Light Up The Night With The Serfas TSL-550 Headlight

Serfas TSL-550

Yogi Berra once said “You‘ve got to be careful if you don‘t know where you‘re going, because you might not get there.”  With the Serfas TSL-550 headlight, you still may not get there, but you’ll definitely see everything on the way. Upon receiving this headlight, I was initially a bit disappointed to find that it was only a 550 lumen model rather than one of their higher output headlights. That is, until I pressed the translucent power button of immense glory on top. The Serfas True 550 headlight easily out-performs any light I‘ve ever used.

The Serfas TSL-550 headlight is styled like a 70‘s hot rod, with its sweet ram air induction, aluminum light bezel and a model insignia on its nylon side. Peak output is 550 lumens with 4 light stages and a flashing mode.  A reasonable 195 grams for the light and 235g or 0.51lbs with the bracket is barely noticed, even while on the helmet.  Charging this light is simplified by its micro usb port. Serfas also built in smart charging technology to help prolong battery life and prevent overcharging. This protection feature helps to ensure your TSL-550 lasts its full 50,000+ hours. Should the light get too hot from inadequate airflow due to mud, dirt, or having to hike your bike up a hill, the light will even default into standard mode until the temperature comes back down. Run times vary according to the power setting, and the Serfas TSL-550 run time is 2 hours on overdrive and as much as 9 hours and 30 minutes on the low setting. The power button lights up blue unless the power threshold falls below 20% charge, causing the light power button to flash red.

Serfas TSL-550 helmet mount

After reading the included manual, I had a lot of fun using the Serfas TSL-550, doing my testing based on distance and speed. Its low to medium settings are great for lighting up the road when cruising along at a casual pace, while the high setting gives you confidence on those epic descents. The best run time I experienced was 3 hours on the overdrive setting with a full charge. Putting the light into flashing mode isn‘t easily figured out unless you read the included manual. To enter or exit flashing mode, users must hold the power button for 2 seconds to cycle back to their desired mode. I‘m not real fond of this feature and hope that they change this in the future. The hook and loop strap that attaches the helmet mount does a great job of holding the light as long as you really pull tight to fasten it. After doing this it did not move around at all on my helmet.  Upon attaching the handlebar mount to my bike I found that the 31.8mm handlebars were a bit wide near the stem for the light and removed the upper rubber strap inside the handlebar mount.  This enabled the mount to fasten easier with less fuss. Given a choice between using the handlebar mount or the helmet mount for light placement, I prefer the helmet mount.

A good quality light makes worlds of difference when riding, and the Serfas TSL-550 fits the bill. With its MSRP of $140, this guy puts out more light than I could ever want. It allows me to see and be seen. No doubt you really get what you pay for. For riders that require a bit more or less light output, Serfas offers lights to accommodate both, with prices to match.  Check out for more details and their full product selection.

– Ryan

Disclosure of Material Connection: I received the Serfas TSL-550 for free from Serfas, in consideration for review publication


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Dave Reo

Worth looking into for sure. Shorter days are on thier way.


I think 550 lumen would be great for a headlight, but on the handlebars I need at least 1000, especially when out riding trails etc. I agree with you on the flashing side of things, I don’t understand why this is offered on so many lights – it just isn’t practical and can be pretty dangerous when you’re going quick!

What was it that made you prefer the helmet mount to the handlebars?


I liked the helmet mount due to being able to point the light where I’m looking. It’s a bit heavy until you get used to it. I only use the helmet mount when I’m mountain biking though. When i’m on the road I put it on the handlebars.


I typically use two lights but last night I just used the helmet mount. I could see plenty for what it’s worth while mountain biking.

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