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  • Portland Design Works - Gravity 80 USB Auto Tail Light - One Color
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  • Portland Design Works - Gravity 80 USB Auto Tail Light - One Color

Portland Design Works Gravity 80 USB Auto Tail Light


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    • One Color, One Size

    1 Review


    Brake safer.

    If your commute takes you winding through the cities, or your group rides can get a bit crowded and chaotic when it comes to stop lights, throw the Portland Design Works Gravity 80 USB Auto Tail Light on your ride. This handy light doesn't just offer you the reassurance of a flashing or steady tail light, but it also adds a built in accelerometer to the mix. The accelerometer on the Gravity 80 registers when you're accelerating or decelerating, illuminating a second LED that shines at a brighter 100-lumens when you brake, so motorists and fellow cyclists get an alert to let them know what's going on ahead. It has two modes, flashing 80-lumen, or solid 20-lumen, depending on your riding needs, both work with the brake light, and it can be mounted either vertically, or horizontally to your seatpost or seatstay.

    When you're getting ready to hit the road, Portland Design Works recommends calibrating the light first — don't worry, it's not a daunting task. Simply install your light on its mount before powering it on, and hold it still for one-second before hitting that power button, then you're good to go. The light will be ready to roll for up to 12-hours on solid, or 30-hours on flash, and can be recharged at your buddy's house or the office using a compact Micro USB charging cord.

    • A smart bike light for safer braking and riding
    • Built in accelerometer illuminates light when braking
    • Brake light provides a full 100-lumen glow
    • Battery lasts a full 12 hours on steady, 30 on flash
    • USB rechargeable battery can charge at the office or home
    • Flexible mounting can run vertical or horizontally
    • Pick your favorite mounting spot on seatstay or seatpost
    • Weatherproof construction for commuting in every season
    • Item #PDW001L

    Tech Specs

    Power Source
    li-polymer battery
    Batteries Included
    solid, flash
    [solid] 20, [flash] 80, [braking] 100
    Burn Time
    [solid] 12 hrs, [flash] 30 hrs
    seatpost, seatstay
    light, seatstay bracket, seatpost bracket, micro USB charging cord
    Claimed Weight
    Recommended Use
    commuting, road cycling
    Manufacturer Warranty

    Tech Specs

    • Reviews
    • Q & A

    What do you think about this product?

    Have questions about this product?

    Bright and reliable

    • Familiarity: I've put it through the wringer

    I quite like this light. It is very bright in its blinking mode (80 lumens) which is a bit more than the nice Knog (75 lumen) rear light I also own. It recharges quickly, much more so than the Knog does. It attaches easily and reliably with a simple, beefy rubbery strap. It has a great feature through the use of an accelerometer - when you slow, it changes to a solid unblinking light, giving a 100-lumen car-like braking light effect. Pretty neat.