Most Zwift races come down to a pack sprint, and many of those sprints are won by a half-second or less. Because of this, smart racers would be well-served to understand how powerups and equipment selection influence their sprint times.
We’ve recently run a bevy of tests to learn how variations in rider weight, height, power, powerups, and frame/wheel choice affect sprint times. We’ve summarized the findings of these results below, but if you’d like to dig into the raw timing data you can do so on this Google sheet, under the “Sprints (Richmond)” tab.
Methodology
We ran a series of test sprints on Richmond’s Monument Avenue forward sprint segment. We selected this sprint because the road is quite flat, straight, and the sprint lasts approximately 15 seconds, so our powerups can run for the length of the sprint.
Our tests were run in isolation (no drafting other riders) at various rider weights, heights, and steady-state wattages. We also tested various frames and wheelsets. Unless stated, test results shown below are from a 75kg, 183cm male rider holding 750 watts.
Our rider held the set wattage for at least a few kilometers leading into the sprint to ensure that acceleration from wattage changes did not affect sprint times. When powerups were being tested, we activated them at the sprint start line so they would run for the entire length of the sprint. (While this may not be what happens in a race situation, it was the most repeatable methodology for the purpose of these tests.)


Aero Powerup Advantage
The aero powerup improves sprint times significantly, which explains why it’s the most coveted powerup for a race finish!
The amount of time saved by the aero powerup decreases slightly as wattage (and therefore speed) increases:
- 900 watts (12 w/kg): 0.56 seconds faster
- 750 watts (10 w/kg): 0.60 seconds faster
- 600 watts (8 w/kg): 0.63 seconds faster
The time saved by using the aero powerup in a sprint is quite consistent across different combinations of frames and wheelsets, varying 0.02 seconds or less between different frames/wheelsets.
Once we computed the time advantage of the aero powerup, we could attempt the sprints without an aero powerup, increasing the power to match the time delivered by the aero powerup. This tells us how much additional power you would need to hold to compete with a rider using the aero powerup. Or to put it another way, it tells us what the “wattage bonus” of the aero powerup is.
- 900 watts (12 w/kg): 115 watts
- 750 watts (10 w/kg): 100 watts
- 600 watts (8 w/kg): 80 watts
So the faster you’re going, the more of a wattage “bonus” the aero powerup offers.

Feather Powerup Advantage
The feather powerup improves sprint times consistently, regardless of which frame or wheelset you use:
- Felt AR with Zipp 858/Super9 wheels at 750 watts (10 w/kg): 0.17 seconds faster
- Specialized Venge S-Works with Zipp 858 wheels at 750 watts (10 w/kg): 0.18 seconds faster
- Trek Madone with Zipp 858 wheels at 750 watts (10 w/kg): 0.16 seconds faster
- Tron bike at 750 watts (10 w/kg): 0.16 seconds faster
- Zwift Carbon with 32mm Carbon wheels at 750 watts (10 w/kg): 0.17 seconds faster
The amount of time saved by the feather powerup varies when wattage varies, but not in a consistent way we can explain. Here are the results of our tests (repeated to make sure they’re correct):
- 900 watts (12 w/kg): 0.16 seconds faster
- 750 watts (10 w/kg): 0.16 seconds faster
- 600 watts (8 w/kg): 0.10 seconds faster
Rider Height
We already know height significantly affects speed in Zwift, since it is used to compute your virtual CdA. Our tests showed that, all other things being equal, every 10cm of height added results in a sprint which is 0.16-0.21 seconds slower:
- 203cm at 750 watts (10 w/kg): 14.66 seconds
- 193cm at 750 watts (10 w/kg): 14.5 seconds (0.16 seconds faster)
- 183cm at 750 watts (10 w/kg): 14.32 seconds (0.18 seconds faster)
- 173cm at 750 watts (10 w/kg): 14.13 seconds (0.19 seconds faster)
- 163cm at 750 watts (10 w/kg): 13.97 seconds (0.16 seconds faster)
- 153cm at 750 watts (10 w/kg): 13.76 seconds (0.21 seconds faster)
Frame and Wheelset Choice
Your frame and wheel choice affect sprint times, in approximately the same ratio as they affect times at normal race speeds. Therefore, our lists of fastest frames and fastest wheels also holds true for sprinting.
Examples:
- Upgrading from the 32mm carbon wheels to super-fast disc wheels will reduce your time in an hourlong flat race by approximately 1.71%. That same wheel swap will reduce your sprint time by 1.89%.
- Upgrading from the Zwift Carbon to the fast Felt AR will reduce your time in an hourlong flat race by approximately 0.55%. That same frame swap will reduce your sprint time by 0.41%.
Note: without more timing accuracy in-game and on Strava, it is difficult to determine if the percentage variances above are due to in-game physics or rounding.
Presumably due to rounding (Zwift only tracks sprint times to two decimal places), all of the wheels on our short fastest wheels list turn in the same sprint times, except for the three disc wheelsets, which turn in times .05 seconds faster. Similarly, the first four frames in our fastest frames list turn in essentially the same sprint times.
Therefore, your fastest sprint setups on flat ground will be (from fastest to slowest):
- Any of the first four frames in our fastest frames list, coupled with one of the disc wheelsets
- Tron (Concept Z1) bike (0.01-0.03 seconds slower than #1)
- Any of the first four frames in our fastest frames list, coupled one of the wheelsets on our fastest wheels list (0.01-0.02 seconds slower than #2)
By comparison, the base Zwift Carbon frame with 32mm wheels which every Zwifter begins with turns in a sprint time 0.33 seconds slower than #1 above.
Questions or Comments?
