I’d encourage all those who feel miffed about their category assignment to still compete. If only the people who are happy about their category show up to race then Zwift will only hear from happy people and will consider this a success.
I know with the autocat events I would regularly post how enjoyable it was to be dropped (along with half the field) within the first quarter of the race and watch the lead group disappear up the road while they were tootling along at Z3 heart rates. And I’m quite sure that WTRL took notice of those posts and made appropriate changes to their system. Oh, wait. That’s right. They just stuck their fingers in their ears and pretended everything was great.
Still, at least these events aren’t being run by WTRL so maybe, when a bunch of people get the crap beaten out of them by A cat Zwift will pay some attention to the ride reports.
BTW, what is MAP? I only know it as Manifold Absolute Pressure.
I have been looking forward to this, the w/kg system has some weeknes. But this must be a bug. Im a 103kg C cat rider, about 320 watt 20min and 3.11 w/kg.
I can hang on for some time with B riders on a flat short course. But hey, only A cat open for me?
I guess only light riders will race in C now and ofcorse be super happy and give you good feedback because all heavy riders are gone racing on the back of the As.
MAP is maximal aerobic power, typically estimated as the last minute of a ramp test, which is why I said FTP is commonly set at 75% of this value.
This change from AND to OR is going to wreck racing for all heavier riders who are caught by the absolute watts (MAP) part of the formula. It took me all of 20 minutes to understand this, so it’s not surprising that the might of Zwift didn’t get there in the months (perhaps years) they have spent setting up this farce.
The reason W/kg actually works reasonably well as an equaliser is that zwift uses weight (and height) to determine aerodynamic resistance. For every extra kg, it takes about 2.5W to maintain the same racing speed on the flat. For every 1cm, you need 1W. The upshot is that a bigger rider probably needs about 3-4W for every kg, and they are (roughly) allowed this by the category thresholds. On hills, where most selections are made, W/kg is an even better equaliser.
Under a W/kg limit, heavy short riders do have an advantage, but not a massive one. At the B limit, they are allowed 4W more per kg and use at least 2.5 of this on the flat and all of it on the hills. If they are a little taller, they really don’t gain at all.
Change this to an absolute watts limit and heavier riders are suddenly down at least 2.5W for every extra kg, even on the flat. It’s worse on the hills (where the selections are made) and it’s worse if they are also tall. Anyone 80kg or more in B cat will be completely killed in the first 5 mins. It’ll be much worse than the situation currently is for the 65kg riders, who have a modest disadvantage.
I have not even looked at where it puts me yet, although will also check on the powertrend website where it would place me, ie cat 1-5 as it seems fairly accurate with real life crit racing over in the UK (obv we have one less cat in UK). It will probably match closely with that. I’m looking forward to it. If I’m in B then so be it, should be C, but it is what it is. It is a test event and as long as there is tweaking as we go then we need a start point somewhere. Did a race yesterday with a mass start and a few C’s stayed with the A group so I would be surprised if a few people are not jettisoned into a higher group. EDIT: just checked and I’m B and powertrend places me as a cat 4/5 so nowhere close to the same metrics. Still if we trial it and find we all get blown out the back then they can adjust the metrics. Someone has to win it I suppose but it certainly won’t be me
My issue with using that 5-8min value is that in a race scenario it’s very different to being able to pootle along then smash out an effort when just riding or doing something like the socks 4 watts hill climb series
My 5min value has increased the last 2 hill climbs due to being able to take it easy then smash out the climb, under a normal race I’d be nowhere near those efforts and I’m sure that for the average person it would be the same
@xflintx Hi Flint, what’s the thinking behind the courses/routes you’ve chosen for these races - have you chosen different routes to see how they affect different types of riders? If so, does your feedback survey ask people which route they competed on?
Firstbeat is what garmin uses I believe? Max HR is pretty easy for Zwift to get, but it also needs resting heartrate. You only need to do a quick Google search to see that there are big issues with the firstbeat data versus real VO2 max even when Garmin has so much more data than Zwift. Muscle Oxygen Training: VO2 max by gas exchange Vs Garmin/Firstbeat - my data
It’s like the 220-age max HR equation, there’s a line of best fit but a huge number that sit a long way outside it.
I think even the mention of VO2 max is just a misunderstanding on Flint’s part. See the comment further down for the model that is likely being used.
I am hoping that Flint will communicate the cat boundaries today.
He mentioned FTP being CP/W’ and also has mention MAP and VO2 max, but also that they are using 5m-8m power as the the input.
I think there is some confusion with the terminology which hopefully will be clarified today My guess is that they are using a number of max power values from your history to create a curve and using the calculated CP/W’ to place you in the category based on certain power values (Flint mentioned 6m and 8m).
There’s a calculator here if anyone wants to have a play with it.
For me these power values:
Gives me two numbers. CP and W’.
CP is like FTP, W’ is how much capacity you have above CP. Maybe Zwift is calculating this curve, and then determining the category based on certain modelled power values - maybe 20m and 6m as an example. Here is my modelled 20m and 6m power:
20m:
6m:
If one of these > cat A boundary, then min category is A.
Fantastic , been a long wait but finally the simple start point implementation.
Assuming it works as described I think this will be the great leap forrward needed.
I see the “Auto Categoriastion” folly is still being mentioend but hopefully just like other great leaps forward the Zwift team will realise from the feedback that all we need is simple controls , not over elaboration and overcomplexity ,
Why oh why oh why aren’t we getting what we have been asking for for years, and what you @xflintx promised yourself very recently - simple pen enforcement which would have “just worked”?
Instead you’ve opened up a whole new can of worms by trying to redefine categories (which you explicitly told us that you weren’t going to do), which will then be bogged down in a mire of complaints about being in the “wrong” category, and widespread implementation of even the most basic anti-sandbagging will be even further off.
This is quite ridiculous and very, very disappointing.
Where can I see the values Zwift has calculated for my VO2 max or my MAP?
I have an actual sports test I did so I can compare values, would give me confidence the right values were being used.
I have entered Mondays event and feel ready to be slaughtered. I feel doing a B race over 5 laps of the Champs is a major over estimation of my abilites.
Why I feel this is I am currently a C and in the recent TdZ I would find myself in a group holding around 3w/kg (I was still working) but could not go for a sprint finish like the rest of the group seemed to do. How am I going to hold with a group doing 3.5+
Here is hoping all the other B’s on Monday feel the same as I do and it feels like a good race. Not holding my breath that this will be the case, and in all probability it will be blowing out of my a** after 5 laps.
Oh that is sadly disappointing if its true , why cant Zwift just listen to sensible simple advice and have to go off on a jolly over complicating things . I hope the feedback will rail them back then … otherwise its just goign to be anti sandbagging version 2 … a long slow hiding to nothing .
Will stay positive for now . But feedback will be honest of course … in the appropriate place.
