Why does Zwift use W/KG for flat races?

I am really light (60kg) with an ftp of just 208.
Now according to my w/KG and zwiftpower i am forced to race in the B Cat.
I like the flatter races, but my ftp is just good enough to maybe hang back in the C Cat. So far this is really holding me back from racing on Zwift.

I see that the average ftp for B is around 270, I am nowhere near that and will never be able to stay in the group.
Even if I get better (250ftp) to maybe be middle pack I would be bumped to A which will put me in the back again.

I really feel that as a lighter cyclist the system gives me no chance of being competitive.

You could argue that a lighter cyclist should specialize in climbing, but I would only be average as I am competing against riders with the same w/kg.

The system gives a disadvantage for me in flat races and no advantage in hills/mountains.

IRL at least lighter riders can draft better because of their small size, but I dont think Zwift has something like that.

Long rant I am sorry for that, but wouldn’t it be better to assign cat for flat races based on ftp and hill/mountain races w/kg

Or even better, based on past results

I think they are working on an alternative race ranking system. Not sure of the details though.

1 Like

Haven’t heard anything about this, are you sure?
Anyone else knows something about this?

No, but one can hope so.

w/kg was used by the community long before there was racing or even starting pens in Zwift. As Zwift grow so will racing.

w/kg was just a way to group similar riders together, but that only hold true for routs with climbs.

Yes Zwift does take your length into account and it calculate your drag using your length.

But lighter/less strong riders gets dropped on the flats even IRL.

No road is perfectly flat, you just need to learn how to use your weight to your advantage.

Hi Gerrie,
not that I know much about racing IRL, but could you use the real cycling Cat
system whereby you work your way through the Cat’s, starting at the bottom,
and progressing through them as you improve.
I’m not saying that all Zwifters should have to do that as there are obviously
some Zwifters who are Semi-pro or Pro, but I for one would be happy to start
at the bottom and if possible work my way up (or just stay at the bottom LOL).

“Ride On”


I am fairly certain that Mayfield or someone else discussed it either on a podcast in the last few months, or on the forums in a post. I recall that it was was acknowledged that the current w/kg system is imperfect and that they had some ideas. It may have been talked about in a discussion about group rides and advertised w/kg, or probably a podcast interview. I also remember that they had been working with the people at zwift power learning from the data so that maybe we will get something similar to the categories everyone is familiar with in real life by working ones way up. Not sure though.


Using my weight in my advantage Sounds good, but i am only average in w/KG so on the hills i can maybe hang on.
But do you really think i can race people with an 280ftp vs my 200ftp?
I will get dropped on all flat sections and will never back, I am not stronger on the hills either.

Yeah i would be dropped by them irl as well because they are much stronger. The point is that I should not be racing them. They are much better cyclists.

I am just an average once in a week casual rider who has to ride B class. Totally ludacris if you ask me.
I will get destroyed all the time.

Edit: Sorry not against you gerrie now that I read correctly. You seem to agree that the system is flawed.

1 Like

That is what I hope Zwift is working towards. It will be awesome.

I remember something like this, but I imagine it is not top priority. It will be nice thou.

I hope at some point there will be a ranking system. Are you a B rider on Zwift Power? The more you race the stronger you get. Try some different races some are harder than others.

1 Like

Yeah I am B on Zwiftpower. My watts are exactly 200 there so I am B by just 1W, as i recall 200w is the limit to get B.
I will try and be honest to start in the right category, but I feel like an out of place tour rider.

Yeah for sure. Participating in racing isn’t as fun when half your opponents are in the wrong category.


That get me all worked up… Why o why. That is why my number one request is to please auto categorize riders. There I said it again. LOL

Please vote!