Three months ago, I acquired the Garmin Varia RTL510 bike radar and rear light - second-hand, only for $134 from AliExpress.

Almost immediately after receiving it, I conducted a short test and review, which you can read here:

Garmin Varia RTL510 Bike Radar and Rear Light - First Test and Review

The reason I sit down and write this article in the blog today is that after three months of almost daily use, the bike radar stopped working ...

You can read why it stopped working and how I managed to fix it fortunately in the short review below.

Tests and Impressions of Garmin Varia RTL510 Bike Radar and Rear Light

The Garmin Varia RTL510 bike radar is a super valuable part of my bike equipment, Pips.

I won't leave without it anymore!!! Firmly!

These are my impressions of the radar and rear light Garmin Varia RTL510 after 3 months of active use.

I am extremely satisfied and highly recommend it to any colleague!

The radar is very useful when riding in the wind or at higher speeds on a flat road, not to mention for even faster descents.

When riding at high speeds, the wind is whistling in your ears and you usually hear almost nothing, not to mention the cars coming from behind.

The radar is also very useful on less busy intercity and intercountry roads.

It often happens to me that a car behind me takes quite a while to pass and in such a moment I start driving closer to the middle of the road ... and then a car comes from behind out of nowhere.

Yes, definitely the price of the radar is not low at all. The price of the new model radar RTL515 is about 360 BGN at Decathlon.

For me personally, the price of $140 for a second-hand radar was quite advantageous, BUT buying a radar from Aliexpress has one very big "BUT"!

YOU DO NOT HAVE WARRANTY! ... and this is quite important, as you will see from the shared experience in the article below.

Garmin Varia RTL510 Crash & Fix

A few weeks ago, at the end of the rainy and extremely cold June, the Shipka 300 brevet took place.

I didn't manage to participate in this brevet because I had to work that day, but due to the heavy rain that poured early on Saturday morning, my day unexpectedly freed up at the last minute!

I see in our Telegram group that my colleagues who are doing the brevet are still in the area of Gabrovo, and I decided to ride with them today through Beklemeto. We loaded Pips in the car and in no time we reached Trojan.

The rain had stopped for the moment!

I started with Pips and after a while I saw a lone rider coming towards me from Trojan - it turned out to be Lazar. I went up with him to climb Beklemeto together.

It was raining throughout the whole way up to the pass. Sometimes it was a light rain, sometimes it was heavy and there were also some sections with rivers on the road.

Overall, it rained almost constantly on our way up, and I DIDN'T bring mudguards, so I became a water vortex in no time.

I rode with Lazar to the top, then went down 5-6 km to the Panorama restaurant for a mushroom soup, and then climbed up to the top two more times with other brevet colleagues.

Heavy rain was pouring on us on the top of Beklemeto itself, sometimes it stopped, sometimes it started again and so on throughout the whole day... :)

Throughout the day, my radar worked perfectly and without any problems. It correctly displayed the cars coming from behind on time.

By the end of the day, with completely wet clothes that had been wrung out and dried several times, I started to descend towards my car parked a little before the end of Troyan.

As I was driving around a bend, suddenly I found myself under a waterfall of icy water - such a strong downpour had not rained down on us with Pips until then!

From the sky, a powerful icy cold waterfall suddenly started pouring down.

It's a good thing I was near the shelter opposite the fountain in the middle of the climb to the top, so after 5-10 minutes, I managed to hide in the downpour, but Pips and the radar were left in the rain ... :(

After some time, the rain finally stopped and Pips and I continued down. The road had turned into a river :)

You can get an idea of that last rain from the video below:

https://www.youtube.com/watch?v=vjZUZm5Ggg8

I am describing all this driving and getting wet in such detail to give you a real impression of how much water was poured down on the Garmin Varia RTL510 radar on that day!

The radar is IPX7 rated for water resistance.

I drove all day calmly in the rain and didn't think about the radar being directly exposed to both the downpour and the water thrown back on it from the rear tire. At that time I didn't even have a mudguard...

BUT I overlooked the fact that my radar is second-hand and may have been opened for some reason and have compromised water resistance...

The next day we were driving again with Pips on the Devetashko Plateau and then the radar started to malfunction... And I behaved totally irresponsibly towards all this! :(

Initially, the radar started signaling for cars behind me when there were no cars at all.

I think it even signaled at one point for missing cars, and then DID NOT signal for an actually incoming car.

Complete absurdity... but I know that according to the specification, the radar is IPX7 for water resistance and I DID NOT even consider the rainy weather from the previous day.

I stopped and restarted the radar - no change, the radar continued to behave INADEQUATELY.

I thought maybe the Garmin software had malfunctioned?

I deleted the radar and the rear light from the list of available sensors on my Garmin Edge 530 bike computer.

Then I added the radar again... no change.

I saw that the radar battery was almost dead, so on top of everything, I grabbed it and plugged it into the power bank I was carrying to charge it... ?!?

I did some completely inadequate things this afternoon when the radar failed for the first time and started making some absurd errors and problems.

Only the next day, I noticed drops of condensation inside the body through the radar glass - moisture... clearly... :(

I took the hair dryer and "dried" the radar several times.

I didn't heat it up too much to a high temperature, but I heated it up a few times and after each time, I let it cool down, hoping that the moisture inside the radar would quickly evaporate.

I did a circle after drying, but unfortunately there was no change.

The radar function in Garmin Varia RTL510 completely failed to work the next day.

Well, at least the Smart Lights rear light function still worked.

Horrible! I got so used to this radar over the past 3 months.

It's so cool!!! And because of my complete stupidity, it doesn't work anymore!

:( :( :(

After I returned from that ride, I left the radar in the sun for several days in a row.

It was quite warm days with a lot of sunlight. I hoped that the moisture would finally evaporate.

