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Cycling radars become one of the most popular cycling accessories because they increase your awareness by alerting you about vehicles through your bike computer or phone.
I’ve tested most of the available cycling radars, including some you may not know, to find their pros and cons and help you decide which one to buy.
KEY TAKEAWAY
The best radar overall is the Garmin Varia RTL515. Although this is one of the first radars on the market, it is my reference 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. Feel free to buy it here without extra costs or continue reading to learn how to choose a bicycle radar, how it works, and more.
Important note: The performance of bicycle radars can change negatively after a firmware update. For example, the number of false positives may increase.
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 of at least 6 hours and be water- and dust-proof. Ideally, they shouldn’t give too many false positives. Learn more about the bicycle radar features in this guide.
Garmin Varia RTL515 (Best Cycling Radar Overall)
My Varia RTL515 rating at a glance:
Reliability 5/5 | Multi-object Detection 5/5 | Battery Life 4/5 | Brightness 5/5 | Side Visibility 5/5 | Mount 3/5 | App 4/5 | Price 3/5 | WEIGHTED OVERALL SCORE 4.3/5
More about this cycling radar scoring.
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 (8–65 lumens)
- Camera: No
- Relative detecting speed: 10 to 160 km/h (6 to 99 mph)
- App can replace bike computer: Yes
- 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. I feel like not having an arm when riding without it. To dive deeper, read my Garmin Varia RTL515 review.
Also available at rei.com, performancebike.com, and tredz.co.uk
Bryton Gardia R300L (The Best Budget Cycling Radar)
My R300L rating at a glance:
Reliability 4/5 | Multi-object Detection 4/5 | Battery Life 3/5 | Brightness 5/5 | Side Visibility 4/5 | Mount 5/5 | App 4/5 | Price 4/5 | WEIGHTED OVERALL SCORE 4.1/5
More about this cycling radar scoring.
Main Features
- False positives: Several per ride
- Affordable
- Boxy design
- Smart brake sensing
- Excellent mount
- Improves side visibility
- Decent multi-object detection
- Auto sleep feature
- Remembers the last mode used
Technical Specs
- Claimed battery life:
- 8 hours high solid (20 lumens)
- 12 hours low solid (5 lumens)
- 11 hours group ride (peloton)
- 17 hours night flash (12 lumens)
- 17 hours day flash (73 lumens)
- 24 hours radar only
- Real battery life: 11.6 hours in day flash mode
- Taillight: Yes (5–73 lumens)
- Camera: No
- Relative detecting speed: 10 to 120 km/h (6 to 74.5 mph)
- App can replace bike computer: Yes
- Connectivity: ANT+, Bluetooth
- Charging port: USB-C
- IPX7
Bryton Gardia R300L didn’t convince me of its value at first. However, this was because I received a demo unit and not the final version. However, I had the opportunity to test the production version as well, and it is worthy of inclusion in this selection.
The Gardia R300L has the nicest design, in my opinion, and also improves visibility from the side thanks to the side LEDs. Like other non-Varia radars, the Gardia is limited to a maximum relative detection speed of 120 km/h. This can be low on some road sections.
On the other hand, it has the sturdiest mount that doesn’t slip on the seatpost when riding on cobbles. It can also switch itself to sleep mode to save battery. It also remembers the last mode used and alerts those behind you when you start braking. It is relatively accurate, but like the L508, it will give a few false positives per ride.
Lastly, I want to mention the Bryton Gardia smartphone app, which is simple and intuitive and will allow you to replace the bike computer. Read my Bryton Gardia R300L review for more in-depth info.
Garmin Varia RCT715 (Best Cycling Radar with Camera)
My RCT715 rating at a glance:
Reliability 5/5 | Multi-object Detection 5/5 | Battery Life 1/5 | Brightness 5/5 | Side Visibility 5/5 | Mount 3/5 | App 3/5 | Price 2/5 | WEIGHTED OVERALL SCORE 3.8/5
More about this cycling radar scoring.
