Light Riders not part of Zwift

This is a wrong assumption. Given the the figures you suggest above i think the lighter rider would easily win that race. Would be good to see any data on this if you have it?

taking a recent TT as an example.

Richard Haigh 336 93kg
Stewart Sayer 306 75kg

The lighter rider finished nearly a minute ahead on this sub 30 minute TT course. Yes he ended up doing 4.1w/k compared to 3.6w/k but i’m sure if he did slightly less maybe 3.8 w/k he would of still finished ahead of the heavier rider.
Also from doing many TTTs as lighter rider in a team i know i have to push hard to keep up but not near the power that the heavier riders are putting out.

Lighter riders are at a disadvantage particular in the lower cats where there are heavier riders cruising. As you go up the cats the only way riders can increase their performance to the levels required is to reduce weight.

What I would like to see from zwift is two things. Stop the sandbagging and possibly look at the minimum power requirements for categories.
Cruising as you suggest can’t be stopped unless we removed the cat system which is an interesting idea as well although i’d like to see in the first option them try to improve the current system

Spot on for me Gordon.
I race at Cat C and weigh in at 98kg - the norm for me is for to finish lower than most lighter riders with lower power output but higher w/kg.

1 Like

@Craig_Martin_Herd_Of wrote:

So I’m new to B - I probably break some of your analysis, I won a few C races on my way up. I went from being not competitive, to suddenly being competitive, to bumping the top of category in a few weeks - then I wanted to finish the series I was in. I didn’t cruise, but I did avoid shorter races for a few weeks.

No, I don’t think you’re breaking the analysis. If you’re willing to work hard, then you can be competitive for a brief while as you are on the cusp of getting upgraded. A sandbagger you just cannot beat, but a cruiser is not impossible to beat. It’s just that he has the upper hand, which on average will show in his results. But since you’re not monitoring your 20 min W/kg like he is (or you’d be a cruiser) then sooner or later, if your fitness doesn’t deteriorate, you’ll go over limits and get upgraded. The cruiser can be around for years in the same cat. I could show you examples, but I won’t. Like I have said before, this isn’t about individuals doing a bad thing. It’s about a bad system doing bad things to people.

You bring up another important point that I haven’t mentioned myself although I’m painfully aware of it. Another of the many flaws of the W/kg system - distance! In a way you can only be competitive in a cat (unless you are cruising) on a certain distance. The stupid W/kg system doesn’t take distance into account. Typically, results-based cat systems do weigh in distance. The points scheme for races in US cycling go deeper down the classification in longer races and in x-country skiing it’s accounted for via finish time separation (which of course varies with distance).

I’m sure many Zwifters have made the mistake of participating in sprint races while they were on top of a cat with regards to standard 40’ish min races. In a sprint race you can of course do W/kg that wouldn’t be achievable in a 40 min race and so you get upgraded earlier. Which means you are actually below the W/kg floor in your new cat in a 40’ish min race! It’s just so dumb…

@Gordon_Rhino-Racing wrote:

This is a wrong assumption. Given the the figures you suggest above i think the lighter rider would easily win that race. Would be good to see any data on this if you have it?

Well, I didn’t provide data or calculations for the single theoretical case with the heavier 300W rider against the lighter 275W rider. It’s just an arbitrary example to illustrate a point. But I don’t actually think the lighter rider would win in a TT where both riders put out ERG like even Watts. The lighter rider will be faster than a rider at 275W with the same weight as the 300W guy. This is because the lighter rider - as I discovered only recently although others knew already - does suffer less air resistance. But this difference in air resistance is very small. I could be wrong, but I highly doubt it could account for a whopping 25W in this scenario.

What I did provide data for was that riders with a weight higher than the race average podium more than the average weight rider. And this is an undisputable fact. What the results say, literally, is that I could sample 40 new races a thousand times and the result would be the same every time, i.e. heavier riders do have an advantage in C and B (and of course D although I didn’t include them).

What I didn’t discuss (and didn’t study) was that while there is some sort of correlation between weight and win rate, it is not linear. You don’t win more the heavier you get obviously. Rather, I’m guessing it’s something like this, if we transpose a graph of win probability to weight on top a distribution chart over racer weights:


So on the X-axis we have rider weight. And on the Y-axis we have both n = the total no of racers we look at, and also p = win probability.

