation; (5:00 Minute Time Penalty)


For clarity I am an announcer at number of Ironman events and I have to address this at our race briefings. I do my best to make it clear for the athletes.

Coincidingly, I encourage the athletes that I coach and advise, to function within the rules when passing to limit their power spikes and stay smooth.

Feel free to reach out if you'd like.

Cheers,
DL

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Dave Latourette
http://www.TTENation.com

I just want to confirm one point. You previous stated you could slot in and NOT be forced to pass (see the bolded point). That isn't correct is it? If you "slot in" and suddenly in the draft zone of the person ahead of you, as an AG athlete you would have to pass, yes? We may be mixing up terminology, because I've always referenced "slotting in" as passing one yet by passing the person you are now in the next person's draft zone. I would think if you are passing a line of riders that are at 12m, you technically wouldn't be able to stay in that slot because you would have been 11.99 and thus in the draft of the next guy. Obviously if everyone is 15m and you pass, you can "slot in"; but for the purposes of most people, that's not what we reference as "slotting in".

(Or slot in at 12 meters and stay of course)




(I'm going on the assumption that if 3 guys are 12m apart, when you pass 1 rider you are now inside 12m to the next guy, so while yes you are to slot back in to the right, you then must pass the next rider...obviously if they are 14m and you pass yes you can sit at 12m after slotting in with no issue.....but if riders are all exactly 12m, apart, you then are in the draft zone of the next athlete the moment you pass the 1st rider.....you can't say you are at the 12m zone *technically*)

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Brooks Doughtie, M.S.
Exercise Physiology
-USAT Level II

In the age group race, you may "slot in" at <12 meters, slipstream, pass in 25sec or less, and continue.

Re your clarifying point ... if you move in / slot in between two riders, and you are less than 12 meters to rider in front, yes you MUST pass. As the officials will say, "there is only one way to exit the draft zone, and that is forward"

Hope that makes my mumbo jumbo more clear ;-)

DL

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Dave Latourette
http://www.TTENation.com

10-4 we are on the same page there.

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Brooks Doughtie, M.S.
Exercise Physiology
-USAT Level II

Sorry to derail this a little, but I'd love some clarification from your expertise about what I thought was a "slotting in" violation. In a race earlier this year, I was 3rd in a line of 4 holding 12+m apart for a good several minutes on a long flat/gently rolling section if an IM.

An athlete came up beside me, and then started leaning/steering their bike toward me, pushing me towards the gravel shoulder. I yelled at them to watch out & hold their line and they started screaming that I needed to sit up/brake/drop back because I'd been passed.


It's stuck with me — was I incorrect? Did I need to actively brake or make rearward progress or was I right hold my 12m+ spacing as the other athlete worked to pass us all?

I have to admit, it is in the rules in terms of the draft zone and therefore I don't feel particularly guilty if I am doing what is legal as per the rules (and I know if I am doing it legally then there are like lots more doing it both legally as well as a number who will be doing things illegally).
As a comparatively stronger biker but whose wave starts always tends to be towards the end of the wave starts, I have also found there is a reasonable amount of legal (if not potentially slightly unfair) advantage that you can gain from slingshotting past other riders. By that I mean legally entering the draft zone, utilising that draft to help accelerate, pass and then carry on through the field as you can like that.
I have not, fortunately, raced in events that are a massive draft fest because of the number of entrants versus the bike loop size etc. I look at those races and groups and see the power that some people are putting out and have always wondered what I would do if I ever found myself in that situation-try and smash off the front and just drag the group along or try and be legal and sit up and drop back, only to find another massive group comes along. I can see how some people just say screw it and get "stuck" in a massive bunch, especially when the TO's don't do anything about it.

This is where it gets kinda dumb with the age group rules.

Unless you are sitting EXACTLY 12m (or whatever the distance for your race's rules), the other person was technically right. If you are 12.5m back, and their front wheel passes your front wheel by 0.1m, then they can sit there at 12.4m back of the next person's n and you must drop back out of their draft zone.

If you are sitting 11.9m back, they can't do this and would have to start passing the next person. However, then you'd be drafting the person in front and in the wrong.

You can see why there are different rules for the pros at least because this situation becomes impossible to officiate with the naked eye.

Thanks for the clarification.

I don't think you should feel guilty about riding within the legal draft zone. Obviously you're still getting a benefit but hopefully you're taking turns at the front + a lot of riders break the rule & draft as much as they can on the bike. I make sure to ride according to the rules. When you're competing for places up front, it's almost frustrating to follow the rules if you miss out on one or two spots & dk how others approached the bike. Just need rules to be enforced more. Maybe it should be 20 instead of 12 for everyone but no need to feel a type of way about following what it is now.

You're looking at it the wrong way IMO. Drafting in a race isn't a legal or moral or ethical issue. It's a risk/reward competition question. If you get an infraction you don't go to jail, you don't get suspended, you get an in-race penalty.

We know the risk, a 5 minute penalty. Which is effectively ~4min since you get to rest. We know the reward. If you can hang onto the back of a group at ~12m for an IM it's much more that 5 minutes.

If (chance of getting penalty)*(penalty time) < (time gained by pushing limits of draft zone) - (time saved by taking 'no risk' draft zones) then it makes sense to push the limits.

Look at NCAA football. The penalty for defensive pass interference is 15yds. If a defender is beaten for a 20+yd pass you often see them just blindly swat at the receiver. Makes sense, accept the 15yd penalty in lieu of a 20+yd completion.

Nothing wrong with sitting the legal draft distance behind another rider. We may be Age Groupers but we are allowed to ride tactically to try to get our best result still!

The only time I question about it is when fields overlap; e.g. at Swansea 70.3 I was catching the womens pro field from the AG waves... and ended up in a group of a relay team, 40-45 AG, myself (18-24 AG) and a female pro. Admittedly it is a hilly enough/twisty enough course (lanes on the gower... so not just a dead straight max advantage being tucked in road), but I still was unsure should I be riding with this group when we were all in the vicinity given that simply by our presence without the female pro purposely dropping like 20+m back to get out of the draft realistically we were interfering in the womens pro race.

It wasn't on purpose, (and I also want to stress the female pro was in no way purposely surging with our group to use our draft as we gapped on the courses main climb), but it felt like potentially by being part of this legal draft group we were interfering in another race as such. I don't really know how to avoid this situation, or what I was supposed to do in it. I just raced my own race as I planned to and the group splintered through the ride as we went through the more technical bits.

Never quite got my head round what to do in the situation tho, as I wanted to go as quick as I could (fighting for o/a AG top 10/AG podium) but also the last thing I want to do is interfere in someone else's race, especially if they have money on the line!