Boost Mode Race Testing (and feedback) May 6th-8th

Good fun, liked the extra gamification and there was always something to think about. Agree with the various comments about buttons, was definitely a bit of a challenge trying to figure out what to press when pushing for the climb or the Sprint. Not sure about the charge and boost split in two (had the balanced one). I think that is added complexity which could come later but a simple 1 charge / 1 boost would be better I think… Especially combined with the difficulty in finding the button was mainly frustrating as I generally would have liked to have the second half of the boost but couldn’t get to the button easily while sprinting! And winning the sprint at the end made my day :wink:

Personally I also was wondering wether my power number with the charge or release was my effective power or calculated.
I also thought the bar on the left was increasing or decreasing, but that bar didn’t move anything :rofl:

Keyboard shortcuts is a must.

First bug found from the 8am test. I’ll be making some config changes to the 5pm test today (and the Weds-Thurs) tests to address the bug. :slight_smile:

I also noticed (could be non related to the test race) that my pictures of the race where uploaded to the activity after the race.

Wes, My son was going to be riding on Zwift at the race time so I entered him in this event on my avatar and watched from the sidelines.
Whilst I tend to prefer a less gamefied method of indoor riding I was keen to see how this would look.
Aaron chose the 50W boost and got settled into the event. Once into the lap he was soon charging then boosting regularly and was loving it. He soon learned to charge when in draft if possible and boost up the cobbled climb or to grab a passing wheel.
Our keyboard and mouse are in easy reach so the controls were simple enough but can see keyboard options being handy for others.
Overall I think this is a fantastic addition to Zwift events and my son thought it was brilliant. It won’t be for everyone but others will

My feedback on my quick experience with boost. I did the lunchtime (NZT) race today and managed a few laps before Zwift crashed. I don’t think this is necessarily a Boost add on issue but more of a Crit City issue and i’ve had this problem before when I use my discrete graphics card…i forgot to switch to the integrated graphics this time…

Anyway…I chose the 500w boost to see what the difference would be like.

I expected a larger difference both in the charging and the actual boost. -150 watts seemed to have very little effect and charged pretty quick and the 500w boost was a bit hit and miss. Maybe I wrongly imagined a “nitro” boost need for speed effect but I thoughtabout 700w for 5 seconds (75kg) would net me a larger speed increase.

Either way I boosted and charged a good number of times in my short time and i don’t think i would pick the 500w boost again but i need some more experience with it. Maybe it might be used for bridging to a group and obviously for a sprint… but I was in a group of 3 so i was playing around with boosting off the front and dropping off the back and boosting back.

One thing I found myself wanting to see was an effective watts. my watts & Wkg + / - the charge / boost.

I’ve watched Nathan Guerra’s stream with the kids, couldn’t join :frowning: (I had to take over the kids, so I’ve decided it’s good fun to watch Nathan’s suffering together :wink: )

The boos mode looks like a ton of fun, and brings on an extra layer for strategy. My mind started racing immediately about 3R Figure 8 races where I usually get dropped on the climbs (89kg here)

My two cents:

  • shortkeys on keyboard would be nice
  • double tap to discharge at once or charge at once (probably already present?)
  • let me see who uses what kind of boost! colorize the arrows when they are using it or something
  • display overall boosted wattage on the results screen. Like if I’ve used the 200w boost 5 times, than either display 5x200 boost or 1000W boost or something. that would give the others an idea how many “extra watts” went into that position. It’s rather an informative element on a personal level (I like data) than an objectively useful one
  • fine tune the charge/boost ratio (as I’ve read in Eric’s article on ZwiftInsider they are already doing it)
  • allow racers to enter into races with boost WITHOUT choosing a boost and taking a weight penalty. I believe that for some team it"d be again another level of layer of strategy , for example if 5 of us join to a boost race without boost and penalty, and it has a longer than 90 seconds climb, we can work out a strategy to try to tear up the blob, escape at the front or something. Some more fun :slight_smile:


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Can we get the Back to the Future style fire trails from 2019 April Fools’ Day to show up when someone uses boost? That would be ace. :rofl:



I was saying some weeks ago that they could be used when someone’s sprinting at 2* FTP or more, but this would also be great.

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Used the + 50 watt setting, got dropped from the A group trying to sort out the terrible Apple TV remote, as usual! But got the hang of it after the first lap.
Kind of weird deploying a Power-up and boost simultaneously, but worked without a hitch.
As with the steering control, a lot for this old guy to think about while hanging on by my teeth!

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People say, “don’t knock it until you’ve tried it”, so I signed up for one of the test races so I could give Boost Mode a try.

I did not care for this feature at all.

Philosophically, I don’t like it because I want virtual racing to be as close to real racing as technology and safety allow (there’s no need to emulate crashes or road rage, but otherwise just plug me into the Matrix). After all, I’m the kind of person that doesn’t like using Power Ups because it feels like cheating.

From an implementation point-of-view, I got so fed up with the need to constantly press buttons, that I just gave up and rode around casually until the race was over.

I don’t intend on doing any more races in which this feature is used. Since my opinion appears to be in the minority, I guess that means no more Zwift races for me.

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Boost Mode is just one type of racing. More “traditional” Zwift racing is not going away simply because of new modes we are working on.

I appreciate you taking the time to try it out and give feedback. We know that everything we do isn’t for every type of Zwifter and that’s OK. :ride_on:


Also anyone who streamed their boost mode events, feel free to post the VoD links here, the research folks would love to see them.


