Hornit dB140 Electronic Bike Horn

The Hornit dB140 V3 is an electronic bike horn for riders who share the road with cars.

Hornit rates it at up to 140 decibels in its road mode, designed to get a driver's attention where a bell often goes unheard.

A second, lower-pitched 121dB mode is there for shared paths. A wired thumb trigger lets you sound it without taking your hand off the brake.

Two sounds for two situations

• Road mode (140dB): a piercing alert for traffic, for when a driver hasn't seen you and you need them to, right now.
• Horn mode (121dB): a lower-pitched horn sound for shared paths, still clearly louder than a bell.

Use road mode for cars, not people. At close range, 140dB will startle pedestrians and other riders, so switch to horn mode on paths and save the loud setting for traffic.

Sound it without letting go of the brakes

The horn mounts on your handlebar and connects to a small thumb trigger on a cable, which you position next to your grip or brake lever.

When you need it most, you're usually braking at the same time. The remote trigger means you don't have to choose.

Mounting

The V3 uses a new Garmin-style quarter-turn mount: it holds solidly on the bar and twists on and off in a second.

The mount also takes other Garmin-compatible devices, such as a bike computer. Two mounts are included:

• 22 to 26mm mount with four spacers, for the narrower section of most handlebars, near the grips.
• 31.8mm mount for oversized road and mountain bike bars.

Fit one mount to each of two bikes and move the horn between them. The mounts need round handlebars: they don't fit flat-profile aero bars.

Batteries and weather

It runs on two AAA batteries, included.

Hornit quotes up to 12 months of battery life based on about six one-second blasts a day.

It's rated IP44, which means it handles rain and road spray, but it isn't waterproof, so don't submerge it or point a hose at it.

Frequently asked questions

Is an electronic horn legal on a bike in Australia?

Yes. Australian road rules require a bicycle to have a working bell, horn or similar warning device. An electronic horn like the dB140 meets that requirement.

How loud is the Hornit dB140?

Hornit rates it at up to 140dB in road mode and 121dB in horn mode.

Is the dB140 the loudest bike horn?

Hornit markets it as the loudest bike horn available. What we can confirm is Hornit's rating of 140dB in road mode, well above a traditional bell.

Is the trigger wireless?

No. It's a wired thumb trigger, so there's no second battery to charge or pair.

Will it fit my handlebars?

It comes with mounts for 22 to 26mm and 31.8mm round handlebars. It won't fit flat aero bars.

Is it waterproof?

It's rated IP44: fine in rain and spray, but not waterproof or submersible.

What batteries does it use?

Two AAA batteries, included. Hornit quotes up to 12 months of normal use.

Specifications

• Model: dB140 V3, black.
• Sound: 140dB road mode, 121dB horn mode.
• Trigger: wired thumb trigger, 355mm long.
• Mounts: Garmin-style, 22 to 26mm (with 4 spacers) and 31.8mm, round bars only.
• Weather rating: IP44. Power: 2 x AAA (included), up to 12 months (Hornit figure).
• Weight: 102g with larger mount and batteries (horn 48g, trigger 10g).
• Horn dimensions: 98 x 48 x 42mm.