wispfox

Posted by Tim McCormack

https://www.brainonfire.net/blog/2025/12/13/from-bontrager-to-fenix/

After my fourth Bontrager bike headlight died too soon, I've made the switch to Fenix. While it's too early to have personal experience with the durability of Fenix, I'm really happy with the switch, and I wish I had done it sooner—it's clear that Fenix stands behind their products in a way that Bontrager/Trek does not.

Bontrager problems

My first Bontrager headlight was a gift, so I don't have a record of what exactly it was, but I think it was one of the white 800 lumen Ion models. Overall it was great—waterproof, solid construction, high output (about as bright as a car headlight), and easy to use. USB rechargeable and decent battery life. Several modes.

Frankly, this is table-stakes for a bike light for me these days. But there were two things missing: Repairability, and a warranty of more than a year or two. Foreshadowing, obviously, but at the time I couldn't find anything better in that regard.

I don't know what happened to it, but I do know that I then bought the 1000 lumen "Ion Elite R" for $100 in Nov '20. This one died when the button rubber decayed and fell off, exposing the guts to the elements.

And then another "Ion Elite R" for $110 less than a year later, Sep '21. On that one, the USB port broke—it snapped right off an fell into the housing. On closer inspection, it turns out that the USB port was only held onto the circuit board by solder! There was no mechanical backstop other than the wiring itself, which is a ridiculous design for something with so many plug/unplug cycles.

Trek sent me a replacement "Ion Pro RT". (Fun side quest: REI incorrectly refused to honor the warranty and had me call Trek instead. Trek at least made it right, rather than making me schlep all the way back out to REI.) It died two years later, in Nov '24.

I got another one, like a fool, because I was used to buying Bontrager and didn't know that the market had opened up a bit. This one survived being run over by a car (they do have solid construction!) with nothing but scratches, but eventually started cutting out on the highest brightness and finally, like clockwork, died in Nov '25. Just out of warranty.

Upon dissection, this one turned out to have a bad battery protection board. The battery itself was still good, but the tiny board sitting on top of it wasn't letting power through. (Unfortunately, in the process of debugging this, I shorted something out and the magic smoke came out somewhere in the main board. But I wasn't going to solder a new battery in. I'm terrible at soldering, and batteries are tricky.)

I was fed up.

Fenix to the rescue

I asked around on Mastodon: Is there some other product I should be looking at? And multiple people recommended Fenix, which I had never heard of. Apparently they're broadly a flashlights (and generally portable lighting) brand.

Their BC26R bike headlight had two critical features that Bontrager was sorely lacking:

• 5 year warranty (plus limited lifetime warranty)
• Replaceable lithium battery (a chonky 21700, but can also take a 18650 if a shim is used)

This tells me that Fenix means for their products to stand up to actual use. (Note that not all of their lights have a 5 year warranty, or other features I describe here. But they do offer it on this one.)

Besides the above, I also like these aspects:

• The button is metal, so it won't decay from UV and surface exposure to grease or other chemicals. (I'm sure there's a rubber or silicone membrane deeper in, of course.)
• The button is very easy to press. This could be a problem for some use-cases, but I often struggled to turn on the Bontrager while wearing thick gloves.
• The USB port isn't overly deep, so I don't struggle to plug it in.
• The quick release lever on the mount is fat and nearly flush with the back end of the light, so I can remove the light even with thick gloves.
• The light came with a spare o-ring for the battery cover seal. This is really thoughtful.
• If the battery level drops too far, the light automatically switches to low intensity.
• There's no Bluetooth or other wireless connectivity. I regard this as a plus in safety equipment.

As a bonus, I paid $90 and that included a tail light.

It's not perfect, of course! I'd love to see Fenix make some improvements:

• The beam is circular, which is... not great for traffic. I don't want to blind oncoming traffic, and having a sharp cutoff on the top edge would help greatly. Some manufacturers have a lens that directs the upper end of the beam downward. I'd like a sharp cutoff on the top, a wide beam for seeing what's happening ahead to the sides on a turn, and then a narrow beam for the bit of road right in front of me so I can spot potholes. (And then nothing shining on my front wheel.)
• I have to tilt the beam up and down depending on traffic conditions (especially on shared-use bike/pedestrian paths) but the mount only wants to turn one direction. I haven't really figured out how that works. Maybe the texture of the mounting shim? But it would be nice to have more ability to adjust the pitch. (Most headlight mounts allow some sliding on the handlebar.)
• You have to double-press to switch to flashing, but when you change back to solid mode, you're now at a different intensity level than you started with—because the first press changed that level. This is a minor issue but probably really easy to fix!
• The charge indicator light (embedded in the button) turns green or red (and steady or flashing) depending on charge level. This is fine, but the button itself is a copper color, which means that out of the corner of my eye it always looks red. This is a really minor issue, but I'm hoping that a silver finish would be an easy change to make.
• I would appreciate having a flicker-flash mode. The Bontragers had a mode that was relatively low intensity but that did a quick flicker sequence about once a second—not fully on and off, and not continuously flickering (both of which can be overly distracting) but just an intermittent rapid dimming and brightening cycle. I overall don't trust slow flashing modes because drivers might only glance at me and I don't want the light to be super dim or dark during that glance.

https://www.brainonfire.net/blog/2025/12/13/from-bontrager-to-fenix/