Watching the Tour if Colombia TTT with road bikes I expected some rotation paceline. But, it seems the aero or power arrangement of the normal line wind out.
Soooo, other than fun or skills, why do a rotation line if it’s not faster? I think some folks think it’s faster. If it is, why aren’t pros in a road bike TTT doing it. Is it just a skills building thing?
I don’t know. I was told it’s faster.
I couldn’t find a pro breakaway doing it either in a fast YouTube search. Talking like 8 folks in a group or so.
I assume the TTT consensus is to swing wide to preserve aero and single line. Rotating it seems you halve your draft group distance for the advancing group.
So, what’s up with it wise sages? What’s fastest?
Yes it is faster but you do not win a stage race by winning a TTT. If your GC hopeful is a lightweight climber he could actually slow the team down by taking a pull on the front. Or it maybe important for him to have a easy day for an mountain stage the next day, Better to use up a domestic or timetrial specialist. I would say the best video to see a team working as a team in a time trial would be the world championships.
To me, one of the major benefits of the rotating pace line is that it evens out the work among the riders. It’s frustrating when people just sit on the back of a breakaway to win the sprint at the end. If you can get everyone rotating in a pace line, it ensures everyone is putting in as much work as you are.
I’m not sure why they don’t rotate in a team time trial on road bikes. My guess would be that the teams actually don’t want the work load distributed evenly. They have riders who are really good at time trialing, and those riders can stay on the front longer to burn themselves up while the GC riders take short pulls to stay fresh. And you wouldn’t want only half the team rotating and the other half sitting on, because rotations aren’t efficient with 5 or less people. Six riders rotating seems to be where the efficiency really starts to help keep the pace fast.
Edit: here is a post from Steve Tilford (RIP) about pacelines. He says 7 is where it starts getting efficient. I was close. http://stevetilford.com/...ing-out-of-the-wind/
Since the teams only have 6 riders, I guess that kind of helps answer it.
As mentioned, a double paceline only really works if people are taking equal pulls. So it’s good for a break, to remind everyone to do the work (and to keep them honest). For teams it works well for really strong roulleur teams (like the old Raleigh and Panasonic teams of the '80s where everyone is strong and well versed at TTing), but not for teams with more variation in TT ability (typically those with some lightweight climbing specialists).
What’s fastest?
It’s complicated.
In a small group where people spend a lot more time pulling than they spend circulating to the back, switching to a rotating paceline will effectively make the group twice as wide and half as long, which is a potentially bad thing for the overall CdA of the group. Or to put it in plainer terms: rotating pacelines have two people pulling 100% of the time, whereas with small groups, you can spend a lot of the time with only one person pulling.
Taking this to its illogical extreme, imagine a two-person group trying to do a rotating paceline: they’ll be riding approximately side-by-side almost 100% of the time.
As the group gets bigger, this problem can get smaller and eventually go away. If a normal paceline is so long that there are always a few people circulating to the back, switching to a rotating paceline where exactly two people are always pulling doesn’t really make things worse than they already are.
A major reason to use a rotating paceline is that it smooths out your distribution of efforts by replacing rare huge pulls with frequent tiny pulls, so it can be easier on the matchbox. It also inherently encourages different riders in a group to do similar amounts of pulling, which makes it a diplomatic option for large breakaways.
One really major use case for a rotating line is in an echelon with strong crosswinds. When a paceline needs to sprawl diagonally to get a good draft, you quickly run out of real estate on the road. When this happens, riders at the tail of the line must either line up straight along the side of the road (where they aren’t getting much draft), or split into a second echelon (and splits are scary in races!).
By setting up an echelon as a rotating double-echelon, you can roughly double the number of riders that can participate in that echelon before running out of space on the road!
In a TTT within a stage race, there are major reasons not to use a rotating paceline. Like, forcing a TT specialist to put in huge pulls at the front might allow you to keep your GC guys better-rested for the scary mountain stage the next day. And, if a group consists of riders of very different styles, making them take equal pulls can be a poor choice regardless: that’s one reason to avoid rotation even outside of TTTs.
Straight paceline is always faster, unless there’s a crosswind and you have 6 or more riders.
Takes a lot more skill and timing to do a rotation. Too often the rider at the front of the advancing line has to do a surge to pass the receding rider. This kills the legs. Only time you should ever accelerate is at the back to rejoin the line.
Rotations are only as fast as the weakest rider. Very easy to destroy a break or a chase group by subtly messing up the pace. Seen sprinters do it many times.
If you’re a sprinter and you’re in a break and the gap is solid then get a rotation going. It’ll kill the diesels in the group.
Exceptions: Sometimes at the end of a race you’ll see small groups rotating - nobody wants to be at the back when the attacks start.
If, for some reason, pulls are very short then rotation allows this better. If pulls are more than few seconds then straight paceline.