9th June 2023 - Raced this morning as a B cat rider as per normal. Tried to join a B cat race this afternoon only to find I was now an A cat rider! No new records were set in the earlier race. After some investigation it looks like the cat enforcements limits have changed for zMAP (zFTP is the same as it was). zMAP limits for B cat were 4.2-5.4 w/kg, but now seem to have been reduced to 4.1-5.1 w/kg (and I’m 5.123!!).
Is this correct?
Category Enforcement FAQ shows zMAP threshold reduction.
For men/mixed W/Kg…
C >3.2
B >4.1
A >5.1
For women only W/Kg…
C >3.2
B >4.1
A >4.8
No apparent changes to minimum zFTP per pen (150/ 200/ 250W for C/B/A) or zFTP W/Kg thresholds (2.625/ 3.36/ 4.2 for C/B/A) at time of posting for men/mixed races.
It’s now a rolling 90 day evaluation period, from being 60 days…
I wonder if they are back-dating that 90 day period, so going back to our performances around 11th March '23 as of today? 
Hi Steve, yeah that’s where I found the new limits. Did we know this change was coming? And do we reasons why?
Lowering the top end limit from 5.4 down to 5.1 seems like a very big change to me. I suspect a lot of B cat riders are going to be in the same boat as me.
There’s been some talk of another tweak to pen limits in at least one Category Enforcement related thread in the last few weeks, but nothing official was announced.
I guess that’s coming anytime soon and you’ve spotted the changes before the announcement.
The talks of tweaks was partly fuelled by a number of members saying after the last round of pen tweaks, A had its range of ability reduced at the cost of bigger ability ranges for pens B-D inclusive. In addition, if you got promoted to pens C or B (especially by zMAP), you were faced with an impossible task of trying to keep with the masses during the mad Watts race start surge.
Will be intresting to see if the dynamics in tomorrow’s Tiny Races changes for the better!
fwiw, my /feed stats are quoting some 20 and 30 min power now from 3/12, though the stat at 30min on 3/12 is about 20 watts higher than my zFTP figure and my zFTP figure is the same as it was a week ago, so it didn’t shift at all apparently.
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On the one hand, the zMAP tweak with extending the data period to 90 days has meant that a group of riders have been promoted together, hopefully reducing the odds of having to “race” alone.
But on the other hand, having not decreased zFTP thresholds, they have increased the ability range for at least B and C.
And it looks like some racers have been able to sign up into their pre-tweak pen for at least the 1000 Tiny Races, there’s at least one D racer with a 5min effort of 3.61W/Kg in the last 90 days, who should be in C now.
Sorry all, we were going to post this in our release notes yesterday but it got delayed over the weekend.
zMAP has been changed to be zFTP + 25% for each of the category limits.
The calculation period has been changed from 60 to 90 days.
Our support docs have been updated: Category Enforcement FAQ
That’s to be expected. It was their category at point of sign up.
Unfortunately, said racer won two, one silver and a 4th on zwiftpower… Almost certainly won pen D series.
Yeah, like I said, it’s to be expected based how it works. It shouldn’t happen again next week.
FYI - it still says 60 days on the “My Profile” “Fitness” section.
Hi James,
Can I just double check, so as to nip the discussions on Facebook (that you may not be able to see if you can’t see a certain poster), and Discord in the bud.
When you say zFTP +25%, were you being general about the figure or should the new numbers be exactly zFTP +25%? Because it’s been noticed that the table in the FAQs does not correlate to 25%
Thanks
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Looks like +22% is more accurate
Wish it was exactly 25%, cuz then I’d be back to being a B (but doubt I’ll be that lucky)
I really really wish Zwift would just keep all this category numbers secret.
Everytime they post the numbers people try to back calc their category and complain about 0.01 w difference.
Zwift calculate your category and that is what you race in. No questions asked.
Indievelo doesn’t have categories you select a race and 1min before the race they close the pen and move people into competitive groups. No magic numbers to try and sneak under.
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You snooze, you lose.
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People should be able to skew their numbers right now by increasing their weight to lower their ZFTP and ZMAP to get into lower categories. Indievelo doesn’t take into consideration weights so they don not show a w/kg number, they use raw watts and cadence.
They need weight for the cycling dynamics. And they need some form of weight in the calculation of the pens. Weight is part of cycling IRL and virtual. The fact that they don’t show w/kg does not mean they dont use weight in the formulas.
Zwift also use raw watts in calculating power. It is a standard equation. Probably very similar to any other cycling game.
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I think Zwift covered that in post linked below.