Portland Design Works Gravity+ USB Tail-Light


Portland Design Works Gravity+ USB Tail-Light

  • Available prices $49.00
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Free in-store pickup

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Show Description

Does your bike have a brake light? It could. The Gravity+ from Portland Design Works has an internal accelerometer that triggers a bright red light as you brake or swerve, instantly letting those around you know to pay attention. Whether you're riding in a pack, on a busy seawall or in traffic, an easy way to let those around you know when you're slowing down or changing direction is a game changer. Besides the accelerometer-driven features, it has both a steady and a flashing red light mode. Easy USB charging means you can top up your battery nearly anywhere you go.

  • 2 Modes: steady 20 lumens (12 hours) and flashing 80 lumens (30 hours).
  • Brake light shines 100 attention-getting lumens of red light.
  • To calibrate the accelerometer, always install the Gravity+ on your bike before powering it on. Hold the power button down for 1 second to turn the light on or off. Then, keep your bike still for 1 second after pressing the power button to complete the calibration.
  • Weatherproof housing shrugs off any weather you're willing to ride in.
  • Lumens and runtimes certified by Labsphere Illumia Light Measurement system to FL1 standard.
  • Includes a rotating tool-free seatpost mount that makes switching bikes easy, and a bolt on seatstay bracket.
  • Includes a micro-USB charging cable.

Tech specs

Show Tech specs
Weight 54g
Included mounts
  • Seat post mount
  • Seat stay mount

Most Canadian municipalities require a white front light and a red rear light.

Lighting levels

The number of lighting levels/modes the light has (i.e., low, med, high, flash).

2 modes
Light source LED
Burn time - flash 30 h
Burn Time - steady 12 h
Max light output

The total quantity of light emitted in every direction from a source of light; measured in lumens.

100 lumens
Charge time

The amount of time it takes to fully charge the battery. Applies to lithium and NiMH type batteries. Does not apply to rechargeable or non-rechargeable AA or AAA batteries.

2.5 h
Power supply USB charger
Helmet attachment

Includes a bracket or mounting system that attaches to most bike helmets.

Emits red light Yes
Regulated output

On regulated lights brightness is consistent, and does not decrease gradually as the batteries are drained.

Batteries Rechargeable battery pack (non-removable)
Flash mode Yes
Made in Taiwan