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 (8–65 lumens)
- Camera: Yes
- Relative detecting speed: 10 to 160 km/h (6 to 99 mph)
- App can replace bike computer: 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. Unfortunately, Garmin’s execution 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 car license plates.
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 tredz.co.uk
Magene L508 (Most Customizable Cycling Radar)
My L508 rating at a glance:
Reliability 4/5 | Multi-object Detection 4/5 | Battery Life 2/5 | Brightness 4/5 | Side Visibility 2/5 | Mount 4/5 | App 4/5 | Price 4/5 | WEIGHTED OVERALL SCORE 3.5/5
More about this cycling radar scoring.
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
- Safety tether included
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 (6–40 lumens)
- Camera: No
- Relative detecting speed: 10 to 120 km/h (6 to 74.5 mph)
- App can replace bike computer: Yes
- 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.
*These false positives are less frequent after firmware updates.
You can increase its light brightness in exchange for a shorter battery life. It also struggles with multi-object detection, as it is less accurate than Varia. If you want to save money, choose L508 instead of RTL515.
Read my Magene L508 review for more in-depth info.
Also available at aliexpress.com
iGPSport SRTL SR30 (Best Battery Life Cycling Radar)
Main Features
- False positives: Many per ride
- More expensive than other Asian alternatives
- Smart brake sensing
- Decent multi-object detection
- Improves side visibility
- Auto sleep feature
- Safety tether included
- Remembers the last mode used
- Unstable mount
- A short duration of the light pattern change when overtaking
Technical Specs
- Claimed battery life:
- 8 hours solid
- 12 hours flash
- 15 hours breathing
- 18 hours night flash
- 20 hours radar only
- Real battery life: 16.9 hours in flash mode
- Taillight: Yes (6–65 lumens)
- Camera: No
- Relative detecting speed: 10 to 120 km/h (6 to 74.5 mph)
- App can replace bike computer: Yes
- Connectivity: ANT+, Bluetooth
- Charging port: USB-C
- IPX7
The iGPSport SR30 is the battery life champ of cycling radars. Despite its claimed battery life is 12 hours in day flash mode, I squeezed 16.9 hours from it! This is also thanks to the auto-sleep feature.
Compared to the Magene L508, it also has LEDs on the sides, which increases side visibility, especially in the dark.
The SR30 isn’t as accurate at tracking multiple cars as the Varia, and it also gives more false positives. Unfortunately, after a firmware update, the number of false positives increased after one firmware update, making it less appealing.
It’s also a shame that it doesn’t change the flashing mode for the whole time you’re overtaking, but only for a few seconds. Its mount also tends to slip on the seatpost, similar to the Varia mount.
Another limitation is the maximum relative detection speed of only 120 km/h. Vehicles going faster than that are not detectable by this radar. However, the radar detected all vehicles within this limit during my testing.
Read my iGPSport SRTL SR30 review for more in-depth info.
| Cycling Radar | Battery Life¹ | Charging Port | Taillight / Camera | Mount Stability | Lumens | Buy | Reliability | Multi-object Detection | Battery Life | Brightness | Side Visibility | Mount | App | Price | Weighted Score |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Garmin Varia RTL515 | 6-16 hours day flash | Micro USB | Yes / No | Bad | 8–65 | Check Price Check Price (rei.com) | 5 | 5 | 4 | 5 | 5 | 3 | 4 | 3 | 4.3 |
| Bryton Gardia R300L | 4-19 hours radar only | USB-C | Yes / No | Excellent | 5–73 | Check Price | 4 | 4 | 3 | 5 | 4 | 5 | 4 | 4 | 4.1 |
| Garmin Varia RCT715 | 4-6 hours day flash (1080p recording on) | USB-C | Yes / Yes | Excellent | 8–65 | Check Price Check Price (rei.com) | 5 | 5 | 2 | 5 | 5 | 4 | 4 | 1 | 4.0 |
| Magene L508 | 4-19 hours radar only | USB-C | Yes / No | Good | 6–40 | Check Price Check Price (aliexpress.com) | 4 | 4 | 2 | 4 | 2 | 4 | 4 | 4 | 3.5 |
Scoring on a scale 1-5 where 5 is the best.
