Light Riders Being Incorrectly Upgraded into Higher Categories


Yep I proper effed that up.
Don’t now how the 10% drivetrain efficiency got in there.

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This issue seems to be getting muddied a bit with Zwift v IRL comparisons.

Example that I’ll call “A Tale of Two Teammates.”

Teammate #1: 120KG races in a pretty hill race. Stays WELL within category w/kg limits while also making a solo breakaway. Riding alone, in the wind, for many minutes and finishes 22 sec ahead of #2 rider.

Teammate #2 weighs less than half of what #1 weighs. Rides near the front, but mostly in the draft. Gets dropped in the final sprint and finishes in 10th place 8 seconds behind 2nd place and 30 sec behind first place. And gets a Code 7 and promoted to the next category up.

This illustrates why the w/kg system is less than optimal and many of us would like to go to a results-based category system.


You nailed it Mark!

Same here than what I’ve noticed in other apps. None mimics outdoor real rides perfectly but here it seems to be a big issue (Im a light rider too). Besides all other unreal stuff that makes racing Z a good workout but no one should give a huge importance to the final results.


[Edit: I didn’t mean to reference weight. I always change Kg to pounds when reading posts and end up highlighting the number in the process.]

Yes, definitely take results with a sizable grain of salt. I’m still pretty bummed results can’t be sorted on age.

In lieu of results-based cats (while we wait, I guess), I suggest eliminating the cats and make every race a sandbox. You’ll end up riding with the same people anyway.

Why do you think this 2 riders wouldn’t be in the same Cat with Results based Categories. :crazy_face:

The only fix would be Rider 2 wouldn’t get upgraded.

They probably would. not be.
It is likely that rider #1 would be in a higher category based on results.
In the current system, the weaker of the two got the upgrade.

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Well with 4 cats we have now…there isn’t that many room for big moves.

Dejan, the moves are already occurring today. Mark is just suggesting that rather than the light weaker rider being moved into the stronger category and the heavier stronger rider staying the lower one as is happening today, the opposite move would occur to maintain a fair playing field within categories. The heavier stronger rider would move into the stronger category while the lighter weaker rider would remain in their current category.


30km, fairly hilly course, in the end only a 30 second difference being discussed, and #2 was still in the top 10 out of a 77-count field. The spread on the overall c-Cat timewise was over 11 minutes for perspective.

OTOH, if you promoted both teammates to CatB before that race, their times would have respectively placed them next to each other in 46th and 47th place (in a 66-ct field).

All-in, I think it’s correct to say that they should be in the same category, and the problem is that #2 got promoted. Though, by time anyway, she would have fallen at about the 70th percentile had she rode in B, which is hard to argue is a huge misjudgement in the category assignment process.


In a ranking system, where we have no idea how it might work, it seems conceivable that both riders could be promoted (both being in the 15% of the results).

I also would like to understand how in a results system, how it wouldn’t be really prone to sandbagging? Reenacting this scenario… at some point the 2nd place and down riders knew they couldn’t catch up and win, so what prevents any of them just stopping and sitting on the side of the road until a large field of riders shows up so they don’t place well?

Ignoring results where the rider has a significantly lower avaerage power later in the race?

I’m sure there are lots of things that could be looked out for.

1 Like has a feature relating to this, although if you ride to the finish with a lead group and then sit up for the sprint, it won’t do anything about that.


Yes, ‘could be’. Would be is the question?

Something to that effect, yes. That was an original estimate based on our original planning, which has since been shifted due to some extra requirements needing to be met from a technical standpoint. Those new requirements ultimately mean the overall experience will be better.

Right now, I have a snapshot of preliminary scores in hand for all Zwifters from a specific date in time back, and we are working to begin public testing soon, though we need to make sure the scores feel right so those tests are worthwhile for everyone. So we’ve been generating new reports with each iteration of our scoring model and then looking to validate them internally before we bring anything to the public.

So while I have nothing groundbreaking to say at this moment - i.e. dates for release or testing or screenshots of folks’ scores - I can tell you we’re very much headed in the right direction based on what we’ve seen thus far and I’m excited for December.

Again, these are estimates and I’m hopeful, but please remember it’s still not concrete.


Flint, thanks for that update! Gives some of us great hope! You folks keep up the excellent work there and I’ll patiently wait for the improvement.

Also, I just remembered another little improvement that’s related to this. It’d be nice if Zwift notified us when we’ve been moved into a different category. Most of us find out by surprise when it’s already race day. Ok, I’ll quit now :wink: thank you!


I’m very light as well and I’m stuck in A grade category- even though I have no chance against those riders with 5.5w/kg FTP. I’m about 262w FTP at the moment and not a lot of maximum power (less than 600w) due to the results of my crash last year.

I get obliterated downhill and on the flats I need to push big power otherwise people just overtake. I even get stuck at the back of the Coco RP group and need to push 4.5w/kg to get to front of that.

But this system is perfect for certain riders to get lots of victories and not get upgraded as quickly. I don’t think it can be changed without making those folk annoyed that they will be upgraded to the next category.

Using results to categorise riders would really sort things out. If someone gets a lot of wins, they go up to next category. If they want to sandbag, then they don’t win.

I’m unsure if it’s necessary to look at the gap for the winners from first to second as a backup, this could be used by sandbaggers to get a huge gap then back off so as not to look too fast. The idea being they would get away them slow down to roll across the line to a narrow victory when in reality they were too strong for the category.

IRL but that should be true on zwift too, and I think it probably is. This thread has changed course a few times and now seems to be about the category system.

Thanks for the update.

I’m sure others are very happy to see this. It’s been an incredibly long time coming. These w/kg category discussions go back many years at this stage. An endless cycle of the same points.

Hopefully, the results based system will finally do away with these issues.

Looking forward to public testing.

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