All About Zwift’s New Factory Tour Challenge

March 4, 2025

LAST UPDATED March 22, 2025

My friends, the day has finally arrived.

After years of Zwifters asking for a fourth in-game challenge, with Zwift Insider posting articles and the community offering heaps of challenge suggestions and even creating amazing concept art… it has arrived. Hurray!

Here’s a quick walkthrough:

Getting Started

You must be at level 40+ in order to take on the Factory Tour Challenge. Level 40+ riders probably already know how to sign up for Challenges but here’s a quick refresher anyway…

There are three ways to get signed up for the Factory Tour Challenge. The game actually prompted me to do it when I started my Zwift activity – that’s the first screen. It also showed up on my Challenges carousel on the homescreen (second screen). Lastly, you can always access the list of Challenges in the main menu, at the top-right:

What’s a “Power Unit”?

While the other three challenges (Climb Mt. Everest, Ride California, and Tour Italy) are based on accumulated distance or elevation, the Factory Tour Challenge is power-based. (The concept is that you’re powering a RoboPacer factory as you pedal your bike, so the animation for the challenge moves through the factory as you progress.)

Cyclists move through this challenge based strictly on the power you’re putting into the pedals, and progress is tracked using a metric Zwift calls “Power Units”.

One power unit is one watt-hour per kilogram, or Wh/kg. If you hold 1 w/kg (say, you’re an 80kg rider holding 80 watts) for an hour, that’s 1 Wh/kg, or 1 power unit. If you average 2 w/kg across your Zwift rides, each hour of riding will earn you 2 power units.

Finishing the Challenge

The Factory Tour Challenge is a 2-part challenge, like Climb Mt. Everest. The first part requires 250 power units to complete and awards you with Lightning Socks:

Once you finish the first part of the challenge, your progress will revert to 29% and you’ll automatically begin the second part which requires a whopping 600 additional power units to complete, unlocking the Aero Lightning Socks, which will replace your boring ol’ Lightning Socks.

How long will it take to complete the entire challenge? For riders, the math is fairly easy. Take your average w/kg multiplied by your hours of Zwifting per week. That’s how many power units you’ll be earning each week.

Examples:

1 w/kg for 5 hours each week earns 5 power units each week, requiring 170 weeks to complete the challenge
2 w/kg for 6 hours each week earns 12 power units each week, requiring 71 weeks to complete the challenge
3 w/kg for 7 hours each week earns 21 power units each week, requiring 40 weeks to complete the challenge

As you can see, this is no short-term challenge. And I think that’s a good thing.

About the Socks

The new Lightning and Aero Lightning socks work sort of like Fire Socks in that they unlock cool animations above certain effort levels:

Power < FTP * 1.5: No Effect
Power >= FTP * 1.5: Sparks and Tire Halo (both Lightning & Aero Lightning Socks)
Power >= FTP * 2.1: +Tire Sizzle Flash (both Lightning & Aero Lightning Socks)
Power >= FTP * 2.7: +Full Aero Lightning Effects (Aero Lightning Socks Only)
Power >= FTP * 3.2: +Lightning feet (Aero Lightning Socks Only)

In addition to the visuals, the Aero Lightning Socks are particularly special because they are the first piece of performance apparel in Zwift. When you wear the socks, you receive a slight CdA reduction, making you faster in game. (Just how much faster is unclear, but I’ll definitely test the socks once I’ve got ’em.)

A Few Gotchas

There are three limits built into the Factory Tour Challenge, presumably to discourage cheating:

You can earn up to 4 Power Units per hour. (This limit resets at the top of the hour, so in theory you could ride at 4 W/kg for one hour, then sprint at 10 W/kg for 24 minutes and earn a total of 8 power units in 84 minutes. Good luck!)
You can earn a total of 15 Power Units per activity. If you save your ride/run and start a new activity, this counter is reset.
If you get the Cone of Shame (read more about it here) your progress will not count towards the challenge.

Also, a note for Zwift runners: this challenge doesn’t apply to you. While in my tests the game was awarding Power Units while running, those Power Units weren’t actually saved to my account. Reaching out to Zwift, they confirmed that this challenge does not apply to running.