Zwift released its first gravel bikes in their December 2019 game update. The Cervelo Aspero, Canyon Grail, Canyon Inflite (actually a cross bike), and Zwift Gravel were built in game similar to how they’re built outdoors: to perform well on dirt while also zipping along nicely on pavement. Later, the Lauf True Grit and others were added to the list.
But how do they actually perform in game, and how do they compare to Zwift’s mountain bikes and the established crop of road rigs?
We ran extensive tests to find out. Here are the results.
Flat Pavement Performance
Here’s how each of the new gravel bikes performed over two laps of our Tempus Fugit test segment (300 watts steady, 75kg rider):
- Cervelo Aspero: 53:47
- Canyon Grail: 53:49
- Specialized Crux: 53:50.5
- Giant Revolt Advanced Pro, Liv Devote Advanced Pro: 53:51
- Allied Able: 53:51.5
- Canyon Inflite: 53:53
- Specialized Diverge: 53:53.5
- Zwift Gravel: 53:54
- Lauf True Grit: 53:57
The Aspero wins this contest, with the Grail close on its heels.
The fastest road bikes complete the test route in 50:17, while the slowest road bikes (Zwift Steel with 32mm carbon wheels) complete it in 51:40. Clearly, gravel rigs perform quite poorly on pavement.
The fastest mountain bikes complete the test route in 55:40, meaning the gravel rigs are turning in times right in between the fast road bikes and the slower MTB.
Hands-On Experience
I found the gravel rigs to be quite challenging on pavement. I had to hold ~30 more watts than those around me just to hang with the group on the flats, turning a “2.0-2.5 w/kg spin” into something a bit more tougher.
Climb Performance
Here’s how the new gravel bikes performed up the big Alpe du Zwift climb:
- Specialized Crux: 51:18
- Canyon Grail: 51:25
- Allied Able: 51:35
- Cervelo Aspero: 51:39
- Giant Revolt Advanced Pro, Liv Devote Advanced Pro: 51:42
- Specialized Diverge: 51:51
- Canyon Inflite: 51:55
- Zwift Gravel: 51:56
- Lauf True Grit: 51:58
The super-light Crux wins the climbing contest quite handily, with the Grail 7 seconds behind.
The fastest road bikes climb the Alpe in 48:50, while the slower (Zwift Steel with 32mm carbon wheels) complete it in 49:55. We already know the gravel bikes are slower on flat pavement, so this is not surprising.
The fastest mountain bikes climb the Alpe in 55:21. The mountain bikes are quite heavy, so this isn’t surprising, either. Like our flat tests, the gravel bikes sit squarely in between the road bikes and mountain bikes in terms of time up the Alpe.
Jungle Performance
Here’s how the gravel bikes perform on one lap of the Jungle Circuit using the basic Zwift gravel wheels (keep in mind the new gravel wheels are faster on dirt than the Zwift Gravel wheels):
- Specialized Crux: 14:10
- Canyon Grail: 14:11
- Cervelo Aspero, Allied Able, Giant Revolt Advanced Pro, Liv Devote Advanced Pro: 14:12
- Specialized Diverge: 14:13.5
- Canyon Inflite, Zwift Gravel: 14:14
- Lauf True Grit: 14:15
The Crux just barely edges out the Grail, which just barely edges out the Aspero. But the Aspero is close behind.
The faster road bikes complete a jungle lap in around 15 minutes flat. Zwift’s new gravel wheels drop lap times for gravel bikes to 13:56 thanks to their lower Crr, so if you extrapolate that difference out over 4 laps we’ve got a difference of over 4 minutes between the road bikes and gravel bikes. Finally, the gravel bikes get to show off a bit!
Hands-On Experience
My gravel rig destroyed the road bikes on the Jungle Circuit. While the road bikes labored at 2.5-3 w/kg up the jungle climbs, I chugged along at 2-2.5, holding ~40 watts less but still dropping the pack of road riders.
Gravel Conclusions
The Specialized Crux is definitely the bike to have when it comes to gravel climbs, while the Cervelo Aspero is a better performer on flats and descents. The Grail is somewhere in between, being a bit more aero than the Crux and a bit lighter than the Aspero. Choose accordingly.
