Believe it or not, you can do indoor cycling on a budget. Spending an enormous number of $$$ on a direct drive smart trainer is unnecessary – although it helps.
You can still do Zwift on a budget classic trainer. But you will still need something to connect the app with your bike.
That’s why we are looking at the best cadence and speed sensors for indoor cycling.
Pick one of these and you will have something that connects to your indoor cycling app. It will also work out on the road if that is your thing.
Two things to know.
First, we have tested these sensors out on a cycling app. Second, this site makes a bit of income if you click on a link and buy (at no cost to you) and it helps pay to keep this going.
No time to read the whole thing? Then our choice is the Wahoo Blue SC Speed and Cadence Sensor.
- How they were rated
- General information
- Wahoo Blue SC Speed and Cadence Sensor
- Magene Outdoor-Indoor Speed & Cadence Sensor
- Garmin Speed Sensor 2 and Cadence Sensor 2 Bundle
- Polar Speed and Cadence Sensor Bluetooth Smart Set
- Xoss Bike Cadence Sensor & Speed Sensor Speedometer
- What you need to know about buying a speed and cadence sensor for indoor cycling
- Standard turbo trainer with speed/cadence sensor
- Connecting Your Speed (and Cadence) Sensors to Zwift
- ANT+ Or Bluetooth (BLE)
- ANT+ – what is it?
- Bluetooth 4 – what is it?
- Types of Sensor
- Design of the Cadence Sensor
- How it works – Cadence Sensor:
- Summary
How they were rated
Speed and cadence sensors can supply a cycling app with the basic information it needs to move your bike along. If you are riding on Rouvy via a dumb trainer, you will need to change the resistance via your gears.
In fact, you can get away with just using a speed sensor, but cadence makes it a little more reliable.
With this is mind, the focus has been on battery life, using speed and cadence how the sensor fits the bike, how many devices can it link to, whether it had ANT+ and Bluetooth, and how easily it connects to a cycling application.
General information
Something else you will need for Zwift is an ANT+ dongle. Although these sensors make use of Bluetooth, you will also need an ANT+ dongle if you are using a laptop.
Here’s a list of the Best ANT+ Dongles for Indoor Cycling.
Using this sort of setup will get you moving on Zwift or Trainerroad. But you cannot race or benefit from ERG.
By the same token, it will provide a good basis for testing Zwift out and doing some hard training
| Image | Product | Features | Price |
|---|---|---|---|
 | Wahoo Blue Speed and Cadence Sensor
| 9.1 | Check Price |
 | POLAR Speed and Cadence Sensor
| 8.8 | Check Price |
 | Garmin Speed Sensor 2 and Cadence Sensor 2 Bundle, Bike Sensors to Monitor Speed and Pedaling Cadence
| 8.5 | Check Price |
 | Magene Outdoor Speed/Cadence Sensor for Cycling, Wireless Bluetooth/Ant+ Bike Computer RPM Sensor, Compatible with Wahoo Fitness, Strava
| 8 | Check Price |
 | XOSS X1 Bike Cadence and Speed Sensor
| 8 | Check Price |
Wahoo Blue SC Speed and Cadence Sensor
The Wahoo Blue SC Speed and Cadence Sensor is a single unit that combines both speed and cadence monitoring into one device. This means there’s no need to attach two separate sensors to your bike.
It is also magnet less. So there’s no need to add magnets to your spokes or cranks. One less thing to get wrong.
The sensor uses Bluetooth 4.0 for greater compatibility with your favorite products from Garmin, Bryton and other bike computers. It also supports ANT+.
It works well with Zwift or any other cycling app.
The sensor fits on the chainstay to the pedal and wheel pass. The unit is bulky, especially if the crank arms are thin. Also, the accuracy isn’t always as dependable as the other choices here.
We made it the number one choice. Why? You can beat having everything on one device, plus the connectivity was faultless.
- All in one component
- Links well with Zwift and other apps
- No magnets so it is easy to install
- Can be a bit fiddly to get capture both speed and cadence
Magene Outdoor-Indoor Speed & Cadence Sensor
The Magene Speed and Cadence Sensor is a great option for cyclists who want to track their speed and cadence without spending a lot of money. This affordable duo comes with ANT+ and Bluetooth 4 for compatibility with Garmin, Wahoo and other bike computers.
