Monkeylectric M133 LED Bike Light: First Impression

Back in July, the cool folks at Monkeylectric sent us a few of their M132 LED bike lights to try out. Moe wrote up an article about it then.

I got an M132 in the mail in August and slapped it onto my Xtracycle. After one hard rainstorm, I had a “freak failure” when one of the soldered switch legs corroded, causing a loss of contact. Granted, this was an unusual occurence, so I contacted Dan Goldwater, founder of Monkeylectric, to get his insight into things. Dan was quick to offer me the opportunity to test the revised M133 model and a prototype waterproof battery-holder cover. I must add that I sent the failed unit back to Dan and he got it to work again by lightly brushing the corrosion with a toothbrush, so there was no “catastrophic, unrecoverable failure” here.

What’s different about the M133? Well, it has beefier switches that are reportedly much more water-resistant than the older M132:

It has a revised battery-holder with extra “lips” to help retain the batteries at higher wheel RPMs:
retainer lips

Also, a couple extra programmable patterns were incorporated into the memory of this device. Let me tell you this: the colors and patterns in this device are mesmerizing — I blew through a set of batteries just playing with this amazing light before I ever mounted it on my bike!

The prototype battery-holder cover is made of rubber and it is designed to seal most of the moisture away from the batteries and their contacts. Dan estimates them at around 90% waterproof, and I’d agree…I’ve been through a few medium-intensity rainstorms with the lights now and I haven’t seen any evidence of water or corrosion in the battery-holder. Dan also mentions that they’re working on incorporating a snap-on cover that mounts partially underneath the battery-holder during assembly and this new setup should be almost completely waterproof.

Mounting these lights is a breeze. Simply select an area on your wheel and ziptie the device in place with the included ties and rubber vibration-isolating pads. The whole process takes about two minutes.

Let's roll

The M133 has nine user-selectable patterns and sixteen colors to choose from. The user can select 1-4 patterns and 1-4 colors at a time or the device can be set to randomly cycle through all 16 colors and 9 patterns. There’s a lot to play with here. In addition, there are three separate “speed” menus; they allow the selection of the speed of pattern-changing, color-changing and overall “mood” (simple or complex patterns). Finally, there are two intensity settings: regular and extreme. In regular mode, a set of batteries should last 15-30 hours. In “extreme” mode (which is quite eye-searing), the batteries can be expected to last 4-6 hours. The regular or high-efficiency mode is plenty bright, though — and the lights will spread a bright patch 3-5 feet to each side of the wheel while it is in motion.

Here’s a couple still shots of the lights in action. First disclaimer: the colors are much more vibrant in real life and the patterns even more complex.

pattern 1

pattern 2

For even better photos, please visit our friend Derek Pearson at The guy is a professional photographer (rather than a point-n-shoot hack like me), and he was able to catch nearly the full intensity of these wonderful devices.

And, here is a Youtube video that gives you an idea of what these lights look like in action. I was dismayed to realize that the video didn’t accurately reflect what these lights are capable of, and Dan explained to me that, “the reason is that most consumer video cameras shoot at 30 frames per second, but your eye is closer to 10 frames per second. So your eye sees a tracer that is 3 times longer.” Basically, in real life the lights trigger a tracer effect that fills in any gaps in the pattern…it’s quite striking!

For reference, I have two lights mounted. They are both set to display all 16 colors and all 9 patterns randomly at medium-high speed.

The lights are packaged with an excellent instruction/programming and installation guide and all the necessary hardware needed to mount the lights. And, customer service from Monkeylectric is top-notch…they quickly answered any questions I had and handled my device failure with aplomb.

Do these lights work to help keep a bicyclist safer at night? Well, I’ve had a lot of amazing reactions…pedestrians hollering at me, motorists pulling up alongside me to ask about the lights (motorists, I appreciate the curiousity, but please don’t roll up next to me — it startles the hell out of me!). Visibility with these lights is quite astonishing, and the light is visible from the front and back as well as the sides.

We’ll see how these devices hold up under Florida’s grueling conditions…but for now, I’m hooked. These lights are fun, colorful and really make a bicyclist stand out in the dark — that’s a win-win in my book!


  1. Moe

    Cool video! We did get to talk to the people from Monkeylectric at interbike. I will do a post soon with pictures AND video.

  2. Franklin

    Visibilty looks good on those, and I like those lights, may have to get some. What would be a comparison b/t these and down low glow?

  3. Ghost Rider

    Down Low Glow makes a static “pool” of light below and to the sides of the bike, while the lightpool generated by the M133 is continually changing and flashing.

    Both would be wholly adequate for a huge increase in nighttime safety, especially from the sides, where current bike lighting is lacking.

  4. peteathome

    I wonder if these could cause accidents due to other road users being distracted by the light show

  5. Ghost Rider

    That’s an interesting question, and was something I talked about with a Sheriff’s deputy who I work with — he told me about all the crashes that happen when motorists get mesmerized by the flashing cop car lights at the side of the road…a LOT of police cruisers and officers have been plowed into.

    Who knows if the same might apply to these lights? I know that they’re not overwhelmingly visible from the front or back…just bright enough for motorists to see that something is interesting up ahead. Let’s just say “gosh, I hope not!”

  6. Mike Bull

    Indoor LED Gardening Tips

  7. Raiyn

    Any further updates?

  8. Ghost Rider

    Raiyn, both units in our fleet are going strong…the contacts get a little bit of white corrosion and the battery pack’s springs are a little rusty, but the lights function fine. That rubber battery cover seems to do what it is supposed to.

Leave a Comment

Your email address will not be published. Required fields are marked *