¹Depends mainly on the used light mode and the outside temperature.
Updated: April 4, 2025
Which Radars to Avoid?
Below are the radars I recommend avoiding. They usually give too many false positives or sometimes even false negatives.
Tutuloo W100
I also tested the TUTULOO W100 radar, which gave me a false negative. So, I decided not to include it among the best ones.
My Tutuloo W100 rating at a glance:
Reliability 1/5 | Multi-object Detection 3/5 | Battery Life 5/5 | Brightness 2/5 | Side Visibility 1/5 | Mount 1/5 | App 3/5 | Price 5/5 | WEIGHTED OVERALL SCORE 2.5/5
More about this cycling radar scoring.
Trek CarBack
The Trek CarBack underdelivers in some aspects, like detection distance and accuracy. It never gave me a false negative (or false positive), but it is inconsistent in its detection distance. The firmware updates may improve it, but considering its price, I don’t recommend it. Buy Varia RTL515, which costs the same but is more reliable instead. Read my CarBack review for more details.
My CarBack rating at a glance:
Reliability 4/5 | Multi-object Detection 4/5 | Battery Life 3/5 | Brightness 5/5 | Side Visibility 1/5 | Mount 2/5 | App 3/5 | Price 3/5 | WEIGHTED OVERALL SCORE 3.2/5
More about this cycling radar scoring.
Magicshine R300
Another radar I recommend avoiding is the Magicshine R300. I have tested three different iterations in total, and based on my feedback, Magicshine has decided to push back the launch date. I appreciate this immensely. Unfortunately, despite their best efforts, they were unable to optimize it. So, what’s the problem? The R300 simply gives too many false positives, so it can’t be relied upon, and over time, you learn to ignore it.
My R300 rating at a glance:
Reliability 2/5 | Multi-object Detection 4/5 | Battery Life 2/5 | Brightness 5/5 | Side Visibility 5/5 | Mount 5/5 | App 3/5 | Price 4/5 | WEIGHTED OVERALL SCORE 3.8/5
More about this cycling radar scoring.
iGPSport SR30
When I tested the iGPSport SR30 for the first time back in 2024, it performed similarly well as the Magene L508 or the Bryton Gardia R300L. It has one of the best battery life of all radars. Unfortunately, after the 1.1 firmware update, it started to give too many false positives. I also experienced issues with pairing and freezing.
My SR30 rating at a glance:
Reliability 2/5 | Multi-object Detection 4/5 | Battery Life 4/5 | Brightness 5/5 | Side Visibility 5/5 | Mount 3/5 | App 4/5 | Price 3/5 | WEIGHTED OVERALL SCORE 3.6/5
More about this cycling radar scoring.
My Verdict
Buying a cycling radar was one of the best investments in my safety on a bike, right after the bicycle helmet. It increases my awareness about the cars behind me and helps me 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 reliable and has accurate multi-object detection, bright light, good side visibility, and battery life. Its main weaknesses are its mount and MicroUSB charging port.
The other radars always have at least one stand-out feature. For example, Bryton Gardia R300L has the sturdiest mount, Varia RCT715 has the camera, and Magene L508 is easily customizable.
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 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 R300L give several false positives per ride.
Multi-object Detection
All radars can detect multiple objects simultaneously. However, again, they differ from each other. The most accurate radars are those from Garmin. These can track up to 8 quite accurately.
On the other hand, I’ve observed worse reliability with alternatives such as the Magene L508 and Gardia R300L. 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 R300L.
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 R300L 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.
Mount compatibility is another aspect to consider. 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°.
Maximum Relative Detection Speed
The maximum relative detecting speed determines how fast the radar will be able to detect moving vehicles.