Hi Some feedback after test 1a and 1b

It was fun to do and everything works well for me. I had not any problem with the button sizes.
It’s a complete different way of racing. If you are in a big group it was raining attacks. So it was harder than a normal race for me. So i’m sure a lot zwifters gonna love this but personally i prefer the most natural realistic way of indoor racing/riding for me . But anyway it’s great to have this events in the app so you can also offer the sportive gamers with tactics a funny race to do.
Cheers @Wes here is my stream

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From my race today

I’m thinking about whether it’s possible to add keyboard key to boost up and a key to use boost. it is not meant to cycle and use the mouse at the same time


These are my racing videos on 1a and 1b.
+1 for keyboard shortcuts because using mouse all the time is too cumbersome.
I have noticed that the medium boost took 9.5 seconds to charge with 100W, while give me 8.5 seconds of 200W so it should be a bug, but you might have fixed it already.
It was pretty easy to predict when the boost was used, and when they charge. On the Volcano circuit, no one used boost on the final Z-ramp, all of us saved boost on final sprint.
I and James were able to make a move using efficient boost & aero boost at the same time. James won while my energy didn’t last 90 seconds. That made a great assist that gave me all-out.
This was fun!
It was pretty easy to guess who using which boost. In the 1a Crit City, most racers are on medium.
On 1b Volcano, most are on efficient boost.
The weights of boosters are somewhat counter-intuitive, because efficient boost gives 90s-50W makes 4500 joules, balanced boost 17s-200W = 3400 joules, power burst 5s-500W = 2500 joules. That with most capacity is the lightest, is it intended?
And I felt the charge/boost cycle efficiency is unrealistically high. I mean, the “charge tax” is too small. For example, efficient boost gives me 22.5 seconds of boost while it takes 25 seconds to charge. It makes 90% efficiency. No current regenerative braking system achieve this efficiency. Yea, it is a sci-fi game, but I also felt it’s too easy to use boost and there’s almost no penalty to charge, while the pack is relaxed. For gamer’s point of view, it should be more “tactical”, so I want more penalty on using it so that requires more tactical foresight to use. I suppose 60% to 70% efficiency is good in both realistic and gaming point of view. Meaning 22.5 seconds of boost requires 30 to 40 seconds of charge.

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I just tested 2b ride in D category using the +/- 50 watts.

  1. I think there should be the “Equip” button on each choice displayed always. It was not clear that one had to hover to get the “Equp” button to appear.

  2. In D ride with +/- 50 for me nothing worked powerwise. No effort to charge. No power boost.


I rode on the flat pedaling at a mere 50 watts continuously. I then pressed the battery button and it charged up the segments quite rapidly with NO added effort required on my part. I just kept pedaling along at 50 watts as the segment(s) charged up.

I then kept pedaling at 50 watts and used green power boosts. I went no faster. My power and w/kg reading remained the same.

I also tested coasting down hills at zero watts pedal effort and using a green boost, and I went no fast and my power remained zero watts (coasting downhill).


I then quit and tried to rejoin to test if it might be my setup, the 50 watt setting, the D ride setting… but there was no “late join” option so I only go the one shot to test. Could we have late join enabled on these rides so we can test each of the various options available in the one ride? Thanks.


Relating to others’ comments for whom it worked about it being a bit too easy to charge for the reward, perhaps the battery should decay with time so you must keep it topped off or it will just passively discharge over time. So, you would have to either “trickle charge it” to keep it topped off and ready to use, or you would have to use it soon after charging or see it erode.

It would reduce the problem of cruising in the bunch and filling up a big boost and then having it 100% charged until you needed it. If you cruised in the bunch to charge, you would have to either keep a small penalty to trickle charge it, or you would have to move up and do your breakaway right away.

Just a thought.

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Feedback from Event 1a and 2b.

First part = loved it! In 1a due to human error and not having a gears (forget to re-install di2) I skipped a lap and spent the ride mucking around with the boost and how it worked. In this event I used the economy approach.

No bugs or feedback from this ride - I was having problems with companion app but pretty sure that was on my end vs anything to do with beta.

Ride 2b - “Raced” this one a bit more - used balanced and this changed the whole way the race worked especially chasing and working together in what turned out to be a reverse paceline where we boosted to get to move from back to front and then recharged as we dropped backed. Really liked how it changed this dynamic.

No bugs etc form my experience but found (as have previously) if sweating activating boost/charge is tough on the companion app. Nearly need a race screen that has Power Up, Boost, Recharge as the only buttons (Still the sweat might make it tough) / In the end I reverted to the apple tv remote which worked ok (if I could yell at SIRI life would be awesome :smile:)

My setup was for 1a = AppleTV with Iphone XR as companion app / 2b AppleTV via Elgato HD60S for streaming with Iphone XR as companion app. Everything on wired fibre connections (except phone)

Youtube of 2b @ with the reverse pace line in practie at 26:25 onwards. Just went through this video and I recharged 22 times / first 18 minutes 10x then next 10min 10x once we started to get a group dynamic.

Final Notes: This made racing feel incredibly more immersive vs a fitness test as you had to pay attention and think about actions other than a powerup. In fact I found combining a powerup and boosting to be a good approach. Main additions would be easy to use via headup or companion app.

Really enjoyed the boost race, all seemed to work as expected. I would like the buttons bigger on the companion app. I run Zwift on tv and use the companion app for to controls. If they were big like the power ups it would be good. The initial selection screen for boost on tv was being weird too. When I clicked menu button to select next, it brought up the keyboard??

The whole boost tactics was good and I was so desperate to charge that I chose a bad moment and dropped myself from the small group I was in. I know it was only a test but would prefer it if the Cats went off separately.