Zwift’s physics model includes varied rolling resistance of virtual wheels across different surfaces, so racers should think strategically when choosing frames and wheels for unpaved or mixed-surface routes like Road to Ruins and Two Village Loop.
Here’s a complete rundown of all the rolling resistance numbers and resulting wattage effects for Zwift wheelsets.
(Note: we update this page as new wheelsets are released and surface rolling resistances are changed. See the changelog at the bottom for a running list of changes.)
Zwift’s Road Surfaces
Zwift worlds use several different road surfaces. Here’s the complete list from fastest to slowest:
- Pavement
- Sand (introduced in the Urukazi expansion of Makuri Islands)
- Brick (example: part of downtown Innsbruck just before the Leg Snapper)
- Cobbles (example: Italian Villas)
- Wood (examples: Watopia fishing village piers and bridges)
- Ice/Snow (found only on the Radio Tower climb, as far as we know)
- Gravel (found only on the Sgurr Summit North in Scotland)
- Dirt (examples: Mayan Jungle, Makuri’s Temple KOM)
- Grass (found only on Repack Ridge, as far as we know)
Zwift has built the game so each wheelset can have its own Crr (rolling resistance) value for each road surface type. So a set of road wheels may roll quite fast on pavement, but not be optimal on dirt. Just like you’d expect outside.
When Crr increases, two things happen in game: your speed drops, and resistance increases on your smart trainer.
Zwift Wheel Categories
There are three categories of wheelsets in Zwift, in terms of Crr:
- Gravel: includes the “Zwift Gravel” wheelset plus some name-brand wheels. All gravel wheels perform the same on Zwift.
- Mountain: includes only the “Zwift Mountain” wheelset
- Road: includes all other wheelsets (48 at the time of this posting)
See the full list of Zwift wheelsets >
Each category above has its own Crr value for each surface in Zwift, so each category of wheel performs differently across different surfaces. All wheels within a given category have the same Crr values.
Example: On pavement, Road wheels have a Crr of .004 while Gravel wheels have a Crr of .008 and Mountain wheels have a Crr of .009. This means that, on pavement, Mountain wheels will roll slower than Gravel wheels which roll slower than Road wheels.
Wheelset Crr Values
Here are the current Crr values for each wheelset category on each surface type in Zwift. I’ve included green and red text to indicate how these values shifted when Zwift modified bike performance in mid-2025.
| Surface | Road Crr | Gravel Crr | MTB Crr |
|---|---|---|---|
| Brick | .0055 | .008 | .009 |
| Cobbles | .0065 (+.001) | .008 | .009 |
| Dirt | .016 | .009 (-.003) | .01 |
| Grass | .025 | .016 | .014 (-.028) |
| Gravel | .012 | .006 (-.003) | .014 (+.005) |
| Ice/Snow | .0055 (-.002) | .006 (-.012) | .014 |
| Pavement | .004 | .008 | .009 |
| Sand | .004 | .008 | .009 |
| Wood | .0065 | .008 | .009 |
You can see why pavement feels tougher on a gravel bike than on a road bike. Because it is! The rolling resistance is doubled!
It’s also worth noting that the Crr value for road tires on pavement (.004) is quite low. We’re virtually rolling quality tires on fresh tarmac. Living the dream!
Wheelset Wattage
If you know the Crr value of a particular tire/wheel, you can extrapolate the wattage required to overcome the rolling resistance at a particular speed. This is commonly done outdoors, and in our tests, it seems to work with Zwift’s physics as well (nice work, Zwift programmers).
Doing this shows how much of our power goes toward overcoming rolling resistance. In turn, this tells us how many watts we can save just by moving to a wheelset with lower rolling resistance.
Here are those values, assuming a 75kg rider on a 7kg bike traveling at 40kmh (24.9mph).
| Surface | Road | Gravel | MTB |
|---|---|---|---|
| Brick | 49 | 72 | 80 |
| Cobbles | 58 | 72 | 80 |
| Dirt | 143 | 80 | 89 |
| Grass | 223 | 153 | 125 |
| Gravel | 107 | 54 | 125 |
| Ice/Snow | 49 | 54 | 125 |
| Pavement | 36 | 72 | 80 |
| Sand | 36 | 72 | 80 |
| Wood | 58 | 72 | 80 |
Now things are getting interesting. So if you’re in a race on Watopia tarmac traveling at 40kmh, and you’re on a road bike while the guy next to you is on a gravel bike, he has to put out 72-36=36 watts more than you just to overcome rolling resistance.
But if we move to the Jungle Circuit, suddenly that gravel rider has the advantage, able to keep up with you while doing 143-80=63 fewer watts!
Note: the wattage numbers in these examples don’t take into account additional differences that could occur based on varying rider weights, heights, drafting status, bike frame used, wheelset weight or aero capabilities, etc.
Fighting the Resistance
Of course, rolling resistance isn’t the only thing you’re feeling on your smart trainer, nor the only force slowing your avatar in game. In fact, it’s typically the least of the three factors that determine overall trainer resistance. Just like outdoors, we know that wind resistance and/or gravitational force are usually the biggest things slowing us down.
Changelog
- Jan 13, 2026: updated Crr and Wattage table to reflect Zwift’s tweaked numbers from their sweeping March 2025 Drop Shop performance update.
- Nov 9, 2023: updated dirt (and a few other) surface numbers based on Zwift’s v1.52 update. Also updated to mention that all gravel wheels now perform the same on Zwift.
- Oct 26, 2023: updated gravel surface numbers based on Zwift’s v1.51 update
- Jan 31, 2023: added data for Scotland’s new gravel surface
- Nov 10, 2022: added sand surface data, and explained how newer namebrand gravel wheels have a different Crr than Zwift’s original gravel wheels
- Dec 8, 2019: added gravel wheelset numbers to the tables
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