There are several reviews out there on Garmin's Varia RTL510, but none really hits on its synergistic advantages. This review is based on my own experiences with this device and explains why you need one as long as you don’t ride in the city or congested areas.
My interest in the RTL510 started when I was looking for a good daytime tail light. Most riders' interest is piqued by the radar function, which is really cool, but the RTL510 truly synergizes with the Garmin GPS to form an effective safety tool. I ride on rural two-lane roads that don’t have much of a shoulder and do have a lot of rolling hills that can obscure your vision. I have been using one of those geeky mirrors that attaches to my sunglasses, which is effective but requires you to keep tilting your head like you are having a seizure to see at different angles. In addition, the wind is often too loud for me to hear cars coming up behind.
Garmin released its first iteration of the radar a couple years back; it was good, but there was room for improvement. It mounted sideways, which isn't very aerodynamic, and there were some quirks. Earlier this year, Garmin released this version, and it looks like it got things right. The new Garmin Varia RTL510 retails for $199. At first I thought, "That’s nice, but it’s too expensive." (And most of you are probably thinking the same right now.) What I can attest to is that it is a game changer. After my first ride, I couldn’t believe just how useful and effective the RTL510 was.
If you own a Garmin GPS already, this is a no-brainer, as it seamlessly integrates with your device. I have a Garmin 1000, and it took about 5 min to set up. If you don't have a Garmin GPS, or don't want one, you can buy a bundle that includes the radar unit and a handlebar readout for $299 -- but for that extra $100, you could also buy a lower-level GPS and have it all. (Can you really ride without knowing your heart rate? I can't . ) Wahoo users are out of luck, as they don't plan on supporting the device.
The Varia mounts to the seat post with a heavy-duty rubber band. A few different mount bases are supplied, including one for aero posts. Although I haven't had any issues with this design, I think it is the weak point of the 510. I bought a hard-mount unit from Garmin because I have concerns that, over time riding on chip and seal, the band will stretch or slip off the notched base (click here to see). The unit needs to be mounted above the back tire. According to Garmin, the higher, the better, but when my unit is only a couple of inches above the tire on my Emonda, it is just as effective as when I have it up higher on my Moots.
Yes, it’s a real radar! It very effectively detects vehicles from at least 150 yd behind you. That in itself is super cool and worth the price. Yep, it’s also a very bright tail light with a light pattern that gets attention from about a mile away during the day (with other settings as well). But it's the synergy of these two features that makes the Varia RTL510 even more of a valued piece of equipment and information center. It isn't only a radar and a light: the Garmin can take over your light management. It also shows you where cars are, not just, "Hey, something's behind you."
The light is bright, with a daytime setting of 65 lumens. This is plenty bright for day, but what’s actually more important is the flash pattern. The disruptive pattern is an irregular flash, which studies show is more effective in getting the attention of drivers and thus more important than the brightness. When no cars are present, the light stays in a standard pattern; once cars are detected, the light pattern changes, drawing more attention to you. There are other settings, but I think this one is best for road biking.
It also has lights on the side of the unit (see below). Settings include auto on and off. Turn on the RTL510, and it links to your Garmin GPS (there is a small blue light that shows it's linked), the light will come on then go off. When you start your Garmin GPS (you can choose either power on or start of a ride), the light turns on. This saves battery life, and since you will forget to turn it on half the time, it’s a handy feature. Plus, when you stop or take a break, the light goes off so it isn’t blinding you or your friends. You do need to have the auto pause setting on your Garmin GPS enabled for this to work.
I’ve used it for over 5 hr without recharging; it will supposedly go as long as 15 hr, but I doubt that. Recharging is simple; it plugs into the same charging USB as the Garmin 1000. It takes a couple of hours to charge, and you can manage firmware updates through Garmin Express.
