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This article includes the best cycling radars you can buy to enhance your safety on the roads.
They become one of the most popular cycling accessories because they increase riders’ awareness by alerting them about moving objects through their bike computer.
I have extensive hands-on experience with all radars in this article and also with those that didn’t make it here. You will learn their pros and cons so you can make an educated decision.
The best radar overall is the Garmin Varia RTL515. Despite being among the first radars, it’s my benchmark radar. It’s the most reliable and accurate in (multi)car detection. It has decent battery life and excellent brightness. Its main downsides are the bad mount, often sliding on the seatpost, and MicroUSB charging.
Continue reading to learn how to choose a bicycle radar, how it works, and much more.
What Are the Best Cycling Radars?
The best cycling radars have to be reliable. This means they won’t give false negatives (won’t alert you about an incoming car).
They should have a taillight and battery life for about 4-6 hours long bike rides and be water and dust-proof.
Learn more about the bicycle radars features in this guide.
Garmin Varia RTL515 (Best Cycling Radar Overall)
Main Features
- False positives: Almost none
- Reliable and proven
- Excellent multi-object detection
- Good battery life
- Excellent light visibility
- Improves side visibility as well
- Smartphone compatibility
- Only MicroUSB charging port
- No light modes customizability
Technical Specs
- Claimed battery life
- 6 hours solid
- 8 hours peloton
- 6 hours night flash
- 16 hours day flash
- Real battery life: 9.5 hours in flash mode (2-year-old device)
- Taillight: Yes
- Camera: No
- Connectivity: ANT+, Bluetooth
- Charging port: MicroUSB
- IPX7
Garmin Varia RTL515 is the most popular bike radar on the market. The Varia family is the reason why cycling radars became so popular.
It’s the successor of the RTL510, which didn’t have Bluetooth and, therefore, smartphone compatibility.
RTL515 is reliable and has light with excellent visibility in daylight (Garmin claims up to 1 mile), so car drivers won’t overlook you.
Of course, it has multiple light modes, including the ‘peloton mode,’ which dims the light during a group ride.
It can detect multiple cars at once up to 140 meters away. Its multi-object detection is excellent. Based on my experience, having false positives (what’s this?) is rare.
Buying RTL515 was one of the best investments into my safety on a bike, right after a helmet.
Read my Garmin Varia RTL515 review for more in-depth info.
Also available at rei.com, performancebike.com, trekbikes.com, and wiggle.com
Magene L508 (Best Budget Cycling Radar)
Main Features
- False positives: Several per ride
- Affordable
- Sleek design
- Customizable light modes
- Smart brake sensing
- Poor multi-object detection
- Doesn’t improve side visibility
Technical Specs
- Claimed battery life:
- 4-11 h solid
- 10-16 h peloton
- 15-18 h quick flash
- 11-13 h pulse, flash
- 10-12 h rotation
- 19 h radar only
- Real battery life: 7.5 hours in flash mode
- Taillight: Yes
- Camera: No
- Connectivity: ANT+, Bluetooth
- Charging port: USB-C
- IPX7
Magene L508 is the first non-Garmin bicycle radar. It’s like Varia RTL515 but is more affordable and offers more features.
These features include the customizability of the light interval and brightness in the Magene app and smart brake sensing, which changes the light when you brake.
I used L508 for a few months, noticing that it gives me more false positives (what’s this?) than Varia. However, it never missed a car.
After the firmware update, it is also brighter, but in exchange for shorter battery life. It also struggles with multi-object detection.
So, if you want to save money, you can choose L508 instead of RTL515.
Read my Magene L508 review for more in-depth info.
Also available at aliexpress.com
Garmin Varia RCT715 (Best Cycling Radar with Camera)
Main Features
- False positives: Almost none
- The only radar with taillight and camera
- 1080p footage (but poor quality)
- Pricey
- Excellent multi-object detection
Technical Specs
- Claimed battery life (1080p recording on):
- 4 hours solid or night flash
- 5 hours peloton
- 6 hours day flash
- Real battery life: Almost 5 hours in flash mode and with recording on
- Taillight: Yes
- Camera: Yes
- Connectivity: ANT+, Bluetooth
- Charging port: USB-C
- IPX7
Varia RCT715 is the first (and still the only) device that combines radar, camera, and taillight functionality. That’s why it’s automatically the best cycling radar with the camera.
The idea behind it is excellent. But, unfortunately, the execution by Garmin is not the best. Let me explain why.
RCT715 can record 1080p footage so that you will have proof in case of an accident. However, the footage quality is bad in low-light conditions. So, you may struggle to read the license plates of cars.
Furthermore, its price is high, so it’s not as affordable as RTL515 or L508. Finally, the Varia App was slow and buggy when I tested it.
These issues make RCT715 suitable only for people who desperately want the 3-in-1 functionality.
Read my Garmin Varia RCT715 review for more in-depth info or this comparison of Varia RCT715 vs. RTL515.