So weight is a typical normally distributed human feature, and A here is the average weight of racers in a certain cat. B is the average weight of winners in the same cat who of course also have the highest win probability. So most racers will be fairly close to the avg weight. But most winners actually weigh a bit more than the avg racer weight. At some point the additional weight will start to damage win probability though and so p starts to drop off. Why is that? You have it figured out already but maybe others don’t. It’s because of this:


So the first rider is a bigger and heavier guy than the second rider. No 2 gets a wee bit less air resistance in Zwift due to his lower weight and, possibly, shorter height. But it doesn’t make up for No 1’s bigger muscle volume. No 1 can push much higher Watts at 3.2 W/kg than the No 2 on the flattish (like the standard Zwift race) and that will translate to higher speeds and thus more wins on average. The key thing here is that both of them are capped at 3.2 W/kg or they get a DQ. So the lighter rider can’t compensate with a higher W/kg and win.

The No 3 guy, I would say, is past the point where his higher weight gives him an advantage. The two first riders have roughly the same body fat percentage, so bigger size = more muscle. But No 3 has a higher body fat percentage than both the others and excess body fat doesn’t do you much good in a hard 40 min race in Zwift (I can attest to that). And so the win probability curve starts to drop off beyond a certain point because people only grow so tall and thus they only get so heavy, and beyond that any extra kg’s is body fat.

(The exception here, maybe, is that people who used to carry a lot of overweight and then lose it, working hard in Zwift, are often damn strong because their muscles used to have to carry that overweight around - they often come out of a weight loss like rockets in Zwift, a little reward for the struggle perhaps, well deserved.)

In your own example the lighter riders wins and shows a much higher W/kg. That’s great! Why would you want to rob him of the win by pasting a big fat DQ on his race result? Why even speculate whether he could still have won doing 3.8 W/kg? (I’m not so sure he would BTW.) That is the same as saying “Could he have won on ZP if he had cruised the race?” (4.1 is OK, I know, but you get it.) So yeah, you understand why I’m against the W/kg system. And I’m sure none of us would regret a move to a results-based ranking once it’s in place. It would be so worth it. There is nothing to lose, because the system we have is crap.

You’re absolutely right about the way the importance of weight changes as you rise in categories. You see it clearly in data. Even so, a higher than average weight in cat B, where people are clearly slimmer on average than in C or D, is an advantage. The results are there in my little study, no doubt about it. And then in cat A, where there is no performance ceiling, you have your muscle volume and your fitness, whatever it is, and only stand to gain from a weight loss, up to the point where it starts to hurt your performance of course.

@Phil_Waters wrote:

I race at Cat C and weigh in at 98kg - the norm for me is for to finish lower than most lighter riders with lower power output but higher w/kg.

But then you’re not on top of cat C, if there is still room for a higher W/kg! Once you are just below the 3.2 W/kg ceiling, then I assure you that you will have an advantage over lighter riders. They have no counter to you, none that wouldn’t result in a ZP DQ anyway.

2 Likes

I guess I don’t see it as a big problem. The sandbaggers (‘cruisers’ as you call them, but to me that’s the very definition of sandbagging) aren’t doing anything but stunting their own performance. People who are trying to improve will surpass them.
The problem is that you can’t identify this behavior with sureity, and whatever your system is, people will attempt to take advantage like this. My IRL bike racing is BMX, and in our sanction you move up after a certain number of race wins. Sandbagging is prohibited, and enforcement of the rule against it is at the discretion of track operators - the punishment is forfiet of points earned and being credited with the win anyway. But even if it’s podiums or top 10s instead of wins, people will try to finish 4th or 11th to delay the promotion.
I love what the race director for our 10 week league has done in including Tempus Fugit and Bologna TT’s in the 10 week series. I saw an interesting request on ZP forums to delete a period of data due to ‘miscalibration’ that included one of those and another race that happened to put someone up into the next category. It certainly appears that a person that’s been at the top of a category for a while and then makes that kind of request wants to stay there instead of moving up, I’d agree - but someone has to make a judgement call, and currently, apart from it not being against any rules, no one is given that authority or wants to make those calls. And ‘innocent’ people will get caught up in trying to police sandbagging as well. (I don’t like to call entering the wrong category sandbagging. Cherry-picking maybe)

1 Like

Over time, yes, they’re hurting themselves if they keep doing this. But in each race, they’re upsetting plenty of non-cheating racers, some of whom might be put off Zwift racing because of this.

And if there are enough doing this on just an occasional basis, the they’re not hurting themselves at all and are only hurting others.