Be aware, this review is for two. You will need both if you are looking for speed and cadence.
This combination speed and cadence sensor also supports Bluetooth and ANT+ connectivity. ANT+ is a common wireless technology used in many biking-related devices, including bike computers, cadence and speed sensors, and even bike trainers.
It also works fine with many indoor cycling apps, including Zwift.
Just using one? Switching between speed and cadence monitoring is as simple as reinstalling the battery. Each coin battery lasts about 400 hours, which is about standard.
- Easy to install. Connects easily to other products via BT.
- Nicely packaged.
- Comes with attachment bands.
- Cheap as it’s non-brand.
- Problems connecting with other apps, like Wahoo.
- The battery must be changed if you want to switch modes.
Garmin Speed Sensor 2 and Cadence Sensor 2 Bundle
The Garmin Speed Sensor 2 and Cadence Sensor 2 Bundle is a great option for people who already own a Garmin device. The bundle includes two sensors. Both are ANT+ and BT compatible.
The sensors work with a variety of Garmin devices, including the Edge 1000, Edge 520 Plus, Edge 820, Edge Explore 820, Edge 1030, Forerunner 645 Music, Fenix 5 Plus, Forerunner 935 and many more.
The sensors are easy to install and use. They connect to your bike via a simple quarter-turn mount that uses a rubber O-ring to keep it in place. The sensor itself is small enough to fit on most crank arms without interfering with pedaling.
Users have reported issues in terms of connectivity with non-Garmin devices. However, nothing has come up at this end.
The speed sensor attaches to the hub of either wheel and self-calibrates with your Edge cycling computer or compatible Garmin device. The cadence sensor fastens to any sized crank arm.
The previous Garmin speed and cadence sensor only had ANT+ connectivity. ANT+ and Bluetooth Low Energy technology accurately transmit live speed, distance, and cadence data to compatible displays and apps.
- Links in with Garmin devices.
- Pretty simple to pick up via ANT+.
- Issues connecting with some non-Garmin products.
Polar Speed and Cadence Sensor Bluetooth Smart Set
The Polar Speed and Cadence Sensor is a two-piece set up with speed and cadence separate. The sensor is easy to install, but you’ll need to purchase an additional magnet for the cadence part of the sensor if your bike doesn’t have one already.
Here, the Polar speed sensor is supposed to fit on the fork. However, for our indoor cycling purposes, it will need to go on the rear chain stay.
While the cadence sensor goes on the opposite one.
The unit is ANT+ and Bluetooth compatible, so we can use it with most popular bike computers and apps.
In terms of apps, it works fine with Zwift. It also connected to iOS and Android devices, as well as Polar’s own apps (if you want to use them).
Unfortunately, the batteries aren’t replaceable, so you’ll need to buy a new sensor when they run out. The good news is, the long life means you won’t need to replace it for a good while. We’ve heard of these units still going strong 2 years after installation.
- Good connectivity
- Low energy use - long lasting battery
- Cannot replace battery
Xoss Bike Cadence Sensor & Speed Sensor Speedometer
The Xoss Bike Cadence Sensor & Speed Sensor is a good option for people who already own a Garmin device. The package comes with two sensors, one for cadence and the other for speed.
Both are ANT+ and Bluetooth compatible. There’s an LED indicator to show speed or cadence.
It works well with most apps like Zwift and Rouvy. And is good value for the money if you are not brand conscious.
On the downside, cadence is not the most accurate of those tested, and pairing can be difficult. Switching modes requires a battery change.
- There’s an LED indicator to show speed or cadence.
- Works well with most apps like Zwift and Rouvy.
- Good value.
- Cadence is slightly less accurate.
What you need to know about buying a speed and cadence sensor for indoor cycling
A cadence and speed sensor are necessary if you want to use a classic trainer with an indoor cycling app. Connectivity and ease of use are the first things to look at.
However, speed and cadence sensors can have other uses.
For example, it’s worthwhile monitoring your cadence when cycling outside. A high cadence is generally better for endurance.
Connecting the sensors to a bike computer for an indoor session can be done – if you want to give Zwift a rest.
