Yesterday I rode (raced?) the long-distance version of Tour de Zwift‘s stage 3 group ride.
This was one lap of Watopia’s Big Loop which begins in downtown Watopia then travels over the Epic KOM to the Jungle Circuit before returning to downtown by way of a ride around the volcano. With the Epic KOM included I knew I wasn’t going to finish in the front group–but I knew it would be a great workout anyway, plus I was anxious to try an experiment… for science!
The Big Question
Before the ride began I knew I would be swapping from my road bike (Specialized S-Works Venge with Zipp 858 wheels) to a mountain bike (Specialized Epic) for the Jungle Circuit portion of the route. Some Zwifters aren’t fans of the swapping idea, but I think that’s just because they haven’t tried it. 😄 I find it’s a fun challenge to swap bikes as quickly as possible, then work to pass other riders in the Jungle while I have a speed advantage before swapping back to the road bike.
But the bigger reason for my swapping was a desire to test a theory. This ride would answer the question: how well does the MTB perform against packs of roadies in double draft mode?
If you recall, I first wrote about how well the MTB swap worked in my post about the Le Col Metric Century. But that ride used Zwift’s standard draft, not double draft. With the draft effect being doubled I was sure the MTB would offer less advantage since the packs of roadies would be moving faster. But would the swap strategy still prove valuable? There was only one way to find out!
The Swap, Part 1: Losing
As we hit the Jungle dirt I was in a pack of ~15 riders, putting me somewhere between 134th to 169th place overall in the field of 689. (This is an important number to look at before you swap bikes, because the goal, obviously, is to move up in the placings by the time you’re back on your rode bike after completing the Jungle Circuit on the MTB.)
My bike swap was pretty fast, but still by the time I was back up and riding my group was 10 seconds up the road. Now the fun began–how many riders could I catch?
The first portion of the Jungle Circuit is a descent to the lap banner. Here I noticed that, unlike previous swaps, I wasn’t gaining time on the group I was chasing. They stayed 10s-11s ahead during the entire descent. Double draft was definitely working in their favor.
Then it got really ugly at the bottom as we hit the wooden boards/bridges on either side of the lap banner. I had enjoyed a rolling resistance advantage in the dirt up to this point–my Crr was .014 vs the road bikes’ Crr of .025. That’s a big difference – nearly 100 watts at 40kph!
But on wood, the Crr of a road bike is .0065 (nearly the same as pavement) while for MTB wheels it is .01 (see more on specific Zwift Crr values here). That’s a ~40 watt disadvantage at 40kph. Plus they were working together in double draft mode, while I was soloing!
There are also some “hardpack dirt” sections on either side of the wood which look like the dirt around the volcano. It’s noticeably different from the Jungle dirt (it rolls fast, and no dust is kicked up). This surface has the same Crr as pavement, meaning I was at a 60-watt disadvantage here. Ouch.
Thanks to the wood and hardpack sections at the bottom of the Jungle I lost another 10 seconds on the group I was chasing, putting me about 20 seconds behind as we began climbing up and out.
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The Swap, Part 2: Winning
As speeds slowed from ~40kph on the descent and flat to ~20kph on the climb, I knew the double draft advantage was mostly gone since air resistance isn’t much of a factor at slow speeds. If I was going to catch that group, it had to happen here!
I kept my watts steady and saw the time gap steadily drop. I passed a few stragglers, then caught the group I’d been chasing as we neared the rope bridge at the top of the Jungle Circuit.
I stayed on the MTB until the dirt ended. That’s where I made the swap back to my road rig, put in a good dig for about 20 seconds to catch the group up ahead, then assessed the swap situation.
Was it worth it?
I don’t think it was. Not today. The group I rode out of the Jungle with was basically the same group I started with–the front place in the finishing group was 137th overall (it was 134th when we entered the Jungle).
It’s possible that the roadie group was working significantly harder than I during the Jungle portion, but based on the effort level I saw from them for the remainder of the ride, I don’t think that was the case.
I think double draft, combined with the Crr disparity at the bottom of the Jungle, made the swap strategy a wash in this ride.
