Im presuming zwiftracing is taking fixed point reads for the CP - 1/5/20min efforts.as that is the data it is pulling from zwiftpower
As we all know Zwift riders like to substantially lower their 20min power say against their 10min power - Hence that Zwift racing CP metric is quite misleading - Im not sure I would publish it, the 5min compound score is probably a better value to go with which is currently being looked at I think.
Zwift appears to be focused on the 5-8min range to get your CP metric - Hence improving 2min power can steepen the curve and lower your CP and therefore category available to you.
āCritical Power is a better calculation that takes in to account all of your best efforts from 2 minutes all the way up to 50 minutes.ā
Shorter duration may have more impact in the way the CP formulation work, that is probably why we can get a good estimate of FTP with 8min efforts and 20 min efforts,
Hi,
On zwift power Iām a cat C, but I am unable to enter cat C races, this has only happened in the last few days. Any answers would be helpful.
Thanks
Zwift Cat enforcement uses Critical power rather than 3 x 20min (95%) effortsā¦
Lots of threads in the wider forum - If you would like to know you CP value and which effort took you over, Zwift dont deem there a need to provide that information currentlyā¦
Please answer me why in the next week I had category B closed first and only A was available. But yesterday B was reappeared again. why? not even 60 days have passed since it was said!
Zwift recalculates your power curve after every ride, so if you did any ride since your last enforced A ride and set a 60-day personal best between 2 and 50 minutes (but most likely on the shorter times if you dropped to B) then it will have changed your calculated CP.
Perhaps as importantly as the daily recalculation of CP based on a rolling 60 day history, the CE system works in watts which means that every time you change your weight, your W/kg changesā¦
no, the proper FTP value that Zwift have for CE seems to be independent of any value āenteredā into your profile section of the game, example is my zFTP showing as being 270 up there with my Vo2max etc, whereas in game profile shows a value of 281 from an upgrade after doing climbers gambit on race 1 of wtrl (Zwift auto updated this value after giving me the new FTP) Iād have to check when I get home in my screenshots to see if it was this race, which if it was that one, as intervals.icu is giving my eftp as 283 for that race, it aligns pretty much, so either the 281 value is now ignored by Zwift or their system has my zFTP incorrect
So Iām guessing that Zwift have the ability to either override the figure entered manually and see your actual number or they are just taking the 95% of 20min best time over 60 days as zFTP, either way they have the ability to know what your real zFTP/eFTP is
If Zwift is constructing a ālivingā power curve based upon every one of your efforts over a 60 day period and, assuming that they express it in terms of W/g vs time (and not simply Watts) then the values they extract from the curve fit and use in your CE categorization, such as CP20, will surely change if you change your weight? Just a thought, I could be well off base?
If this is the case, how often do they adjust the power curve for any rider weight changes?
daily. one of the many reasons why this system is even more busted than ZP, and presumably also why most CE race organisers are intentionally leaving UPG and WKG tags on. and if a race organiser reading this thread isnāt doing that, then they should start
What you are asking for is the ability for users to be able to sandbagā¦ The whole point of category enforcement was to prevent that. Its unlikely that Zwift will release those boundaries.
This is where the current āmax effortsā models all fall down.
For example, If a race is based purely on a hill climb time, you will rest before and after and only do the effort on the hill.
In any other race you wouldnāt be able to match that effort and keep racing throughout.
What makes it worse - bumping someone like Rich for doing a hill climb he probably couldnāt repeat in a race - makes him unable to race at his more realistic level and so heās not going to race at all and more likely to keep doing hill climb races and the such which perpetuates the problem.
I know there is no easy answer though, just feel like all the āfunā is gradually being sucked out of the platform at both ends - by the people who donāt race genuinely/sandbag/etc messing up races and the āsolutionsā to these problems that also penalise genuine racers for posting one good metric on a curve. (and often cause riders to immediately leave races when they are dropped - so even if others get dropped, they end up solo)
There will always be guys who try to āgameā whatever system is in place and while it relies on the user to enter metrics that canāt easily be verified.
Whatever happens, transparency on the categorisation system is a must.
Problem I have is that the categories themselves seem wrong. The calculations are somewhat irrelevant.
Iām 59, have a calculated FTP based on 20min power of about 220 and Iām 61kg. Iāve just been bumped from C to B for category enforcement.
First race for a while I entered cat c and did 3.5W/kg and got bumped to B. I didnāt win the race - not even in the top 10!
Entered the zwift insider short races in cat B - came in the last 10 for all 4! With a 3.6W/kg average.
Problem for me as a lighter rider in flat races is that the heavier riders go off the front at the start at 400Wplus for a few minutes and I simply get blown out of the back.
If I enter a hilly race I would be more competitive but I quite like the flatter ones too.
So the problem is that the categories are wrong (for me at least) for flatter routes because the absolute power of most of the other people in B category are way outside my capabilities.
A suggestion to solve these issues would be to match categories to routes. So for example on Road to Sky which is 95% hill the current W/kg categories are fine but for say volcano circuit which is 95%flat it would be fairer to base the categories on power.
With the system the way it is, it doesnāt matter what races youād like to do better in I donāt say that to be meanāI like climbs, and Iād love to place higher in climbing races. But Iām 90+kgs. It doesnāt work IRL to say that I like climbing and Iād like to be able to do better in climbing races. That doesnāt make me any better of a climber. Bigger riders will do better on flats, smaller riders on climbs.
That saidāI agree with you that it might be nice for Zwift to categorize races like youāre talking about (I suggested the same thing somewhere else). This isnāt IRL, so we donāt have to be limited by how things are done IRL. It would add complexity, but it seems like it would be possible to sort races into āFlatā and āUnflatā categories, and as you say use Watts for one and Watts/kg for the other. Iām one of those people who can get to the front of a flat race and (hopefully) drop the lighter riders and sprint against the others for the line. But Iām also one of those people whose placing would benefit from also climbing against the big folks as well.
Iām not all that bent out of shape about itāIām a good climber for my size, but that wonāt win me climbing races, and I donāt see that as a big problem. Not everyone can excel at every kind of race. But Zwift could categorize races if they wanted.
(Edit: I was in a short (5km) flat NYC race the other day, C cat, and one rider in the chat was complaining that the front group was hitting 300w to 400w for the first half of the raceācomplaining like it was impossible and weāre all sandbaggers. At my weight, my 10min power is in the 300s, and itās solidly in C cat. I can only guess that he was a lighter rider who was upset and wasnāt taking the time to understand that. Different elevation race cats would maybe help solve that.)
Thanks for your reply Tom, I think we are both seeing the issue from opposite ends so to speak.
You as the heavier (and more powerful rider) would always have the advantage on the flat even though youāre cat c and Iām cat b (by W/kg).
So my point really is that since categories are supposed to group riders together in similar abilities; for flat races power should be the main basis for categorisation.
This would probably mean that for a flat race I should be cat c or even d, whereas for a hilly race I would be cat b.
For you it would mean that for a flat race you would be cat A or B but for a hilly race you would be cat c.
I guess weāll just have to keep discussing and maybe things will improve.
I donāt say that to be meanāI like climbs, and Iād love to place higher in climbing races. But Iām 90+kgs. It doesnāt work IRL to say that I like climbing and Iād like to be able to do better in climbing races. That doesnāt make me any better of a climber. Bigger riders will do better on flats, smaller riders on climbs. 