Standard turbo trainer with speed/cadence sensor
For riders who want to ride without having to buy a direct drive trainer, Zwift offers a variety of options including a standard turbo trainer, a Virtual Trainer pedal unit, a wireless heart rate monitor, and a pair of Speed Sensors.
Watts are calculated based on cadence and speed sensors. However, any change to resistance needs to come from the rider.
Connecting Your Speed (and Cadence) Sensors to Zwift
Some magnetic trainers have multiple resistance levels. Zwift will tell you which level to choose when you select it. You should always set your trainer on the same level while riding.
We are assuming you are going to spend the bulk of your time indoors, so connectivity is going to be key.
ANT+ Or Bluetooth (BLE)
ANT+ is designed for connecting multiple devices together simultaneously. Bluetooth allows connection to one device at a time. Want to connect your heart rate monitor and Zwift? You need to choose what one.
Both types of sensors are excellent for picking up and sending your data to Zwift. However, it appears the connection drops occasionally with ANT+. This might be because there are other devices connected at the same moment.
ANT+ – what is it?
ANT+ is a wireless protocol standard that enables a device to transmit data to other devices. Several industries have adopted ANT+ and it’s regarded the successor to Bluetooth.
In fitness, ANT+ enabled devices work on heart rate monitors, power meters, bike computers, and many other devices. Healthcare also uses ANT+ in devices like ECG monitors or blood pressure cuffs. In the automotive industry, ANT+ can be found in devices like airbags or navigation systems.
For cycling apps it is useful as it can handle several connections.
Bluetooth 4 – what is it?
Bluetooth 4 is also known as Bluetooth Smart or Bluetooth Low Energy or BLE. It is an upgrade to the original Bluetooth. The major innovation was the reduction in power usage. It’s been around for the last 12 years.
It is designed for low data-rate short range connections, optimized for very low power consumption, suitability for wireless earpieces and sensors in wearable devices.
It offers two major advantages over previous generations of Bluetooth:
1) Reduced power consumption – This feature will allow devices to stay connected without the need of having to be charged all the time, which makes it ideal for smart watches, fitness trackers and other devices that require long battery life.
2) Increased functionality – The low energy that this generation of Bluetooth consumes allows it to operate on a single coin cell battery that can last up to three years.
A new Bluetooth is coming dubbed (unsurprisingly) Bluetooth 5. It offers a lot of improvements over the current version of the technology, but is it worth upgrading?
Probably not.
The Bluetooth 5 update aims to make wireless connections more reliable and faster for both hardware manufacturers and consumers. It also introduces new features that will be useful in smart homes and even with medical devices.
Types of Sensor
There are two different cycling sensors. Cadence sensors measure how fast you pedal. Speed sensors measure your overall speed.
There are many types of sensors used in cycling. Some are speed-only, some are cadence only, some are speed and cadence combos, and others are speed or cadence or both.
Design of the Cadence Sensor
A cadence sensor records the number of revolutions made by the pedals per minute. Cadence is measured in rotations per minute.
RPMs are expressed numerically or using letters of the alphabet. For example, 60 rpm equals 1 revolution every second.
How it works – Cadence Sensor:
To switch over to the cadence sensing system, first you’ll need to use some rubber bands to secure the sensors onto your bicycle chain. You should place them on the inside of the chain because that provides better protection from the outside of the chain where your shoes might swipe by.
You should know cadence sensors require around 8mm of clearances above the chain ring. So, make sure that your cranks are properly adjusted or else you might run into problems.
In my experience, most folks will want to place the sensor about 4 inches below the BB or slightly higher depending upon how far away from the chain ring/sprocket combo you’re riding.
You’ll also see some folks use the sensor as close to the top tube as possible. That works too, but it may require a bit of change to get the sensor reading right. For me, the sensor needs to be in the middle of the frame, and ideally, right above the seat post.
Summary
There are a lot of reasons for ditching the smart turbo trainer and going for this sort of set up. Besides it being cheaper.
For starters. It is much more portable – a smart trainer can take up a huge amount of space. They are too heavy to carry around.
Classic trainers are also easier to maintain, thanks to their simple design. Moreover – sometimes – a fluid trainer can provide a much better ride feel.
On the downside, power readings from a cadence and speed sensor will never be reliable. But if you want to manage functional threshold power, then they should give you something to aim at.