Roving Gangs of Hairy-Legged MTBers
Here’s how the MTB swap could still work well in a double draft race: if several riders all swapped to the MTB then rode together, taking advantage of the double draft.
There would still be a slight disadvantage at the bottom of the Jungle through the wood sections, but the MTB gang would certainly gain time on all the dirt sections, especially the higher-speed descent where double draft matters most.
What About You?
Have you tried the swap in a double draft event in the Jungle? What is worth it? Share your experience below!
I did the swap, but only starting at the climb out of the jungle section – no Crr losses, all gains. made 25 places (105 to 80) and then dropped 5 back swapping back to the road bike but caught that group on the climb back out of the section. The double draft certainly seems to overcome any descending advantage.
Smart move.
Interesting. I wonder if matters which MTB you’re on. Before the swap, I was with a group of about 5 riders. Then, I got on a specialized epic and caught them by the bottom of the descent. I could have been hammering much harder though – hard to tell.
I tried this is the group ride for Stage 3. Mostly to attempt to save my legs for later in the race
Eric I did change went from 420 to 315 in same event thou there was 1500 people in my wave
In Mondays tour de zwift I changed to the canyon grail thinking it would be faster than the mtb, am I right or should I have chosen a mtb? I did seem to make some places up but it was hard to tell as my changes weren’t great.
Mike
Although it feels like the Grail should be faster than a MTB on the Jungle roads, the MTB is actually faster by 15-20s! See more at https://zwiftinsider.com/gravel-bike-results/
I did swap yesterday. Far back in group. Went from 775 at pavement end changing to dirt to 803 on switch (from Tron to mtb)…within 3 min, had made back to 775 and finished loop 153 positions ahead (lost 8 places on switch, the 153 is net). BUT, picked off small groups of 4-10, not huge groups getting DD. Plus, that far back, may not have super strong efforts. Anyway, well worth swirch
Interesting!
Hello Eric, Hello All,
I will be doing the Stage 3 Long distance on Thursday. I was thinking of using the Canyon Grail gravel bike for the Jungle portion.
Based on your conclusions here about the MTB swap and what others are saying about swapping on the climb out portion of the Jungle, I believe my strategy would now be to swap for the gravel bike at any opportunity between the beginning of the Jungle circuit and the climb out portion. By opportunity I mean doing the swap only if I am not drafting in a large group or at least 10 seconds ahead of a group, so I can avoid losing the double-draft or gain double-draft advantage following the swap… Good timing is essential here I believe… It’s either work hard to distance the group prior to the swap… Or work hard catching them after the swap… unless there’s another group behind… It will all depend on opportunity and a bit of intuition here…
Anyone has tried a gravel bike for the jungle circuit of Stage 3?
What are your conclusions?
Did you swap back to the Road bike or did you keep the Gravel bike to finish the stage?
I found that the MTB did give me a advantage. I was approx 225 position. Took a few extra seconds to make the bike swap to MTB. By the time I made the switch to MTB and back to full pace, the group i was riding with was 23 seconds ahead. I stuck with my watts around 250 (which felt noticeably easier in the dirt with MTB!) started picking off stragglers. Was gaining ground on the pack then hit the wood (Tunnel) and started to lose seconds (I think actually 1-2 seconds) and felt like I had to work harder! Once off the wood and back on the dirt I made up those 20 seconds easily. When I hit the pavement switched to the tron bike and I was approx 30 seconds ahead of the pack. I was able to chase down 4 other small groups along with another (strong) rider) and finished 166 place.
I think the MTB really saved my legs for a strong finish.
I rode my Tron for the start and I did the swap to my Zwift MTB (frames right next to each other in my garage) but didn’t’ have a great strategy for when to swap. I decided to stop pedaling when I hit the first dirt, which means I had to wait and wait as we all kept descending (not smart but I did learn something). Once on my MTB I picked up places easily. I originally started at 760/944 and at the jungle I was at roughly 500. In the jungle I continued to pick up places, roughly 100, and switched back as the dirt turned back to pavement. I finished at 398 per companion app and 239/413 ZP. I actually tried to talk others into swapping with me and had 3 or 4 do it, we all rode together and took turns pulling for each other. I felt it was completely worth the swap and similar to a Jungle length power up.