For example, if the speed is 120 km/h (74.5mph), and you are traveling at 30 km/h (18.6mph), and a car traveling at 160 km/h (99mph) overtakes you, the radar will not be able to detect it.
Most radars have this speed between 10–120 km/h (6–74.5mph). Garmin Varia series radars have a higher range, 10–160 km/h (6–99mph).
Most radars also won’t detect vehicles traveling the same speed as you do.
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.
Cycling Radars FAQ
Recent Updates
- Mar 3, 2025: Improved copy and updated the info on a higher number of false positives of the iGPSport SR30 radar.
- Apr 4, 2025: Moved the iGPSport SR30 to the “Avoid” section after another retesting. It gives too many false positives, and sometimes even freezes.
Nice review, but an important feature of every radar device was not mentioned: the number of lumens of the taillights. This is information I need to decide if a taillight is appropriate for my use. Less than 150 lumens doesn’t cut it for visibility on a bright, sunny day. The lumen value should be included in the “Technical Specs” section of every device reviewed.
Thanks for your feedback, Greg. I’ve updated the table and added the number of lumens to the article. 🙂
– Petr
Great review! I appreciate the detailed comparisons and the recommendations based on actual tests. It’s super helpful to see which models perform best in different conditions. I’m definitely going to consider the top picks for my next ride. Thanks for sharing!
Thanks. I appreciate that. 🙂
This is a topic I’ve been curious about. Thanks for the detailed information.
You are welcome, John. 🙂
Great review and write up on the various radar unit. I’ve been cycling for many year and currently use a helmet mirror. I’m looking for an added layer of protection while on the road. The information you provided will make it much easier to decide on which unit to purchase.
Hi Charles,
Thank you. I’m glad you find it helpful. 🙂
– Petr
Great breakdown of cycling radars! I appreciate the detailed comparisons and the pros and cons of each device. It’s so helpful to know which ones to avoid. Looking forward to trying out the top recommendations!
Thank you, I’m glad you find it helpful. 🙂
Thanks for the reviews but I notice you did not include the TREK Carback. Is there a reason why or you have not tested it out as yet?
Hi Thomas,
Thank you. 🙂
Yes, it was very underwhelming, read my review for more details: https://www.cyclistshub.com/trek-carback-radar-review/.
– Petr
Ahoj Petr. What about Cycplus L7? I bought it a month ago from mtbiker.sk – just for fun as it was cheap (91€) and using it all the time since then. Varia is on a break for now 🙂 Battery life is great (could be even as they say on the box and definitely longer than Varia), there are almost no false positives (basically same as Varia) and zero false negatives so far. I connected it without any issues to Edge 530, Fenix 6x Pro and Magene C506. It has same mounting system like Garmin which is great for me to move it from one bike to another. It is not that bright as Varia, but again bright more then enough. Looks very promising for now.
Hi Ivan,
Cool! What about false positives? I have ordered it today. 😀
– Petr
I’m always mixing these false pos/neg 😂
But I think I wrote it right. Sometimes it happens that detects car even if it’s not there and it also detects cars that are coming from side roads (it’s got wider angle or detection). Ut even detects pedestrians… Also Varia always detects itself in the elevator mirror and L7 doesn’t do that. I rode with it for approx. 800km and so far it has never missed the car – which is the most important. Also very cool feature is this braking function – it works great. I also tested water resistance… I was once coming back on a muddy day from Little Carphatians in Bratislava and I stopped to wash the bike in the high pressure car wash station without de-attaching L7. It survived 😁
Can’t wait for you to test it on YT.
Awesome, that sounds great because I’m sick of poor radars (have you seen my Magicshine R300 review? :-D).
Yep, I saw them all and I really like your channel. And this is the reason why I wrote here 🙂 I was actually deciding between Magene L508 and this one as a backup for Varia. There were many reviews for Magene with mixed outcomes, however only few for Cycplus L7 but all positive, so I risked.
Cool, thank you, I appreciate it. Let’s see how my L7 performs. 🙂 Varia is on sale now, so I would buy it.