Also available at rei.com and wiggle.com
| Cycling Radar | Battery Life | Taillight / Camera | Mount Stability | Multi-object Detection | Price Range | Buy |
|---|---|---|---|---|---|---|
| Garmin Varia RTL515 | 6 hours solid 8 hours peloton 6 hours night flash 16 hours day flash | Yes / No | Bad | Excellent | $$ | Check Price Check Price (rei.com) |
| Magene L508 | 4-11 hours solid 10-16 hours peloton 15-18 hours quick flash 11-13 hours pulse, flash 10-12 hours rotation 19 hours radar only | Yes / No | Good | Bad | $ | Check Price Check Price (aliexpress.com) |
| Garmin Varia RCT715 | 4 hours solid or night flash 5 hours peloton 6 hours day flash (1080p recording on) | Yes / Yes | Excellent | Excellent | $$$ | Check Price Check Price (rei.com) |
My Verdict
Buying a cycling radar was one of the best investments into my safety on a bike right after the bicycle helmet.
It increases my awareness about the cars behind me and helps me to adjust my riding style accordingly.
Based on my experience, I consider Garmin Varia RTL515 (also available at rei.com) the best cycling radar overall. It’s proven and reliable. It also has accurate multi-object detection, bright light, and good battery life. Its main weakness is its mount.
The best budget cycling radar with a taillight is the Magene L508 (also available at aliexpress.com). It’s more affordable than RTL515 and has customizable light modes, but it gives more false positives.
The best cycling radar with a camera is the Garmin Varia RCT715 (also available at rei.com). However, this is only because this is the only device that combines radar-camera-taillight functionality. Its footage quality is bad, and battery life is short.
I also tested the following radars:
Why Use a Cycling Radar?
Cycling radars can detect moving objects behind a cyclist. They visually and audibly alert him (using a bike computer or a smartphone) about them, improving his or her awareness of what’s happening behind them.
The increased awareness contributes to better safety on the roads – especially in areas with heavy traffic.
Sometimes, it’s hard to hear cars (or motorbikes) in crosswinds, so this is another scenario where bike radars are helpful.
You can prepare for the air blast while being overtaken or adjust your riding style (move to the side of the road).
Most cycling radars also have a taillight, increasing visibility in dark conditions.
How to Choose the Best Cycling Radar?
The following part explains the most important cycling radar features.
Reliability
Reliability is the most important feature you should consider when buying a cycling radar.
Cycling radars can give you one of the following four outputs:
- True positive = there is a car, and radar alerts you.
- True negative = there is no car, so the radar won’t alert you.
- False positive = there is no car, but radar alerts you.
- False negative = there is a car, but the radar won’t alert you.
You shouldn’t buy a cycling radar that gives you false negatives because it can result in catastrophic consequences.
Don’t rely 100% on the radar. Use your other senses when cycling.
Bicycle radars also differ in the number of false positives they give you. For example, false positives on Garmin Varia radars are almost nonexistent. On the other hand, Magene L508 or Bryton Gardia R300 give several false positives per ride.
Multi-object Detection
All radars offer the ability to detect multiple objects at the same time. However, again, they differ from each other.
The most accurate radars are those from Garmin. These can monitor multiple cars simultaneously (up to 8) quite accurately.
On the other hand, I’ve observed worse reliability with alternatives such as the Magene L508 and Gardia R300. They often struggle with 3 or more cars.
Type of Radar
Currently, there are three basic types of bike radars on the market:
- Without a tail light and camera
- With a tail light but without a camera
- With a tail light and camera
The first type of bicycle radar only has radar functionality. Garmin RVR315 is one example.
My favorite type (and, by far, the most popular) is the radar with a taillight but without a camera. They have the longest battery life and are relatively affordable. These include Garmin Varia RTL515, Magene L508, or Bryton Gardia R300.
Radars with a camera are a great idea but difficult to execute right. The only radar with the camera is currently Garmin Varia RCT715.
Battery Life and Charging Port
Battery life varies mainly depending on the light mode. For example, solid modes drain more battery than flash modes.
The same applies to the video recording functionality, which drains more battery.
You shouldn’t put too much weight on the battery life if you don’t mind recharging the radar often.
However, the charging port could be a deciding factor for some people. Newer radars usually have a USB-C charging port, while older units still have MicroUSB ports.
Aim for 10-plus hours of real battery life in flash mode on a new radar. Be aware that most radars don’t meet the claimed battery life. For example, my Magene L508 lasted only about 7 and a half hours in the day flash mode (instead of claimed 10 hours).
Mount
When considering a radar, you shouldn’t forget about its mount. First, it’s stability.
Bryton Gardia R300 has the most stable mount, followed by Varia RCT715. On the other side of the spectrum is the Garmin Varia RTL515 mount, which is pretty bad as it tends to slide.
The mount compatibility is another aspect to think about. Most radars have proprietary mounts, so they are incompatible with each other.
For example, if you mount Magene L508 into a Garmin mount, it will be rotated by 90°.
Additional Features
Here are other features you can consider. They shouldn’t be a deciding factor, though.
- Water and dust-proofing – cycling radars should have at least IPX7 protection. This means they can withstand rain, dust, and mud.
- Light adjustability – only Magene L508 currently offers adjustability of its light modes (brightness, length of the intervals, etc.) via a smartphone app.