Don’t Use Stock Gravel Wheels
If you’re going to use a gravel bike, don’t use the stock Zwift Gravel wheelset. Instead, use one of the name-brand gravel wheelsets in game, because they roll faster on dirt due to lower Crr, trimming ~17s off of one Jungle Circuit lap (and much more time off of the Makuri Islands Temple KOM).
Your Thoughts
Have you tried out the new gravel rigs in Zwift? What did you think? Share below!
Always great work. Appreciate your research!
Great stuff again Eric.
Went round the Jungle the other day n used my Cervelo S5 to get to it, then changed to the Zwift Mountain bike n zoomed around the course much quicker than all the other bikes.
Caught a bloke for 1 min 20 secs on just the climb from the bottom up to the bridge at virtually the same wkg.
Left a large group ride of tt bikes literally in the dirt. 😋
Eric, so which MTB is the fastest in the jungle?
Got a post coming out tomorrow about it, but basically all three are very similar. Pick the Scott or Specialized for the absolute best performance.
Thanks for testing this! Are the gravel bike times on pavement roughly accurate in the real world? If so, what is it about gravel bikes that causes that much slowdown over even the slowest road bike?
Hard to say if they’re accurate or not. Gravel bikes are slower than road bikes IRL because 1) you ride with a more upright stance and 2) you run bigger, knobbier tires.
Just HOW less aero you are, and what sort of tires you run, will determine how big the gap is. I have friends who ride pretty aggressive gravel bikes with fairly un-aggressive tires, and they can keep up with us on hard road rides. Zwift’s gravel bikes, I would say, don’t perform as well as these friends’ bikes, on the pavement. 🙂
Slower than road bikes on tarmac, slower than the MTBs on gravel. Perhaps on a 50/50 course (half tarmac half gravel) they might make sense but then switching bikes (going from road to MTB) half way through might be faster still.
Road riding, virtually speaking, makes a lot of sense for training. The trainer a person is using is smooth, the road is smooth and so forth; it fits nicely. Gravel and mountain bikes are taking the idea too far. What’s the point? One can’t feel the bumps, jarring handlebars, the sliding of the tires in loose sections and so forth. The gravel “fad” in RL doesn’t translate into a virtual world well at all. Don’t even get me started on steering. Dumbest idea ever. Then, the rocket scientists at Zwift take sections we’ve all ridden for over a year, know… Read more »
@FL_Roadie – Wow that’s quite the rant! While I do agree on the constant “gamification” of things being a bit much for my tastes, I think that the majority market that Zwift are targeting probably do appreciate this more. Zwift, at the end of the day, is a game, rather than a 100% serious training tool. Virtual bunchies, races, chasing other riders up virtual climbs, etc. It’s all good fun. The changing weather and seeing different bikes / kit keeps the visuals interesting. I won’t be spending my Drops to add gravel or mountain bikes to my virtual fleet, but I’m… Read more »
You echo my feelings precisely
Virtual gravel is silly, I have to agree. Waste of effort on the part of the designers and devs, and has had the effect of reducing good available routes. Making this change so late in the development of the platform was a poor decision, and more expansion effort on gravel will be of limited value. Too bad. IRL gravel riding, sure, I can see the appeal. The only effects in Zwift are to add resistance, break PRs, unnecessarily (and not interestingly) complicate bike choice, and reduce the number of good ridable roads. Virtual weather doesn’t slow us down, so I’m… Read more »
There are trainers out there now that can give you the feeling of riding on dirt or cobbles. I don’t see any reason why anyone is complaining about having a virtual dirt road to ride on, or having weather changes. This is all built to help offset the eternal boredom of just plopping your self on a trainer and sweating for an hour. I personally like everything they are doing, it provides lots of distractions.
Don’t mind the visuals and equipment, but adding to the effort on mainline routes (ocean blvd, etc) means it’s not just a pleasant addition.
Consider moving these sections to a distinct world, or to non-through roads so that they’re available to those with an interest but not negatively impacting everyone.
Gamification is fine, but someone needs to keep an eye on quality game design.
