Cheapest Zwift Setup – From Bikeless to Riding under $200

November 06, 2021

Finished product

Zwift is a virtual world that you explore by biking or running in real life.

People usually Zwift by attaching a trainer to the rear wheel of a bike they already own. “Cheapest Zwift setup” articles list the lowest-cost equipment you need besides a bike.

I’m new to cycling and have a small apartment. If you’re also intrigued but hesitant to commit money and space: here’s how you can hack together a setup less than $200. It won’t win races… but helps you try out the world of Wattopia!

Parts List

Required:

Optional:

The Bike

I started with Amazon’s most popular “foldable exercise bike”: the $150 Exerpeutic Magnetic Upright. There’s now also several others (ex. 1, 2, 3) with similar internals for slightly less.

Pros: it’s affordable and takes the same floor space as a trash can when folded. I’ve used it for a year without issue.

Cons: It’s closer to a recumbent bike than a real bike. The max resistance is only moderate. Your posture/form will be inauthentic to real cycling.

Data Needed

Zwift’s gameplay centers around a measurement of our power output (wattage). You connect a bike to Zwift either through:

  • Power Sensor

    • Reports wattage from a trainer or pedals with special sensors
    • Not ideal: lowest price is 2x the folding bike
  • Speed Sensor

Wahoo Speed Sensor

We can hack the $40 Wahoo Speed Sensor to connect our folding bike to Zwift.

Since we don’t have a “back wheel”, this approach has two downsides:

  1. The setup acts as a “single gear bike” at all resistance settings.

    • Typical bikes use gears. As speed or elevation changes, you shift up/down to go as fast as efficiently possible.
    • Changing resistance difficulty doesn’t affect in-game speed. It only makes pedaling a certain speed easier or harder.
  2. The setup reports unrealistically low speeds to Zwift.

    • The sensor’s placement calculates correct speeds with a 4.32 meter wheel circumference.
    • This is larger than any bike wheel in existence – and not available as an option in Zwift.
    • Your virtual effort will be much lower than your actual effort (ex. ~20-40 watt, ~5-15 mph average).
    • Players in-game will often pass you and steep hills can be frustratingly slow.

Step 1: Dismantle Sensor

First, take the plastic body off the bike using a Phillips-head screwdriver. Inside, there are a series of belts and wheels that spin as you pedal.

Tight fit

There’s little room between each part. The Wahoo sensor is too big to fit out-of-the-box, but is remarkably thin without the plastic casing:

Sensor without plastic body

Carefully remove the battery and the circuit board from the plastic. Then, secure the battery to the sensor with electrical tape. Finally, cover the remaining exposed portions with electrical tape.

You can use the blinking blue LED and the Wahoo Fitness App to ensure the battery is securely connected.

It took me a few tries to tape the sensor so that the battery had a stable connection and it all fit properly in the wheel. Expect to experiment.

Step 2: Install Sensor

Once you’ve wrapped the sensor, it should snuggly fit inside one of the holes in wheel closest to the right pedal. Holes vary in size so try until you have a good fit.

Friction is sufficent to hold it in place – even during intense pedaling:

Sensor Placement

Step 3: Configure Sensor

In the Wahoo Fitness App, configure the sensor with a Custom Size tire of ~4.32 meters. This tire size results in data reported that lines up with the Exerpeutic’s stock speed sensor. This is just to verify the setup works – this setting doesn’t affect Zwift.

Configuring the Wahoo Speed Sensor with App

Optional: Wahoo Cadence Sensor

The Wahoo Speed sensor is different than the Wahoo Cadence sensor. It attaches near your pedals and reports revolutions per minute.

I wouldn’t recommend this for Zwift. Zwift accepts cadence data but only uses it for your in-game pedaling animation. It doesn’t (to my knowledge) affect in-game controls.

This sensor is more useful with spin workouts (ex. Peloton) which focus on cadence rather than output.

Enter Zwift

In your Zwift app, pair the Wahoo Speed Sensor. Configure it with a Tire Size of 700x32c and select “Not Listed” when selecting a trainer.

Zwift configuration for Wahoo Speed Sensor

If you have a heart rate or cadence sensor, optionally pair them too. Next: Let’s Go!

In-game screenshot while Zwifting

I’ve had fun with this – although my inaccurate speeds mean I’m not very fast 😝 I’ll consider a real bike at a thousand miles.


Dalton Flanagan is a software engineer & creator based in NYC.

© 2021 Dalton Flanagan