Nice! Getting others to do it with you would really help speeds on the descent.
Next time, use the brake hack to slow quickly: https://zwiftinsider.com/brake-hack/
Also did the bike swap, but for me didn’t work out this time. A few weeks back during the Zwift Fondo I gained 20 seconds and about 20 places. Now the bike swap got me in nomansland between two groups. Ended up being picked up by the second group that started the jungle 50 secs behind me. Main difference with Zwift Fondo was that I started out at about 50th position with the groups doing around 3.5 w/kg. Managed to overtake some single riders but was no match for the groups.
It’s easier to swap when using a PC. It takes longer when using apple TV
I made up positions (was 220 before, 198 at finish) doing the swap, even though some groups passed me back before the uphill and looser dirt. I probably worked harder because I was having such fun catching people. Also, I am a slow switcher.
I just did this just today! My first swap was kinda slow and the group I was with went down the road. I too was in about 130th and was able to get back to 130 by the end of the Jungle Circuit. The MTB was fantastic at catching single rider stragglers but I never caught the group I was with even though I made up the lost places. I do think however it did allow me to not work as hard on the Jungle Circuit and still make up a lot of ground on single riders. I only lost 10 seconds and one place on the second switch and was able to make that up.
I was thinking about this last night when I rode Stage 3 of TdZ 2020, in my event we had a gentlemen who rode a MTB for what I was pretty sure was the entire distance! My plan was to use a bike/wheel setup to optimize my effort for the climbs, with the Epic KoM and the climbs into and out of the jungle on the Watopia Big Loop route. I decided on the S-Works Tarmac with the ultra lightweight Meilenstein wheelset, knowing full well that I would be fine climbing, but on rolling or flat terrain I’d have to find a group and stay with them at all costs because my setup was not aero optimized. Anyway, I got into a pretty strong gruppetto – we quickly worked our way well into the top 100 positions, and I saw the MTB guy as we crossed the bridge going up the Epic KoM. That rider really had his work cut out for him on that section, and I wasn’t sure if I’d see him again down the road. But I did, and when we got into the jungle, our gruppetto had definitely been whittled down, the MTB guy had caught up and was really challenging us through the jungle. Definitely strong, I saw his power spike up to 6.0 w/kg when he needed to close gaps. My point is that a really good test would be to have two groups of 10-15 riders, the first one on really good flat-rolling roads setups (the more Tron bikes the better), the other exclusively on MTBs, run a 6 lap race through the jungle with a handicapped start for the MTB group, and see what happens!
i did an inadvertent swap. I had purchased the Canyon Grail the day before i did the ride, and i forgot to switch back to my tron bike before starting. I still passed a ton of people in the jungle, but i didn’t seem to suffer quite as bad on the planks under the waterfall and through the caves. i wasn’t paying close attention to my placements, but i would estimate a gain of 50 or so places.
I swapped to the MTB and made up loads of places. But the time it takes to change bikes is frustrating, ie waiting for my Kickr to spin to a stop before being allowed to change bikes. Is there a quicker way? Pressing the A key doesn’t speed things up.
Would you damage a Kickr by leaning your foot into the flywheel to add friction to stop faster?
@Gary Yngve – you don’t need the flywheel to stop. You just need your power to go to 0, which it will do quickly once you stop pedaling.
Hmmm I did think that… but only just got a replacement Kickr after last one broke 🙁
“A” certainly speeds things up for me on my KICKR. Stop pedaling, press A, wait until your ride stops moving, then hit Esc and T to bring up the Garage.
Eric, is that a press and hold the A key?
Nah, just tap it. Brings up the pairing screen, which auto-brakes you: https://zwiftinsider.com/brake-hack/
Thanks Eric.