The radar display on the Garmin is simple yet very effective; photos below show the process. When it is connected to the Garmin GPS, you see a small symbol in the upper-right-hand corner that looks like a spider web. When the unit detects a vehicle, you hear a single beep (it doesn’t incessantly beep, which would annoy the crap out of me). The screen shows amber bands on both sides, and a small dot appears at the bottom; both of these indicators can be tweaked in the settings, eg, the dot can be put on the right or left side of the display.
As the vehicle approaches, the indicator rises from the bottom to the top. If the vehicle is approaching rapidly, it turns red. I have tested this: cars traveling at 35-40 mph show as amber; on a stretch of highway with a 65-mph speed limit, they turn red. Once the vehicle passes, the indicator turns green, then goes clear. The display will show multiple vehicles, which is important. At times it will pick up other bike riders if they are just to your left at the correct distance. I don’t mind that, so I know if someone is coming up on me or riding on my wheel.
On my first ride, I very quickly came to trust the RTL510. It made riding on narrow roads much less stressful. I ride in a low position with my head low, and I have to keep looking behind me to monitor traffic. With the RTL510, I don’t need to continually tilt my head to try to see behind me. In fact, after a few rides, I am trusting the device and only look behind me when moving across a lane to make a turn. It’s amazingly accurate and gives you plenty of time to plan if needed, but the little blip on the screen is really helpful in showing you where a vehicle is and how fast it’s closing on you.
So far I have experienced very few false alarms. When I go down the backside of a roller, if there’s a house at the top of the roller, it thinks there’s something behind me. Don’t ask me why. It only happens in one specific spot, and it happens every time. Go figure. I have also noticed that if cars are too close together, the sensor will not distinguish both cars, so be cautious and wait until the unit goes green.
Yes, it’s expensive. But when you consider the synergy of the light and the radar, the 510 is a highly effective safety device. I honestly can’t imagine riding without it now.
Here is a series of images that show how a vehicle is displayed on the screen. Notice how the blip appears at the bottom of the screen when the vehicle is about 125 yd back (it will accurately detect a vehicle at about 150 yd). The screen turns amber. The second shows the vehicle as it gets closer, and the third shows that the vehicle has passed and there are no other vehicles.
The Garmin Varia RTL510 on my bike:
My interest in the RTL510 started when I was looking for a good daytime tail light. Most riders' interest is piqued by the radar function, which is really cool, but the RTL510 truly synergizes with the Garmin GPS to form an effective safety tool. I ride on rural two-lane roads that don’t have much of a shoulder and do have a lot of rolling hills that can obscure your vision. I have been using one of those geeky mirrors that attaches to my sunglasses, which is effective but requires you to keep tilting your head like you are having a seizure to see at different angles. In addition, the wind is often too loud for me to hear cars coming up behind.
Garmin released its first iteration of the radar a couple years back; it was good, but there was room for improvement. It mounted sideways, which isn't very aerodynamic, and there were some quirks. Earlier this year, Garmin released this version, and it looks like it got things right. The new Garmin Varia RTL510 retails for $199. At first I thought, "That’s nice, but it’s too expensive." (And most of you are probably thinking the same right now.) What I can attest to is that it is a game changer. After my first ride, I couldn’t believe just how useful and effective the RTL510 was.
If you own a Garmin GPS already, this is a no-brainer, as it seamlessly integrates with your device. I have a Garmin 1000, and it took about 5 min to set up. If you don't have a Garmin GPS, or don't want one, you can buy a bundle that includes the radar unit and a handlebar readout for $299 -- but for that extra $100, you could also buy a lower-level GPS and have it all. (Can you really ride without knowing your heart rate? I can't . ) Wahoo users are out of luck, as they don't plan on supporting the device.
The Varia mounts to the seat post with a heavy-duty rubber band. A few different mount bases are supplied, including one for aero posts. Although I haven't had any issues with this design, I think it is the weak point of the 510. I bought a hard-mount unit from Garmin because I have concerns that, over time riding on chip and seal, the band will stretch or slip off the notched base (click here to see). The unit needs to be mounted above the back tire. According to Garmin, the higher, the better, but when my unit is only a couple of inches above the tire on my Emonda, it is just as effective as when I have it up higher on my Moots.