@tempo, Mike and Ernie, After I typed out my borderline rant, I was further thinking about the weather issue. I could imagine seeing a building thunderstorm on the horizon with flashes of lightning across the sky and perhaps hear the thunder etc. Now that would be neat to see; yet another form of eye candy to watch while one is suffering lol. I’m opposed to getting rained on, a personal bias, because I live in Florida. Yeah, we get a lot down here, but I have lived in a desert and once it didn’t rain for 9 months. When it… Read more »
I see the gravel bikes as a way of fine-tuning my group ride effort – If I want something slightly harder than the advertised pace, take a gravel bike. Going somewhere flat – take a gravel bike.
The extra resistance blows groups apart. That’s what has to be addressed (ability for riders to turn it off perhaps) or we’ll stop using places like the jungle which would be a shame as that’s my favourite route.
As others have said – training platform first, game second.
Game first, training platform second. It’s in thir logo – fun is fast. If you want training use TR.
You have to come to a complete stop to switch bikes or wheels… So you will lose whatever gain you get by switching… and if you lose the group you were with… well.. your toast
I bought an Aspero and promptly got smoked by a mountain biker in the jungle. Grrr. I should’ve been satisfied with the Zwift Mtn bike for now. Also – will any gravel specific wheel sets become available?
Yeah, I can’t think of a single person who likes the fact that the jungle route basically sucks now. I used to love this route for solo riding and training, nice variation of easy rollers and good visuals. Now it’s basically useless, I won’t ride there and avoid any races on it. Which is a shame, because races on that route is a great workout. Agree they can have the gravel and mtb stuff, but make it separate courses from the road stuff, and get rid of this nonsense where the dirt and gravel parts are now slow. I think… Read more »
I fail to see how being slowed down (compared to a virtual reference on top of that) would have any impact on solo riding or training. As for races, everyone is facing the same conditions.
I’m curious if they have data on how many users choose the jungle route. I would imagine the numbers have plummetted with the physics change. I stopped riding it after my first ride through with the new physics. It’s a shame as it was one of my favorite routes.
Does it make a difference if you have road bike wheels on a gravel bike? I did round 1 of the Cervélo Gravel Rush Series today. The bike was automatically chosen as a Cervélo Aspero but it was wearing the Zipp wheels that my normal road bike wears.
Yes, it would make a difference, because road wheels roll differently than gravel (https://zwiftinsider.com/crr/)
That’s really odd that you had your Zipp wheels on the Aspero – that shouldn’t be possible, as far as I know! When I switch to the Aspero, it puts the gravel wheels on it and I can’t switch them out.
Thanks for a great article. I do love my gravel bike in real life. On Zwift, just it seems that a gravel bike is never the “best” option for any course or race. This is probably because Zwift can’t quite replicate the punishment and misery of taking my road bike down a sandy dirt road.
pretty sure there is plenty of misery in taking a road bike on jungle circuit.
Really useful thank you. Still struggling to see the point in gravel at all in ZWIFT at the moment. There is hardly any of it so racing on it is repetitive/boring with just the Jungle loop as an option. With key routes coming off the jungle route it is quite frankly a PITA. Either expand it and keep it away from key routes or get rid of it 🙂 Anyway that’s me vented for another week. Keep up the good work.
I put a feature request to liberate the dirt roads in France. The gravel bikes desperately need a playground on which they excel.
I think Zwift needs to improve its steering. As it stands, its almost impossible to weave my way around all the roadies floundering on the dirt.
So confusing. I did the new Mayan figure 8. I picked the SWorks Roubiax bike and tubeless wheels. I smoked it wicked fast. But each gradient feels 2%+ harder, but you don’t get credit for climbed altitude. I’ve ridden the old jungle on Scott MTB but Roubiax feels quicker. Maybe time to revisit all the numbers. Clearly it’s frame plus tires for best formula. It’s a great route for change up, stunning graphics but not easy and most people not regulars there.
What wheelset would you recommend for gravel rides – keeping same bike
All gravel bikes use the same gravel wheels. You can’t change them at this time.
Does anyone know which bike, MTB or gravel bike, is the fastest on serpentine 8? Cause there’s also a lot of solid ground I think.
Thanks a lot!
According to Eric’s comment on this article https://zwiftinsider.com/route/serpentine-8/, “There’s still too much dirt for the gravel or road bikes to win here. MTB still wins, hands-down!”
love the gravel and the fun of changing bikes for different terrain
I have a grail, which I love and which I use on my smart trainer for Zwift. Having a virtual one to match it will make me smile every time I log on to workout. There’s more to life than going slightly faster than a stranger in a virtual world.