Post below!
So Specialized S-Works Venge w/ Zipp 858/Super9 wheelset and Aero Power-up is the fastest “Road Bike” combination currently on Zwift — or insert the other fastest frames (Felt DA, S5, etc…) which are virtually the same cause Zwift isn’t going out 3 decimal points. I’d imagine if you’re in a race that allows TT bikes theres a hand-full of TT bikes that would be faster; albeit, without drafting ability in a race you’re not likely to be in the final sprint.
Is there any benefit to the draft boost power up when you are solo (i.e. not drafting)?
Nope!
Curious if you use the draft boost (the van/truck) and you are on the front of the group – still with the group though. Do you get a benefit being #1 rider in the group but not otf with this power up?
If you’re on the front that means you aren’t drafting, which means the draft boost doesn’t have any effect.
So, then would Tron be fastest if you incorporate weight of bike/wheels as well (assuming a non climbing race)? Again, assuming drafting race, not TT. Seems the Zipp disc’s will be heavier than a Tron…😳
What I’ve wondered about the sprint is what’s the effect of power ups and wheels on the acceleration part from say 400w to say 800w. Different test and not sure how you’d do it. I often use the 454s and believe in my head they’ll accelerate faster.
I’ve tried to test this, but just can’t get the precision required to have meaningful results. My guess is you won’t find much difference between any of the high-end wheelsets.
All the weight and height at uff like this is disheartening for a 190cm 91kg guy like myself.
But you wouldn’t be putting out the watts you do, if you weren’t tall and heavy…..
Well the good news for you is that lighter riders have to output a higher w/kg to go at the same speed as you.
Be more interesting to see if there are differences in acceleration…
Or deceleration i.e if were to use a powerup leading into the sprint, hitting the start of the sprint at max speed and decelerating (albeit slight) when powerup finishes. Of course this is purely for a sprint time and not placing within a pack with draft dynamics
Yes. I think that’s interesting. I seem to get slightly faster sprint times when I hit the start of the sprint hard then lose power toward the end (but keep the speed) than I do if I build power slightly over the course of the sprint.
I’m only 47 kg & 152.4 cm. It’s frustrating to do a social ride that’s <2.5 w/kg. I have to work hard to keep up with the larger folks that put out more watts & speed than me doing same w/kg. I get my ride thrown out. Zwiftpower forced me to move up to category C & my average is 2.6 w/kg but at 47 kg I have to work to stay in the group. Zwiftpower ditched my social ride Monday for no HR monitor & there were others no HR monitor but still placed. They also separated the categories… Read more »
Yes, what we need to know is weight of the beacon. After a while you learn to factor it in when signing up, assuming the beacon is the default male (75kg), and pick lower rated events. Then every once in a while a woman is beacon and it’s all easier! Doing the same event can help as often the same person leads them. Ignore zwiftpower for group rides!? Why can’t zwift insider change their weight and power to reflect normal women in some of these tests. For example – especially for wheel sets – do those heavy disk wheels still… Read more »
I weigh 44kg and I’m 163cm tall, technically I’m in A for racing, but I still get dropped in B because I don’t weigh much. Group rides can be annoying as they say 2.5-2.8w/kg, when I’m pushing 4w/kg and barely hanging onto the bunch. Also effective w/kg isn’t taken into account on Zwift, as I can have the same bike as a 90kg rider, but the bike weighs more in proportion to me then it does for the 90kg rider. Zwift doesn’t really cater to light riders.
Great article! I also wonder when is the best time to activate the power up? During the acceleration , or when at full speed? And for winning the sprint jersey: I read somewhere you need to be at top speed when you pass the start of the sprint. So is it best to activate the power up before the start? Any advice there?
I pulled a back muscle once reaching for the laptop mid-sprint. Do it before you start.
Haha, that’s why I use the companion app. And have it right in front of me!
to do a good sprint, you gotta be able to sprint for minimum 400m/ 500m. the reason is, the faster you hit that 300m to go line, the better your sprint will be – even if dying in the last 100, if you can keep rolling the gear albeit 60rpm, your speed will not drop much if at all. its the speed over the 300meters – not the wpg that gets the good time; so activating it 5-7 seconds before the sprint line, and then maintaining is by far better than activating it at the 300 and have it end… Read more »
Thanks! Great tips. But always my fastest sprint times are when I have a leadout (and draft). Would be interesting to see what I can achieve with a TT bike though…
I think it’s best to activate the powerup a little early, and have a few seconds without a powerup at the end of the sprint… than to wait and activate it later.
And the number of people reducing their in game height has just increased exponentially……
Actually. I have recently had a medical issue and love weight and height doping. I can now stay with my friends and do a couple of group rides. Not possible with my IRL friends. I do not race and Zwift is 100% social ATM.
Might be my imagination but it feels like heavier faster disc wheels take longer to get moving in a sprint. Is there any tests for this, say the time it takes to go from 35kph to 50kph?
Nothing I can test precisely, no.
How come a 163cm rider gets the same time as a 193cm rider? It doesn’t follow the trend that the others do.
Where do you see that?
Eric,
Strange how a Zipp 808 (or for that matter the discs) are considered good for sprinting. Is there not a modeled effect given to being able to get the disc to spin up the speed it needs? Sprinting is all kinetic energy change, while TT is steady effort with few drastic kinetic energy changes. Where do you document your sprint tests?
The data is linked in the post. It’s the “Sprints (Richmond)” tab of these Google sheet: https://docs.google.com/spreadsheets/d/1_dvNbBEKAztJwjX-2CDdWmVSR4jP92o-eiNCB7hl5IY/edit#gid=495329711