Yes, it’s a real radar! It very effectively detects vehicles from at least 150 yd behind you. That in itself is super cool and worth the price. Yep, it’s also a very bright tail light with a light pattern that gets attention from about a mile away during the day (with other settings as well). But it's the synergy of these two features that makes the Varia RTL510 even more of a valued piece of equipment and information center. It isn't only a radar and a light: the Garmin can take over your light management. It also shows you where cars are, not just, "Hey, something's behind you."
The light is bright, with a daytime setting of 65 lumens. This is plenty bright for day, but what’s actually more important is the flash pattern. The disruptive pattern is an irregular flash, which studies show is more effective in getting the attention of drivers and thus more important than the brightness. When no cars are present, the light stays in a standard pattern; once cars are detected, the light pattern changes, drawing more attention to you. There are other settings, but I think this one is best for road biking.
It also has lights on the side of the unit (see below). Settings include auto on and off. Turn on the RTL510, and it links to your Garmin GPS (there is a small blue light that shows it's linked), the light will come on then go off. When you start your Garmin GPS (you can choose either power on or start of a ride), the light turns on. This saves battery life, and since you will forget to turn it on half the time, it’s a handy feature. Plus, when you stop or take a break, the light goes off so it isn’t blinding you or your friends. You do need to have the auto pause setting on your Garmin GPS enabled for this to work.
I’ve used it for over 5 hr without recharging; it will supposedly go as long as 15 hr, but I doubt that. Recharging is simple; it plugs into the same charging USB as the Garmin 1000. It takes a couple of hours to charge, and you can manage firmware updates through Garmin Express.
The radar display on the Garmin is simple yet very effective; photos below show the process. When it is connected to the Garmin GPS, you see a small symbol in the upper-right-hand corner that looks like a spider web. When the unit detects a vehicle, you hear a single beep (it doesn’t incessantly beep, which would annoy the crap out of me). The screen shows amber bands on both sides, and a small dot appears at the bottom; both of these indicators can be tweaked in the settings, eg, the dot can be put on the right or left side of the display.
As the vehicle approaches, the indicator rises from the bottom to the top. If the vehicle is approaching rapidly, it turns red. I have tested this: cars traveling at 35-40 mph show as amber; on a stretch of highway with a 65-mph speed limit, they turn red. Once the vehicle passes, the indicator turns green, then goes clear. The display will show multiple vehicles, which is important. At times it will pick up other bike riders if they are just to your left at the correct distance. I don’t mind that, so I know if someone is coming up on me or riding on my wheel.
On my first ride, I very quickly came to trust the RTL510. It made riding on narrow roads much less stressful. I ride in a low position with my head low, and I have to keep looking behind me to monitor traffic. With the RTL510, I don’t need to continually tilt my head to try to see behind me. In fact, after a few rides, I am trusting the device and only look behind me when moving across a lane to make a turn. It’s amazingly accurate and gives you plenty of time to plan if needed, but the little blip on the screen is really helpful in showing you where a vehicle is and how fast it’s closing on you.
So far I have experienced very few false alarms. When I go down the backside of a roller, if there’s a house at the top of the roller, it thinks there’s something behind me. Don’t ask me why. It only happens in one specific spot, and it happens every time. Go figure. I have also noticed that if cars are too close together, the sensor will not distinguish both cars, so be cautious and wait until the unit goes green.
Yes, it’s expensive. But when you consider the synergy of the light and the radar, the 510 is a highly effective safety device. I honestly can’t imagine riding without it now.
Here is a series of images that show how a vehicle is displayed on the screen. Notice how the blip appears at the bottom of the screen when the vehicle is about 125 yd back (it will accurately detect a vehicle at about 150 yd). The screen turns amber. The second shows the vehicle as it gets closer, and the third shows that the vehicle has passed and there are no other vehicles.
The Garmin Varia RTL510 on my bike: