The Serfas Thunderbolt Tail Light offers a quick, easy and affordable way to stay safe on your bike by making you clearly visible from behind. It is one of the brightest bike tail lights available, yet costs less than $40. Here is my full review!
Bright Light at a Budget Price
The Serfas Thunderbolt bike tail light is a budget bike tail light that attaches with silicone stays to pretty much any part of your bike.
No Tools Required
You don’t need tools – you just snap the stays in place. I usually put it on my rack, and it attaches very securely. Unlike many other bike lights, it does not move around, so that you get to work and find you have been shining your light onto the ground the whole time! And the easy mounting system means you can fix it to any part of your bike, or even your backpack. This makes it ideal for those who have more than one bike.
The stays and charger have remained the same over many generations of this bike light, which I always like. I hate to be forced to buy a new light because I have lost one little rubber stay. By the way, if you do lose one of these bands, you can replace them via the Serfas website.
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Pros of the Serfas Thunderbolt Bike Tail Light
- Like all good bike lights, the Serfas Thunderbolt (UTL-6) bike taillight could save your life one dark night (or winter morning). This alone justifies spending a little under $50 on it. Plus, it comes in a range of seven different really fun colors, so you can choose a color to match your bike!
- The Serfas Thunderbolt is extremely bright, thanks to its 30 micro-LEDs strip. I am sure it makes the back of my bike visible for at least half a mile. On the other hand, it is small enough that cyclists behind you are not blinded.
- It produces 35 lumens of pure red light.
- It’s very light (50 grams).
- It has four modes: high beam steady; low beam steady; high blink and low blink. Of course, the battery lasts way longer on the blinking modes. I like the high beam steady, which unfortunately eats up the battery very fast (less than 2 hours).
- It is easy to switch off – just hold down the power button for several seconds.
- The USB charger socket is universal, not proprietary – for example, you can use a Garmin bike computer USB cable to charge this light via your computer.
- The silicone mounting bands make it a cinch to mount this light – it just takes seconds, and no tools required!
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Tips for Using your Serfas Thunderbolt Tail Light
- Note that the battery will last only about 2 hours with the light on steady beam. It lasts much longer on blinking mode, and is probably more visible that way too. However, I have had so much feedback from readers who find flashing lights disturbing, that I now keep my lights on steady beam all the time. (Read all about When to Use Flashing Bike Lights here.)
- The light comes with just a USB cable to charge it. It will charge much faster direct from the socket using an Apple type plug, than if you plug it into a computer. Still, the charging time is 3.5 hours, so remember to plug it in as soon as you get home!
- To avoid losing the mounting bands, I have developed a tidy habit of putting these into the top pocket of my cycling jacket the minute I remove the light from my bike, so they are safe and handy.
The Serfas Thunderbolt Bike Tail light attaches easily to your seat post or any other part of your bike or even backpack or pannier. I attach mine to the back of my rack.
Features of the Serfas Thunderbolt Tail Light
- Light silicone body
- 30 micro-LEDs strip
- 35 lumens of pure red light
- Modes: 1.75 hours (high beam); 7 hours (low beam); 3 hours (high blink); 9.5 hours (low blink)
- Unique mounting system that allows for endless mounting possibilities
- Highly Water resistant (I have used it in floods, and never had a problem)
- Weight: 50 grams
- Comes in 7 different color options
- Rechargeable Lithium Polymer battery
- If you lose the silicon bands, you can replace them via the Serfas website
- They last forever – they really are super tough. I have had these lights for years and they never seem to die
Bottom Line on the Serfas Thunderbolt Tail Light
The Serfas Thunderbolt Tail Light offers a quick, easy and affordable way to make yourself clearly visible from behind. It is way brighter than about 90% of the bike tail lights I see on the road. And it matches up really well with the very bright Serfas TSL-350 headlight, reviewed here.
Buy this Serfas tail light if you don’t like using tools, you want to be easily seen from behind, and you don’t want to spend a huge amount of money.
In many ways, the Serfas Thunderbolt Bike Taillight is a perfect tail light for the Average Cyclist!
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