The Sentinel 40 from NiteRider is one of the best taillights you can use for riding on the street, day or night. With 7 modes, including lasers that create a “virtual bike lane”, you have a much better chance of being noticed by motorists, and from a greater distance, which is key to not becoming a statistic.
Yes, lasers. The Sentinel 40 is a Class 2 laser device, and they actually had to get FDA approval for it. If you press the right hand button on the top of the light, you can cycle through the three laser modes – slow flash, fast flash, and constant. This projects a pair of bright red “virtual bike line” beams on either side of you. NiteRider calls them Laser Lanes, and it is not a gimmick – this has gotten positive feedback from both cyclists and motorists. Of course, there’s more to it than just lasers, but anyone reading this article probably wanted to know about that first.
In addition to the lasers, the 73 gram Sentinel 40 has two steady and two flashing modes to make sure you’re seen. I like the fact that the flashing patterns are variable, making them stand out more than a simple on/off flash. And they are bright, thanks to the 2 watt LED that puts out 40 lumens on high. Charge the 1000 mAh Li-Po battery for 4 hours, and you’ll get 18 hours on the first flash option, 7 on the 2nd. Switch to the steady mode, and run times are 4.5 hours on high, and 36 on low. That’s some long run times for commuters, and you can charge it easily with the included micro USB cable, which has become the standard for nearly every USB device out there.
NiteRider ships the Sentinel 40 with a very adjustable clamp to fit just about any seatpost, or you can use the built-in clip to attach it to a bag. For maximum effectiveness, I would make sure to mount to your seatpost, or buy the optional ($9.99) rack mount, for the most solid attachment. If you mount it to a backpack, under-seat bag, or trunk bag, I think it may bounce around too much, so the lasers will be less effective. We tried each way just to be sure. On my rear rack, you can see some keystoning in the beams (below). Not sure if I can bend something to straighten them out.
In use on my fat bike, the Sentinel 40 made it easy for me to be seen from a distance. As motorists get closer, the Laser Lanes are more visible, which can serve as a reminder to allow for some extra room. When you combine that with the flashing red LED, your odds of being seen improve quite a bit. And the red is so bright, I run it during the day as well. In our tests, it really does grab attention. NiteRider lists the MSRP for the Sentinel 40 at $49.99, which seems like a bargain for the extra measure of safety. They also bundle it with their Lumina OLED 800 headlight, which we reviewed last month. We found the bundle on Amazon for $149.99, which is $50 off the MSRP from NiteRider. That’s a sweet deal on a great set of lights.