OK here’s a question (well two), does a gravel bike draft faster than a MTB? So will it be faster in race conditions? And is it faster on the new Serpentine 8 route with more non-gravel sections?
According to Eric’s comment on this article https://zwiftinsider.com/route/serpentine-8/, “There’s still too much dirt for the gravel or road bikes to win here. MTB still wins, hands-down!”
With the release of Yumezi I’ve come back to check out the gravel bikes as it’s looking like this is where they could actually have some use – that Canyon Grail suddenly looks appealing from the first impressions of the routes. Will be interesting if some testing is done to compare 🙂
Eric’s great analysis on bike choice for Makuri Island routes (https://zwiftinsider.com/yumezi-bike-choice/) reveal that this is where gravel bikes shine. I’d say comparing gravel bikes in that environment makes sense. Comparing these five (and future) gravel bikes on Kappa Quest and Temple KOM would be more interesting than Tempus Fugit and Alpe du Zwift.
My guess is Canyon Grail would excel on the Temple KOM, but the Aspero might get close on the complete route.
Could you pls revisit this investigation and test performance on the Markuri island map?
Unlike other commenters I really appreciate the variables, for me Zwift is not just for training but for fun too! It is a shame the Lauf fares so poorly in the head to heads – while it may be slightly heavier/less aero than the Grail and the Aspero, it should make up for that in its superior off-road capabilities (e.g. perform closer to a MTB in the jungle routes).
Hope Zwift will take this into account in a future update, as I love the bike (and imagining I own one)!!
Hi Eric.
I assume that the biggest variable is the wheels not the frame. All gravel / mountain use a standard wheel. But I have never seen Zwift road wheels tested side by side on gravel. Surely they must all have different rolling resistant and therefore create differences.
can you speed test wheels on gravel please?
All road wheels have the same Crr on various surfaces. On Zwift there are just MTB, gravel. And road wheels. See https://zwiftinsider.com/crr
Hi Eric, did you ever test the Tron vs Road-Wheels on dirt ? Dan Diesel looks faster than roadies every time when it comes to dirt after the water tunnel. So, do you have a Tron test time for the Jungle Circuit or a roadie test time in Makuri with the Temple KOM included where the Tron climbs 7:36 and the route in ~17min ?
Hi Carsten – yes, I’ve tested the Tron vs road bikes on dirt. They all roll at the same Crr… no difference.
MTB may be fastest in the jungle on TT, but not necessarily in a race. Just lost in the Jungle to a rider on a Canyon Grail while I was on the Trek MTB (forget which model). Because of race tactics / game theory, the front B group was only pushing about 3.6 W/kg for 4 laps. The Grail rider just stayed in the draft and averaged 3.6 W/kg to stay with the group as well. BUT, the final sprint has a section of wood boarded bridge followed by pavement followed by dirt and I noticed early in the race… Read more »
It will be very interesting to see how this pans out in this weekend’s Stage 4 of the TDZ.
I came here to figure out which bike I should use for a certain ride, but then I realized that I just don’t have any interest in maintaining a virtual garage.
Think the best use of a gravel bike currently is to adjust the wattage needed to hang with the pace partners or if you are in a meet up with a buddy.
Is there a list of routes with a gravel or mountain bike advantage? or just Jungle route and Serpentine 8?
Some routes on makuri islands are gravel advantage: kappa quest in either direction and spirit forest.
Thanks for updating this with the new bike.
Very important question: does the Crux get a color-slider?
It does not. #sad
Why test gravel and mtn climbing on AdZ versus doing Kappa Quest or reverse Kappa Quest?
He tests those too: https://zwiftinsider.com/yumezi-bike-choice/
But it’s good to have one reference test where you can compare every bike.
The table shows that the Crux is the clear winner, but the text says the Aspero is faster on the flats. So, which is it?
As the post says, “The Specialized Crux is definitely the bike to have when it comes to gravel climbs, while the Cervelo Aspero is a better performer on flats and descents.”
So it depends on the course, which one is better.
Any more details on the respective Crr values for the name-brand gravel wheels? Or any other stats for how each of them perform in comparison to the stock Zwift set?