Pack Dynamics 4.1 - Test Events

Did this evenings race and I agree with the observations from other riders.
Changing position(moving up)within the pack requires a lot more power than with pd4.
Tried dropping of from the pack a few times and it felt like the draft from the pack dropped off faster than usual
I had steering on for my Kickr Bikev1 and the indicator showed steering as being on. However I was not able to steer and PU button did not function.
I found myself placed out to the left quite often during the race and having the ā€œclose the gapā€ message shown even though I was riding next to the middle or front of the pack.
RPE for the race was definitely tougher than a similar race I did with PD4.
As @Aaron_Bleakley4665 wrote one rider escaped and had approximately 30 seconds he managed to stay away and looking at the results one by one second. His average w/kg was 4.1 and most of the chasing pack averaged around 3.8-4.1w/kg
The movement in the pack doesnā€™t feel natural. It requires too much power to be able to move forward in the pack.

Happy to keep helping with the testing. Keep up the good workšŸ˜€

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For what itā€™s worth, moving about the pack wasnā€™t a noticeable difference for me. It maybe felt a little more position stable, but I had no issues moving about at will.

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Observation from D cat ā€œraceā€ at 5PM Eastern:

There were only two of us. I rode just a few minutes but I observed what others described. I was drafting the other rider and then tried to pass ā€¦ I was going 1-2 w/kg higher and there was no movement to pass. Just stuck behind. So it can be reproduced even with just two riders.

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Did ā€œCā€ race at 5:00 EDT. Small group. Went off on my own towards the start, then slowed to let two others catch up and did a bit of TTT until #3 dropped and we were left with two. Eventually, we were caught and left in the dust on the last KOM by a solo rider.

I found it extremely difficult to move to the front to take my turns. I couldnā€™t do it, even at a sprint (though Iā€™m not a great sprinter) unless the person in the lead backed way off the power. (I also think I tended to waste energy when I wasnā€™t in the leadā€”I donā€™t think I needed to pedal as hard as I did to keep my positionā€”but that was more a matter of my inexperience, I think.)

TLDR: Very hard to move from #2 to #1 in small group.

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Similar experience in my C raceā€”I was putting out at least 2 wig more, sometimes it seemed like 3, without being able to pass. But no issues moving within the pack that existed at the start.

This is what I notice with Dejan video and the draft date:

The narrow cone is very narrow, maybe 1/3 or 1/2 the original width?

When riders pull away in a breakaway or when they put power down, the stretches the peloton. This means any rider that isnā€™t lucky to be directly behind a rider will get little to no draft as the peloton is stretched.

This turns the race into random luck. When an attack happens are you lucky to be position behind directly 1 rider or are you on the outside of the pack.

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Positioning yourself without a steering is a race craft Skill not luckā€¦but that was before when you were moving freely in the group. Now that moving is almost impossible itā€™s a lottery.

I have another Theory of why passing riders was harder.

When the Group/Pack was compact you could move without any hard effort but when the Group/Pack was stretched out it was almost impossible. There is something when draft is changing from high to low draft with rider infront of you that is blocking you from free movingā€¦when the draft is always high itā€™s not a problem.
And another factor is that you need +3km/h for autobraking to be turned OFF but you canā€™t accelerate when you are behind another riderā€¦itā€™s like autobraking is always ON.

How long your NET Power needs to be higher than the rider not drafting to pass him? Is it (1s, 3s, 5s or 10s average?)

Another Comparison from the Test with PD4.1 vs PD4.0ā€¦you can see my effort was much higher for more than 2km/h slower speeds.

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The logic is that itā€™s harder to overtake a rider that is not getting any draft.

Is the issue that there are loads of riders not getting any draft according to the system, due to the way the draft cone works? (and that it is narrower).

Hypothesis examples:

Rider at side of pack not getting draft. Canā€™t overtake them.

Rider in middle of the pack on your screen, might be at the side of pack on theirs. Not getting any draft.

Maths to determine the ā€˜rider in frontā€™ and whether they are drafting or not may be wrong.

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The problem is also overtaking rider that is not draftingā€¦it takes way too much power and itā€™s almost impossible if you donā€™t have +3km/h.

Results look fine now.

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Thank you all for the feedback and recordings!

Definitely something is not working like it was supposed to with some of these overtaking situations, itā€™s too aggressive. So Iā€™m back to work on the proper fix.

Also to address the questions around the draft cone width. The changes made were essentially for two reasons:

  • in the previous PD4 topic discussion, there was a lot of talks around realism and physics, so we decided to bring this PD4.1 package with a set of changes that are in theory more close to real life physics. One of them being the width of the draft cone, that currently is too wide.
  • also in line with that change, the goal would be to see how the whole pack would behave in terms of speed and draft feel (thatā€™s the part where we need the feedback), in another effort to further reduce the forward churning.

I would also like to run another set of test events next week where you wonā€™t (or definitely shouldnā€™t) see this kind of aggressive blocking behind other riders.
However I donā€™t want to disclose the changes so I donā€™t spoil the tests.

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Draft cone width is one of those things I think is better left game-like. Especially when you canā€™t control your position in the pack laterally.

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A narrower draft cone with no blocking may be a good test. Itā€™ll force the pack to string out more and slow it down a bit.

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Could this be related to draft cone changes? Narrower draft cones might mean there are pockets of no draft in the pack, especially if the pack is stretched thin.

You can see on my Stream that i always have draft but i canā€™t pass a rider. I never felt the cone was to narrow because autobrake was to high always keeping me in draft.

I think it was mostly a visual thing. Had the avatar moved into the wind, or had some other cue that you werenā€™t actually ā€œstuckā€ behind the rider in front, I think the experience would have been better.

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Itā€™s definitely blocking. Even side by side, 800w doesnā€™t not overtake 250w in any situation.

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How do you anchor your Sterzo Smart? I have a problem with it sliding around on sprints as I pull the bike on alternating sides. Thatā€™s gotten worse since I got a rocker plate last week, but, even before that, I would end up with it moved/rotated a fair bit. Before they re-started the steering push, it wasnā€™t the end of the world if it ended up a bit angled as Iā€™d still be able to hold my bars straight; Iā€™d just not enable steering. Now that Iā€™ve had steering enabled for every ride for the last week or 2, the fact that my Sterzo smart is moving is becoming a problem. I have to wrench the bars hard to pull it back to center and then countersteer to make up for that.

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I think any time you move forward you should be moved to the outside of the pack. This would both visually show that youā€™re in the wind and reduce churn a bit as moving up would require more effort.

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