So they’re far from only affecting themselves.

4 Likes

@Craig_Martin_Herd_Of, I would have to agree with Steve here. The thing is even if people might still be trying to delay an upgrade by finishing just outside the points scheme (or you can obfuscate going the FIS route to ranking calculations instead), then while they are stalling at least they are not winning. Their presence would distort the race texture somewhat although not nearly as much as a sandbagger or cruiser with an intent to win but they are not competing for the podium at that time. It would be better. At this point almost any change would be better.

But it’s a moot point. With the ZwiftPower September Update post, Zwift is making it clear where they stand. I can’t interpret it as anything but an indirect reply to the discussions we’ve been having lately, a big middle finger in the face. Zwift racing is to remain the uniquely stupid sport among sports just… because?

Anyway, I totally agree that sandbagging is a correct term, lent from horse racing originally I guess, for what I call cruising. It’s just that the term sandbagger has been misused so much that in a race where people from higher categories join (like every race 24/7) and then go flying right from the start, the legit racers go “Look! A despicable sandbagger! It’s his fault we can’t get fair racing in Zwift!” And ZP goes “Yeah, we saw that, we’ll DQ the despicable sandbagger for you so you get fair racing. There! Now it’s fair again.” and Zwift goes “Hey, we’ll spend our limited dev resources experimenting with adding a funny-looking geometric shape on top of the head of the despicable sandbagger, so you really can tell you just lost to a despicable sandbagger”. And then many legit racers think they’re good. They’re not.

So another term was needed to reclaim the issue. I did a forum search but I just can’t find the guy who accidentally coined the term for me. He should be credited.

While the term sandbagging describes the phenomenon well, the term cruising does too, perhaps even better. Because sandbagging sort of hints at a malicious intent. Cruising doesn’t. Some people intentionally cruise to get on the podium, maliciously. Other just like to cruise in general, it comes natural to them, it’s the way they want to use Zwift, and that’s fine. But if they also happen to be on top of their category, then they win far more than riders with a natural tendency to work hard. Not so fine for various reasons IMO, but the problem isn’t the sandbaggers, cruisers, cherry pickers, HC flyers, whatever. It’s the cat system and race rules. You get the racers you deserve in any system.

1 Like

There is definitely something wrong with the algorithm at the low end of the scale (I am 46 kg with very low power). Why in a large pack am I having to ride at 3.2+
wkg to try to keep up with a leader at 2.5 wkg - and still drifting out the back – but if I get to the front (or even in front of the fence) of the pack I can ride at about 2.7 wkg and still stay in front and even get time on the leader? I appreciate I have to put out more power to pace with higher power riders (who will most likely weigh more), but this makes NO SENSE.

3 Likes

Completely agree with you.

Definitely late to the party here but wanted to chime in after my experience with the Future Works anti-sandbagging races. A better ranking system, based on podium finishes and past results, is completely needed. This is coming from the perspective of a lighter, female rider.

If Zwift implements their anti-sandbagging algorithms that are currently being tested in Crit city races, they’ve effectively made it impossible any light rider (more often women) to win a race or even come close. Not that my life goal is to win a race, but it’s much more motivating to be jockeying for position in the top of a cat than riding alone in the bottom of the next one. Problem is, if I ride hard enough to stay in the lead pack, inevitably, I am kicked out because my w/kg is too high compared to the almost-always heavier riders surrounding me. In the past two Beta crit races I’ve done, I’ve seen all of the females, myself included, and the lone 12 year old boy get “green coned” in the large lead pack. Why should we get kicked out for riding above cat especially when those surrounding us are not? That is that part that makes zero sense to me. And it’s not like I’m pulling the pack along - I am riding in the cat that Zwift power says I should be in and generally am working my butt off to stay there.

I have no issue going up a cat when I ride in women-only races (i.e., people generally closer in weight to myself), but those are few and far between. For mixed gender races, there is no way I have the sheer power output to match the men in a higher cat.

Anyhow, my 2cents. Thanks for reading and happy riding all!

2 Likes

In real life the smaller lighter rider will have a smaller lighter bike…

You see big guys with HUGE bikes, which need stronger frames, and have MORE material…

I used to ride away from the heavy guys up the hills, but now they often ride away from me… NOT in the real world…

1 Like

Zwift is not the real world and there are many users without powermeter or cheating. I am not sure the big guys riding away are always so strong.
I am 188 cm and 89 kg, no chance to ride with lighter riders uphill. Much better downhill :grinning:.
For me (NG eco powermeter outdoors, Tacx Neo indoor) is Zwift OK, my indoor experience is very similar to real life.