Love the Post. I did the same thing but am not nearly as fast of a rider. I’m usually way in the back of the pack. When I did the same stage I was about 1200/1600 heading into the dirt. I did an immediate bike change (to Zwift Gravel, not MTB) and lost about the same 10-15 seconds, but I was able to make it back almost instantly. At the back of the pack speeds are a bit slower anyway and also we were fairly spread out after Epic KOM so I mad up the time in about 2-3 minutes of riding. It was harder to keep up in the cave at around the lap banner but then I continued passing people on the way out finishing with a feather on the rope bridge. By time I switched to my Tarmac I had passed 20-30 people.
I’m usually in the bottom 10-25% percentile on these group rides. I swapped and definitely sniped several positions while on dirt… plus I think it jazzed me up to push myself more as well as part of that challenge.
Definitely worked for me – went from ~290th before my swap to MTB to ~220th after the jungle circuit. It was so much fun zooming past the groups on my fat tyres! 🙂
I was 130ish of 200ish over the top of Epic KOM. I had heard about the bike switch possibility, so at the beginning of the Jungle Section I tried it out. It took about 10-15 sec on and iPad. I was number 90ish over the line. It seems like on the MTB I passed several groups of riders. Even some who had passed me on the KOM. I am not a super rider or anything, but it definitely gave me an edge 🙂
Another advantage (if you, just like me, don’t have a tron bike), also referred to by Ray Morro: you can start with a climbing bike, switch to a MTB before finishing on an aero bike (or vice versa, depending on the route)…
I actually went Aspero all the ride – made up nearly 100 positions (just below 400 to 303) in jungle and didn’t loose any on the 7K to the finish line (thanks to drafting off a roadie). But did have to invest 0.1 – 0.2 W/kg more than the people having comparable finishing times (but I am pretty tall, so 0.1 more effort is not unusual).
Love this column, thanks. I thought about a swap whie riding Stage 3, but we were a good group when hitting the jungle and I decided not to swap. Well, it costs some efforts during this part but was fine for me. But I will really try this in a “t 🙂 raining” ride
Is a bike swap worth it on the Bologna TT course? Cervelo P5 to Trek emonda for example for the final 2km? Does it make more sense in a TT as you don’t suffer loss of draft effect?
Swap won’t help you in Bologna–any gains you would get are well offset by the time taken to do the swap.
I switched from my virtual Madone to the Zwift MTB and gained ~10 places over the jungle section, I was only averaging ~200W.
I hadn’t noticed there was “double draft” in effect, but that could explain why I lost some places on the descent and especially around the wooden flat section. However, the amount of places I made up on the climb to leave the area was insane, something like ~70 or 80 positions… Becoming place neutral less than 30secs from the summit, presumably as road bike riders were either accepting they were going slower for the same power on gravel, or they were recovering a bit from extra effort up the several minutes+ of climb.
It’s all speculative though in my example/experience, it was a “sportive” after all, a few of us text chatted about the switch before and after Jungle… Some said they had a net position loss, but I think most of us had a net gain.
Can’t comment on the double draft but having read previous articles regarding using the MTB, I decided to experiment on yesterday’s stage. Headed into the jungle in a group of 5 riders trying to work out the best time to swap bikes. I waited until the first 3-4% uphill part and having never changed bike mid-ride before, by the time I was pedalling again I had dropped to about 45 seconds behind. I was using the basic Zwift bike and by the time I left the jungle I was well over a minute ahead of the group. On top of that I was reeling in rider after rider, feeling like Lance Armstrong racing up the Hautacam! Lol! Changing back to the road back (much quicker than the first change) as soon as I reached the tarmac I had moved up about 40 places. So, all in all, well worth the bike change when hitting the dirt. Ride on!
Use the A key hack next time to stop quicker, and you’ll grab even more places!
Cheers for that Eric 👍🏼
I had planned to swap, but since I was in a nice group when we got to the jungle decided to stay put. Didn’t see any MTB go past us, so I think it was right for me.
I had the same dilemma – to swap, or not…I opted to stick on the roadie as had been caught by a group just before the jungle began. They didn’t stop to swap, so neither did I! Worked out okay as the group speeds were similar to what I’ve achieved on the MTB solo…
Incidentally – no big loop Strava section for me on this event, despite gaining the route badge 🙁
Yeah, we’re trying to create a Strava segment from the pens, but Strava isn’t letting us. Gotta love Strava…
I made a similar mistake on Stage 3 last night (8pm UK time).
