There is no question that using a smart trainer with a built in power meter is the ultimate way to experience online, connected training and racing with Zwift. A smart trainer can change resistance on the fly, simulating headwinds or hills, creating a "close to real" experience. 

There is a downside, however - smart trainers are very expensive! Even the next-best option, a traditional "dumb" trainer combined with a power meter hub, crank, or pedals on your bike can still set you back $500 or more. 

There's a way to access Zwift without a power meter at all, however - a great option for riders for whom smart trainers and power meters remain out of reach. This approach uses an ANT+ / Bluetooth speed sensor that you add to your bike's wheel. Here's how you can set it up for less than $200.

What you need to use Zwift with a speed sensor

• The Zwift program (for Mac or PC) or app (on mobile devices)
• Your bike
• A "dumb" indoor trainer, like most rear wheel mag or fluid resistance trainers, or Feedback's Omnium trainer, from Zwift's list of compatible "Classic" models: https://www.zwift.com/hardware NOTE: Zwift tests the listed trainers in a lab so that your speed can be translated into an estimated power output based on the specific trainer you are using. If it's not on this list, it won't work.
• An add-on speed sensor that uses the ANT+ and Bluetooth protocols to communicate (they almost all handle both)
• If you plan to use a Mac/PC to run Zwift, you'll need an ANT+ USB stick, because ANT+ is not built into desktop or laptop computers. If you plan to use the mobile app, this part is not needed; Bluetooth is used instead. 

Which speed sensor to buy

There are about 20 different options on the market that all work the same way - a small plastic device about the size of a quarter that attach to your front or rear hub with a small rubber strap. Most run on CR2032 coin batteries and weigh next to nothing. 

Popular brands include Garmin, CatEye, Bontrager, etc. You can also find some "no-name" styles as well. Choose one that takes the common CR2032 batteries and supports both ANT+ and Bluetooth protocols for the widest compatibility. Models that also measure cadence are available if you like that option. 

In addition to indoor Zwifting, you can use the same speed sensor while riding outdoors too, in combination with GPS computers like Garmin or Wahoo. They can increase accuracy compared with GPS-only riding (for example, when you go through a tunnel and lose GPS signal.)

Instructions for using the speed sensor with Zwift

1. Put your bike on the indoor trainer
2. Install the new speed sensor on a wheel that will be turning when you pedal (either will work fine for rollers; use the rear wheel on trainers where the front wheel doesn't turn when riding indoors)
3. Spin the wheel with the speed sensor. On many brands, this takes them out of a battery-saving mode and gets them ready to connect. 
4. Start Zwift and follow the prompts to pair your devices, making sure to include the speed sensor. When prompted, select your specific model of indoor trainer. 
5. Start riding

I hope this information helps you access Zwift in a cost-controlled manner. Good luck!