@Catherine_Lee, that’s exactly it. Sadly.

And I wish people could stop derailing serious discussions with anectodal evidence. That person so and so is heavy and slow (or likes to Sunday ride his races) has absolutely no bearing on the underlying problem, which isn’t about people but the logics of the race rules. And the race rules are completely absurd. Anyone with half a brain will realize that.

What p1sses me off to no end is that:

a) Zwift persists in claiming that racing is a margin phenomenon (and hence that they don’t have to spend any time on making racing fair) although it’s overly obvious from just a quick glance at the daily schedule that racing is hugely important for the Zwift subscriber base and thus for the Zwift brand.

b) Zwift is marketed heavily by elite racing. So you watch a commercial or some live event on TV or some stream. Some tour or race with or without RL pros. Hmm, exciting! And you go check the website and it tells you that Zwift is not just for them. It’s for you to partake in! So you give it a go. Only what you get is not what you see on TV. Because the elite in cat A and above enjoy fair race rules. You get something else, because you are plebs, the lower class subscriber base who stands for 90% of the bottom line in the financial report. But they never told you, that you don’t get what you saw. So you complain about it. Why wouldn’t you? But then you’re told it’s not going to change “anytime soon”, and that you’re just one of those few margin subscribers who “identify as a racer” who they don’t have to satisfy. Scammers…

It’s such an easy fix! All you need to do to get insta-fair racing is:

  1. Enforce categories
  2. Remove the performance ceiling in cat B-D
  3. Replace W/kg cats with results-based cats

(WTRL/ZRL does all of the above.)

It’s child’s play! The ONLY reason why this isn’t fixed already is Eric Min’s stubbornness, nothing else. What drives it is one of those unsolved mysteries, up there with Stonehenge, the pyramids and Atlantis. And now he’s hiding behind WTRL and let them do the job for him. Just like last time, with ZwiftPower. See how that went… (I actually believe much more in WTRL than in ZP, but they cannot shoulder a responsibility that belongs to Zwift, and it’s just one race per week anyway.)

First you have to pay them. Then you need to wipe their @rses for them. And they don’t even supply the tissue. But you’re hoping they will grow up some day. Do their own wiping. Only they don’t. And once you grow tired and give up they will just blow blue smoke on someone else. Bring your own tissue. But it’s not going to last forever. Why can’t they see that?

7 Likes

You couldn’t have stated this more perfectly!

Funny old thing. Came here after my very first hard effort rides on zwift. Im 70 kgs and was literally gobsmacked at the effort I was having to put out to remain in a C group ride. Afterwards I did a quick look at other riders efforts. Riders around 85kgs plus seemed to average around the 2.7w/kg where I was around 3.2kg.Out IRW I have never noticed such a discrepancy but what would I know Ive been a competitive cyclist for 40 years plus. Thanks so much for your post it opened my eyes!!

Thank you, @Nick_Harwood, I try. But you will notice yourself that a surprisingly large number of zwifters are like anti-vaxxers, completely resistant to facts and figures. And so you will hear again and again that heavies are disadvantaged and that racing in Zwift is fair as long as you sign up to Zwiftpower. None of it true of course.

If you want a deeper analysis of the problems with Zwift racing, then please refer to my blog. I have since given up on Zwift racing and focus entirely on WO’s now, currently doing the Build Me Up after a covid infection.

1 Like

That explains a lot, thanks for the link. :thinking:

1 Like

since when is 85kg big?
im 110kg and get passed by most people on hills !

The Light Riders’ Curse makes it nigh on impossible for most women to race in mixed races as we tend to be a significantly lower weight than the guys. You’re either dropped because you can’t keep up the higher w/kg or else you have to output a w/kg that’s too high for your cat, just to stay in the group. Given the small number of competitive women-only races that pretty much eliminates us from racing competitively.

2 Likes

It’s not about gender. Is just about power output. Justo choose a proper CAT based on fitnes level

W/Kg is hopeless as a metric as categorization in any form since produced watts do not scale linearly with weight, and a rider’s weight is not just muscles and fat in a fixed relation.

1 Like

Imagine a short flat race (the usual Zwift event) with a 100kg rider at 2.5W/kg and a 50kg rider at 2.5W/kg. Now ask yourself which one’s more likely to be a woman.