Was in a group of about 8 in about 40th place, hit the dirt and immediately swapped to MTB. I should have waited, the group on the downhill were travelling at a great pace and it took me two-thirds of the lap to catch them. Sweaty fingers on laptop touchpad lost a few seconds and yes the bridges didn’t help either, but I was at least “30 seconds” behind mostly due to the slowing and getting back up to speed.
I really gained ground as the dirt went upwards though and flew past the group at the end of the jungle lap, even overtook a few stragglers such was the pace differential uphill, finding myself in 32nd place. Stopped on the tarmac and switched back to my climbing bike setup and was still a good 10 seconds ahead of the group. Admittedly, I was holding a bit more power (over 4.0w/kg) on the uphill half but I was probably working harder on the downhill than the group and I wasn’t catching them.
I powered away solo up the hill and actually got about 10-20 seconds further ahead, but they slowly started to catch me on the downhill so I decided to let the same (now larger) group catch me before the 1% uphill zig-zags. This worked well and I powered back into the group as they caught me and we carried on until the final sprint, finishing about 34th. I’d started late so this is a good result.
I think the optimum tactic (if in a decent group) is to wait until you’ve completed the downhill drafting on dirt and bridges and change to the MTB as soon as you are on the uphill dirt, the gap will be smaller due to the slower group speed so you’ll quickly catch and pass them on the climb.
Also, I love how your avatar moves into an aero position on the MTB at the same speeds as on the road bikes. I wonder, does the position change actually give less air resistance, could be worth testing at 30km/h!
The more aero position doesn’t actually change anything–it’s just a visual.
Yeah, I’m liking the “wait until the uphill” strategy, at least for double draft events. I think I’ll try that next.
On my TdZ Stage 3 ride I did the swap as well. I think I gained over 25 positions by the time the Jungle Circuit was done. And I still had time to swap back to my roadie and stay ahead of the pack I left in the dust.
Did Big Loop this morning. Took a gamble with the Canyon Grail from the start. Managed to maintain pos 9-11 in a trio up the climb, down the other side and over to the jungle. Put down a bit more pressure on the Jungle decent and lost one from the trio. However for the whole decent I couldn’t shake the Tron from my wheel but I did notice some gain on next pos ahead. It was the Jungle climb that held the biggest gain. Immediately I dropped my wheel sucker and started gaining on those ahead. I bridged up to 4th and claimed back around 2 mins in the process. All this gain was happening whilst they were putting out 5w/k and me around 4.5w/k – awesome! As the gravel turned to tarmac I made a decision to switch to the Tron in my garage. Once the switch was done, pos 5 rolled past and we were able to ride together to the finish. The riders who I entered the jungle with finished around 1:30-2:00 behind. Well worth the bike hopping.
I would be hesitant to try this using my AppleTV 4k remote. Seriously, there might be a benefit in “practicing” bike swaps.
Hi Eric,
I think the mistake was that you’ve changed bikes when you hit the dirt. You should change right after the windmill,when the road gets flat from 2% to 1%,right before the descent into the Jungle. That way you gain crapload of speed (still behind the group you’ve traveled with before),AND you’d hit the dirt with that speed,while the roadies slowing down on the entrance to the Jungle. That would reduced your disadvantage greatly! 😉
Don’t you have to come to a complete stop to change bikes? That feels like a huge loss in momentum that would be extremely hard to compensate for, twice.
I swapped as well during stage 3 yesterday, however swap was very messy and in the end I lost one place due to this; went from 8 -> 9 and was only able to catch up couple km’s before finish-line (didn’t bother to sprint).
As we were a bit spread out when entering the jungle (10s behind group of 2, 10 sec in front of another solo rider. Bigger group ~1min back) I noticed that I was not really making up any time on the small groups further on the road (dirt) despite similar Wkg (appr. 4-4.5) except for the climbing portion.
