Anti sandbagging and other areas that need development and communication

I said there are two types of riders - those deliberately staying below cat limits and those that can’t, or are unlikely to, exceed the limits due to the nature of the system. I then gave clear examples of where that personally held me in the lower cat longer than it should, and that even as a mid-to-higher cat A I am still rarely breaking the cat B limits.

Then you disagreed, and said the same thing.

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I didnt disagree about how it came about, I disagreed that both are a product of a failed system with regard to cruisers.
You were not a cruiser and the general point wasnt about genuine racers, you were not holding yourself back. I even referenced course profile in my later post about extrinsic factors that hold genuine people back…


I wish someone could just explain to me why it would take so long to activate pen enforcement. Just turn it on now in a few races and tweak/iterate as necessary.


To paraphrase Flint, they cant implement helpful features without the right buy in & sign off by product managers as they are now to big a company plus they want to test this and get it right, as opposed to the monthly updates that undertake very little testing and is hit & miss on the improved experience scale.


Yep, Flint just the conduit for communication. As for the Product Managers, don;t envy their jobs, managing a product that is so broken, not something I’d be proud of

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It so happens I’m also a product manager. The job is fun, but yes you’re right: there are a lot of shards to pick up.

As Lee said, part of it is buy-in, and as I’ve said before and will say again: it’s about not implementing a feature real quick so that we create yet more work for us to address later.

I can tell you this week has been huge for competition internally, and I’m really excited to start this boulder rolling down the hill.



This sounds good, and since you say it’s huge, given the saying “under-promise and over-deliver”, I’m expecting something spectacular! :smiley:


Have you considered how you are going to get sandbaggers to take part in these races to test it effectively?

If the test is effective then people won’t be sandbaggers. Also, if current sandbaggers don’t join, that’s also effective in my opinion.


This is what I want to hear! :grinning: So we can finally stop people saying “they’re a sandbagger”, “they’re a cruiser”, “they’re not a sandbagger/cruiser, they’re just a sprinter!”

I’m looking forward to having rules enforced in advance. At this point I don’t care how much they suit me, I’ll just be happy to know there are rules! And to know that if they don’t suit me, I’ll have something I can work towards without being afraid people will say I’m sandbagging/cruising!


i solemly promise to take part in the tests


If I remember correctly, you are under the 250w threshold?
So technically not a sandbagger… I’m sure we raced together and you came second to a guy using sticky watts in London…

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i am, but the 250w threshold is IMO a bit too high because it assumes everyone who is light has a flat power curve. so people like me, who are good at 1 minute efforts, are extremely advantaged

edit: i remember that race, small world

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I wonder if this means
this week there’s been lots of competition between internal teams
this has been a big week for us in the ‘competition team’, where people throughout Zwift have really got behind us!

My other half takes full advantage of it… She is C cat in mixed races. Holds 4.3wkg for 20min whilst under 200w for 95%.

Anything with a hilly finish she solos off dropping people left, right and centre…

As I’ve become more experienced with Zwift racing, I’ve come to the realization that sandbagging and cruising are a lot closer in total percentages than I initially understood.

Obviously, when you first encounter category cheating it’s the obvious sandbagging that is most apparent. Pen enforcement will go a long way to reducing this issue. However, races will still need in race protection. Something like the cone system. Yes, I’m fully aware that in it’s current guise it fails many lightweight riders. What an improved system would look like is a tricky problem. It will need to be very rapid to protect lower category races.

After coming to terms with sandbagging you’ll likely enter the cruiser phase. It’s where you begin to understand that it is an equally large problem. It seems very common in B grade. Maybe, slightly less so in C. It’s a very complex problem to solve.

For interests sake I looked up the top sprint KOMs in Zwift then back tracked the various riders history. What I found was hardly a surprise. Absolute rubbish. The performances amateur athletes are performing in their garages are utterly ridiculous.

I’m a sprinter myself and am very familiar with the numbers required to win IRL and on Zwift. One of the performances I noted was a 59kg rider that rode at 5w/kg+ for a full race then, hit a 24w/kg sprint for 15s. This by the way, would make him the best road sprinter to have ever lived on the face of the Earth.

The rider had dual recording, but somehow that didn’t correlate with their performance. They also had radically improving performance over a short period of time. Obviously, cheating in some intentional manner.

Below that I noticed many B riders were able to ride at their supposed threshold for an entire race, then ramp to say 8w/kg for a minute and off the back of that, hit a 15w/kg+ 15s sprint. Yes, some athletes could do this. The sheer volume of riders on Zwift able to execute this sort of performance in B grade. Totally impossible.

What it demonstrates is the large number of riders either deliberately or accidentally riding below their actual performance level for a majority of a race. Leaving them able to execute a superhuman final effort to win.

How this is all policed is far more nuanced than just category enforcement. It is going to require many back end metrics. Some of them new tech. So, I expect cruising to be a problem for an extended period.

I have a suggestion for down the road @xflintx

I feel a simple look up table based on all time absolute peak performances. If a rider breaks those metrics, they should be made to verify their performance in some manner.

I feel these metrics should absolutely include short power durations, not just FTP. If a rider breaks world record 15s, 1min, etc metrics it should immediately trigger an investigation.

Even further down the road, these could include prior work completed. Meaning, yes a track sprinter could maybe hit 24w/kg for 15s. However, there’s no way they do this after 1 hour at threshold.

So a time in zone, followed by peak performance equation. It’s obviously, very difficult. Smarter people than myself would be required.

Just a thought for the distant future.

Thanks again for the update. I’m looking forward to the test races this month.




Please no, not the cone system.

I think that if organizers start moving the goal post around we won’t see people focusing on x w/kg limit. One race you will race as a top B but the next you will be a bottom A. that will make things very interesting.


i agree with your general point but i hate that stupid chart. you can probably go on slowtwitch or timetriallingforums uk and ask dr coggan himself about the athletes he tested, but when he made that chart (decades ago, i might add) those 5s and 1min efforts were taken from 90kg track sprinters. there are people who are completely off the scale.

calum brown is a UK hill climber who can produce a 13+wkg minute at under 80kg. ed laverack produced something like 7.2wkg for 11-12 minutes to win the UK HC champs a couple years ago