Serfas Thunderbolt Bike Lights—Bringing Safety and Smiles into the Darkness

Serfas Thunderbolt Bike Lights—Bringing Safety and Smiles into the Darkness.

On this eFlow electric bike there is no seat post to mount lights on. The Thunderbolts didn’t care.

You may already be asking yourself what kind of nut gets all smiley and happy about a bike light. If you are, then hang in there for the details. If you understand where I’m coming from, then you will be even more pleased to learn more about these lights from Serfas. Thunderbolts come in many colors and you have your choice of a front or rear light. The pair I just got add even more to the table.

It was about a year and a half ago when I got my first Thunderbolts. The added safety and convenience they offered did make me happy (smiley too). They mounted easily on an E-bike where other lights wouldn’t. Way bright, quick to recharge and water-resistant, These lights work for me in ways I hadn’t experienced before. We have many bike lights and I find these to be amongst the best of them.


The new Thunderbolt lights can be seen from so many angles. Very nice.

These new ones I just got have a translucent body that allow the light to be seen from more angles. It only makes sense and tells me the designers at Serfas have their thinking caps on tight. The solid build and great features of the Thunderbolts are still there, with a lot of good reasons to strap a pair (or more ) on your bike.

The first thing that got me with these is their mounting versatility. That has been a big draw-back on many of the lights we have. Most are designed to go on a seat post, with different sized mounts included. On several of our bikes (and ones I test) the light can’t be seen when on the post because of racks or other items behind them. And when the seat post is set real low there is no room for a light mounting. These solve that problem easily. They can strap on most anywhere.


This front Thunderbolt is on the steerer tube of my wife’s new IZIP E3 Path+. It really lights up the night.

The front ones (white lens) have longer straps that allow a wider mounting range. You can put them on the handlebars, front fork or even on the steerer tube. This last choice has worked our great on my wife’s new E-bike. It is out of the way and in a great spot for everyone around her to see it. You may know that we both use flashing lights front and rear in the daytime for extra safety. The steerer tube mounting is perfect for that. And at night it gives a wide un-focused beam that is acceptable.

By recharging through a USB port, you never need to replace any batteries. This is a plus from not only a cost standpoint, but one of sustainability. The Thunderbolts have a charge indicator light to let you know when they are topped off and they use a standard cord (of course one is included with each light). They take 3-6 hours for each charge depending on a couple factors.

They stay lit for close to 10 hours on the lowest flashing setting (what we normally use as they are just so bright). In the highest setting you get just 1 ½ hours of light. That high setting is mostly used by us in the front mounted headlight at night. As far using them as your only headlight, if you are a fast rider you will need a quality focused headlight to compliment the Thunderbolt (Serfas offers those too). If you are just a mellow speed cruiser, the Thunderbolt will do fine as an only headlight.

When it comes to taillights these are great on the low flashing mode. This is where these lights keep me smiling. I just can’t say enough about the ease they have in moving them from bike-to-bike. The brightness is exceptional and they have worked flawlessly. I too like the way the switch works (see the next paragraph).


Very bright, rock solid and easy to mount, these lights get me kind of giddy.

There are four power levels the Thunderbolt can operate at. Two levels of steady on and 2 of flashing on. They are so bright they recommend not looking directly into the light. In the highest setting they claim it can be seen from a mile away. The power switch is simple to use as you toggle from off, to full bright, to low bright, to full bright flashing, to low bright flashing and then off again. The kicker here is no matter what mode you are in, if you hold the button for a little bit it goes right to off. No more toggling to find the off position, genius at work.

All of my Thunderbolt lights have worked perfect with each use. I did find one little thing that allowed me to experience the speed and quality of the Serfas service and warrantee department though. I will point this out so you don’t have to do the same. I don’t know that they will replace every lost strap, but they did for me. This was just one more factor that puts Serfas on my best bike parts company list.


Here you can see the smaller holed end is designed to stay on the light’s body so you don’t loose the straps.

If you look at this photo you will see how one end of the strap is designed to stay on the light. The other end is the one you release for the install and removal. If you don’t keep the small holed end on the light you might lose the strap like we did. Try to avoid that.

Thunderbolt, a cool name and great light, Turbo Bob.

“One of the most important days of my life was when I learned to ride a bicycle.”—Michael Palin.

Serfas on the web and Facebook

Here is the video I did a ways back on Serfas Bike accessories.


About Turbo Bob's Bicycle Blog

E-bike Enthusiast Vintage Bike Enthusiast
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2 Responses to Serfas Thunderbolt Bike Lights—Bringing Safety and Smiles into the Darkness

  1. SombraCycle says:

    We all love cool accessories for our bike. They just make us love our ride even more. Bicycle safety accessories, though, tend to get a bad rep for being kinda boring but obviously that is not necessarily true!


  2. Thanks for the review–probably pushed me over the edge to ownership.

    I saw a lot of Thunderbolts–high setting during daylight–on the most recent Midwest Tandem Rally. (I also saw a lot of Click-Stands keeping tandems upright while parked.) I picked up one of the lights at Cyclextreme in Columbia, Missouri, and I’m happy to report it attaches quite nicely to the back of an Arkel TailRider.

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