All in, I don’t think it was worth it … although the end-result would still be the same
I changed to the MTB approx placed 530ish – fell to 570 but finished at 510 when I swapped back. Definitely works for me
I didn’t try it but in the TDZ group ride someone who was with the chase group did. Our group was in 17th-28 when we hit the jungle lap.
A rider switch to the MTB, but that was a huge disadvantage for him-here’s why:
I knew he was going to switch back at the end of the jungle lap. Therefore he would need to have a big gap in order to make up for the switch coming out. So the other riders and I just rode his wheel and kept up with the accelerations. Plain and simple. That rider never made it back after switching back.
It puts a target on your back.
After reading this post (thank you!) I swapped at the start of the Jungle climb after the wood bridges as I was in a small group on the descent. If I was solo on the way down I would have switched then. I went from 91 to 81 on the climb and came out at 86 after the swap back to the road bike. Doesn’t sound like much in terms of places but I had made it into the group ahead and it helped save my legs for the remainder of the ride. I was using a PC nearby so my swaps were pretty fast (~5 secs)
I did the swap but waited for the first small incline to swap so I stopped faster. I was with a small group that gained 10 seconds on me. I had that 10 seconds back in 1-2 mins. I ended up dropping 60 places from 340/700 to 280/700. So I was a little further back in the pack. Would stand to reason that the further back in the pack (the slower everyone is) the bigger of an advantage the switch is. Regardless of the actual time benefit, I went from riding with a group passing a few folks here and there to flying by people, it was glorious!
I did the same on Wednesday and made up significantly more places than I lost due to the time stopped swapping (even fiddling with the ATV remote). Well worth it, and that with only the Zwift bog standard MTB.
During the long TdZ stage 3 (1/23), I did the swap as soon as we hit the jungle dirt. For me, it worked great as I picked up about 25 places, which was about the number of places I lost on the KOM. I didn’t bridge to any big groups though, the biggest was probably 4 riders. For this stage there were about 270 or so riders and I ended up finishing 90th. Had I not swapped, I’d have lost at least 10 or 20 more places judging from the names on the final leader board. I’ve been practicing the swap and have it down to under 15 seconds. Slowing down on the descent entering the jungle is the longest part of it. Going back to the road bike, you’re on a climb, so that slow down and swap out is quicker.
Hi Eric, if bike swapping is good enough for Chris Froome and your good self I thought I’d give it a whirl. Given, I was having another one of my ‘solo Group Rides’, I didn’t have to worry about losing a group’s draft benefits….Although I took a while to swap bikes (just to the standard Zwift MTB) I did gain a few places and it seemed to help me recover from a dreadful epic KOM that I had. I changed on the way down into Jungle (near the red and white barriers on this route) and then changed back to the road bike at the top of of the last rough tarmac climb out. It definitely worked for me and although I know it’s a ‘virtual’ game it felt more comfortable / ‘right’ riding a MTB across that type of terrain. One question though do you see / hear much from other Zwifter wanting actual group rides (rather than races in all but name) for these events? I know that there are such groups on Zwift and have enjoyed riding with them but it might be something for Tour De Zwift to consider next year e.g. have group leaders, possibly even use of the fence etc?
I swapped after top Epic Kom to gravel bike used downhill and gravel to make up time and positions. I improved about 60 + positions with swap.
I swapped into The Canyon Grail Gravel bike during this ride. Would it have been better to go with an MTB? What is faster over the Jungle route? The Gravel or MTB? Do gravel bikes get the draft?
Never mind I just saw the comment below.
Rode the Bambino Fondo today. Took the advice to swap the MTB at the bottom of the climb out of the waterfalls. Passed everyone not on a MTB on the way to the tarmac on the way back out! I use iOS so I don’t have a brake hack, but it didn’t take long to swap twice. Definitely worth the time to switch; not a race but I definitely gained time. Thanks for the insights—
The section titled “Roving gangs of hairy legged mtbers” is the best title for anything I’ve read in a long time! Thanks for all of your work Eric!!!
You laugh, but it could happen! 🙂