October 1 update: rolling resistance change for gravel roads?

Did something change in the last Zwift update with regard to rolling resistance on gravel (for specific wheels/frames/combinations)?
I did the DBR Wednesday Race last night B CAT (https://www.zwiftpower.com/events.php?zid=226572) and on the gravel part (road to ruins) some riders had a massive advantage on the downhill part. In no time a break away had a 2+ minute gap and almost 3 minutes at the finish line. Looking to the power figures, mine were similar or even better to the ones of the front group, so it was not just them riding very fast/hard…

Yes, if you look at the release notes you will see that this is the case

Various wheels and tires now have different rolling resistance based on the surface they are rolling on. IE, a mountain bike or gravel tire may be the best on the Jungle circuit, while a road/TT bike is fastest on the tarmac. More to come here in a future update.

but this will have huge impact on road races…can’t this be turned-off for those?

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That I do not know, and you would have to ask Zwift.
However, how is this different to any real road race where people have different equipment? Choose your equipment for the road you are racing on.

I agree Steven, but on some tracks (like Road to Ruins) you are racing on different surfaces, both tarmac and gravel…Still in the race I’m referring to, some would have an advantage on the gravel roads, but others would have this on tarmac…but that was not the case during this races, and that makes it weird :wink:

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Actually the idea is cool, but is there a list of what is gravel tyres? :grin:

There aren’t even tyre choices in the game. There are wheels, sure, but those shouldn’t dictate tyres.

(Unless a tyre choice update snuck in and I haven’t noticed - it’s a while since I went into the garage.)

Could it be that the mountain bike has mountain bike tires and all the other bikes in game now, road bikes, have road bike tires? So the mountain bike won’t perform as well on the road as road bikes?

And in a future update there may be gravel bikes, or an option to select gravel-oriented tires?

That wouldn’t account for the behaviour cited above, where some people had an advantage on Road to Ruins, would it? I mean, I’m assuming that no one was riding the mountain bike in that race, but maybe they were and those people had the advantage.

I could read that the rider in the front group who made a huge break with lower w/kg was riding 454 wheels, most of the others where on tronbike, so that wheels set was way quicker than tronbike, there must be other wheels to, there must be a list, or then zwift insider maybe know what they should test next:) just the jungle time he made a 1,5 min break from a group hammering higher watt/kg numbers out. On twitch m_nim was streaming there you can see what was going on if you are interested;-)

Having done 294 races (according to ZP) i have seen a bit of racing on Zwift. And what i experienced yesterday was absolutly not normal at all.


I was not in the race, but organize it. Since we have a team racing, then I was following it, both live and via a few streams. The race was Road to Ruins
What we (all) noticed was not right. People on Zipp 454s were extremely quick on gravel, but slow on tarmac. Tron Bikes the opposite. The guy using the 454s (and a Giant propel) managed to pull out a 5 sec gap at the top of the hill just before the jungle. He increased that solo to over 1:30 on the gravel section, putting out about the same power as the chasing pack of 15. Once they hit the tarmac he was pulled back by the people on Trons.
The race had categories start a minute apart, A’s going first. There ware C riders catching up to and riding past B’s at ridiculous speeds.
It ruined the race for most. We are debating rescheduling our events, that has any gravel sections… but then again… seemed like tarmac was equally bad for others.
This is something that needs to be addressed.

I know exactly what you are referring to.
Even with different rolling resistances, a single rider should not be able to hold off a chasing pack, that are putting out same or higher power than him.

I experienced the same for yesterday’s Jungle Circuit Race, was getting passed by many single riders doing 2.5w/kg while I was putting out 3.7-4.0, couldn’t even sprint to catch them as they flew by. These results show the issue:
https://zwiftpower.com/events.php?zid=226602 (specifically the times and powers for the C group are most obviously strange)
In the Bs the 1st and 2nd place had a massive time gap for the same or less power than the 3rd and 4th finishers, they just seemed to take off unrealistically fast once we hit the off road section never seen anything like this, nearly quit due to this
I didn’t notice what wheels everyone was using, I was on the Meilenstein’s


I think the issue is down to different clients not being updated. If you were on iOS, where the update is not enforced, then you would not experience the impact of being slower on gravel.

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Similar to the above experiences, I just watched a race on the Jungle circuit where riders doing 3W/kg were passing riders doing 4.5W/kg. The ZP numbers back up my observations.


I know my comments are supposed to be constructive, but come on Zwift, this is a gong show!

Those are probably people that did not update Zwift to the latest version. Not a lot that Zwift can do about it. for some reason the ATV does not always update.

I heard back from support.

This feature is intentional as others have described above. Different rolling resistances on different road surfaces. Older clients apps have an advantage over up-to-date clients.

The tuning seems completely wrong to me. We are talking about a 1-2watt/kg penalty at race speed for riding on the jungle circuit using the new app vs. the old app.

Here is a Youtube video from a race yesterday:

In 90 seconds, you can witness what everyone above is talking about. Two C riders passing an A+ rider who has to output 600 watts just to get into their draft, which he is unable to hold

My advice for now would be:
-avoid any races with extended gravel sections
-plan to sprint through any shorter gravel sections, just like going over the top of a climb
-hit the vote button above so that the Zwift devs notice this thread and detune this change

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I really think the new addition will be interesting. The big problem we have now is people running on different versions of the app.

The different versions is one thing, but it also appears that the WKG required on some roads might be way out of whack. Needing that sort of WKG to keep up, on a downhill, just seems a bit crazy. I did a 3 WKG ride yesterday that I had not had any issues with in the past, but I was regularly over that yesterday just to try to stay with the pack. It was not a good experience and I ended up just leaving the ride early. If nothing else, I’d at least like to see Zwift proactively give some idea of which tires (ok, wheels) are best on which type of road. I don’t have to guess at the bike shop, so why isn’t Zwift being more forthcoming, especially with a change that seems to be having an ill-received welcome?

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