Overall, the effect after drying for several days in the sun was as follows: the radar function hardly worked, the radar sensor did NOT connect to my Garmin computer via ANT+ protocol.

But sometimes when I drove through the potholes here and there along the road on the Devetashko plateau, the radar would briefly turn on, then the connection would be lost again, but the taillight function was still okay.

That's how I used the damaged and non-working Garmin Varia RTL510 only as a rear light for a few days.

I started to wonder what I would do... would I buy a new radar or what... I got used to the radar, but I definitely didn't want to spend 360 lv for a new one from Decathlon!

Meanwhile, I lost the rearview mirror on Pips' handlebar somewhere. What a nightmare... :)

I drove like that for a few days until at one point, the radar started to appear temporarily and stayed connected to the computer for a longer period of time.

Then, after passing through a pothole, the connection with the radar would disappear again, and then it would turn on again after an unevenness, etc., but without any direct dependency.

In the evening, when I was charging it, I was impressed that the green flashing LED on the side of the radar, which shows if it's charging and if the battery is fully charged, started flashing in red, not green.

Such anomalies...

Fortunately, after a few days of hardship, the radar function of the Garmin Varia RTL510 started to work much more stable!

Yay! Awesome!... :)

Yes, yes... but No!

One morning after a routine radar recharge, I noticed that the LED indicating the battery charging status was no longer lit, neither green nor red.

The radar had been fully charged in the morning, but the battery charging LED had completely stopped glowing.

However, the radar function had returned completely, and everything started working perfectly and correctly as before getting wet.

I was overjoyed! ...

Yes, I was overjoyed until I found out that the radar was no longer charging when I connected it to the charger ?!?

Ufff ... another problem ... :(

I tested different cables, different chargers. No, no, and NO!

My battery was slowly dying. I had a 24-hour Flash Velochio 2021 ride scheduled for Friday ... and the radar battery was slowly draining ... and so on.

On Thursday morning, before the ride, I decided that I would not leave things as they were. I would not abandon the radar!

I would open the radar to see if I could save it ... and if necessary, I had decided to run cables directly from the battery and charge the 3.6 volt battery directly.

Keep in mind that the MicroUSB charger supplies 5 V, which then decreases to 3.6 V on the radar board to charge the battery.

Fortunately, I had purchased a very good charger from AliExpress years ago that can adjust the voltage it supplies.

But how do I disassemble this Garmin Varia RTL510?!?!?!?!

Fortunately, I came across this forum post on the Internet with a detailed guide and pictures on how to disassemble the Garmin Varia RTL510!

I looked at the pictures, carefully read the instructions, and finally decided to do it.

I have no other alternative, I will disassemble my radar and try to revive it!

Garmin Varia RTL510 FIX

I carefully placed the radar on a soft surface.

I fastened it very lightly, and from the inside, I started to hear a slight cracking sound - the glue that held the two parts together on the edge began to crack here and there.

I carefully heated the top part of the radar. Be especially careful and do not overheat it, as the plastic easily starts to melt...

On the grinder in my workshop, I sharpened an old screwdriver very well, with which, step by step, very slowly and carefully, I started to press the spot shown in the pictures above.

I followed the instructions from the forum and the pictures precisely.

A slight cracking sound began to be heard along the line where the two parts were glued together as a result of the pressure, and little by little, the cover began to come off.

Clearly, the two parts were glued together with some kind of strong adhesive, and I'm not sure if heating the casing played any role in separating the cover.

I turned it over and after a minute the cover completely detached.

Hooray! :)

Inside, I found numerous whitened spots on the plastic casing of the radar and whitened spots from oxidation (corrosion) in places on the circuit board ... :(

Thanks to this article about the NOT working MicroUSB port on the Garmin Edge 800, I realized that I needed to thoroughly clean all of these white spots of corrosion on the board and pins.

The board needed careful and high-quality cleaning.

In the case of this colleague's problem with the NOT working MicroUSB port on the Garmin Edge 800, after cleaning the corrosion, the USB port started working normally.

I took pure alcohol and a few cotton swabs and carefully cleaned the circuit board on both sides.

Then I dried the board with a hairdryer just in case.

Afterwards, I cleaned it again and dried it another 2-3 times.

There were no white spots of oxidation or corrosion left anywhere on the board.

The moment of truth had arrived!

Did all of this have any effect?

I carefully reassembled the construction and plugged in the power cable.

The LED indicator showing if the radar battery is charging still does NOT work!

:( :( :(

The radar showed no signs of life...

Then I remembered that I have a device for measuring the voltage and amperage of USB chargers, and I plugged the radar into it to charge.

And yes!

The charging port now works! Hooray! :) :) :)

For now, I decided NOT to attach the radar, I just tightened it with a pigtail.

I wanted to test it for a few days to see how it would work before attaching it.

The next day was the start of the 24-hour Flash Velochio 2021 brevet.

I used the radar throughout the time, and after 13-14 hours, I had to recharge it.

All functions work without any false or wrong car alarms.

Everything is perfect again!

Hooray!

As a result of the rain in Beklemeto, the only thing that still does not work is the LED indicator for battery charging.

CONCLUSIONS

- Although Garmin Varia RTL510 is waterproof with an IPX7 rating, I will keep it from getting wet;

- For future rain and especially in heavy rain, I have prepared a transparent, dense, zip-closed bag to cover the radar for additional insulation;

- If the radar gets wet again, I will NOT use it, I will turn it off directly and dry it 5-6 times with a hairdryer;

- If the wetting is more serious, I will open the box and carefully clean and dry the board with a hairdryer.

 - The Garmin Varia RTL510 bike radar is actually quite easy to install.

:) :) :)

Bike Radar and Rear Light Garmin Varia RTL510 - First Test and Brief Review