Anyone who does a lot of street commuting on an electric bicycle knows what a problem cars can be. Whether it is due to aggressive drivers or just plain inattentiveness, cars can be a serious concern for ebikers. Drivers are often scanning for other cars and simply fail to notice an ebike, even when it is keeping pace with them. It’s times like those that a loud ebike horn can stop a car from pulling out in front of you or accidentally merging onto you.
For years I’ve searched for a good quality, reasonably priced horn that could get the job done. There are some nice horns out there for bicycles but most are either prohibitively expensive, require their own annoying secondary batteries (and secondary chargers), or both. I love the AirZound horn for its decibels but hate the fact that I have to keep pumping its tank full of air. For too long I’ve been coming up empty on my search for the perfect electric bicycle horn.
But thankfully my search has ended!
Finally I’ve landed on the solution: electric motorcycle horns! They can run directly from your ebike battery which means less wiring and no second chargers. Your horn is always ready (as long as your battery isn’t dead, of course). Plus they take very little energy and are rarely used so you won’t notice any measurable drop in range either. What was once a scooter or motorcycle horn makes a perfect electric bicycle horn!
An ebike horn on a budget
These horns make great ebike horns because they weigh almost nothing, are easy to mount and best of all: they’re dirt cheap. The 48V version horn I use costs only $3 and that includes free shipping! It takes a few weeks to arrive, but you can’t beat the price. I mounted mine right on the front of my fork, but you could put it just about anywhere and mount it with a single bolt or zip tie.
[Update: Perhaps this article caused a rush on the horns, because the vendor immediately sold out. Don’t worry though, there are some similar (perhaps identical) horns from other vendors here, here and here. Hopefully their stock lasts a little longer.]
This 48V horn is perfect for anyone using a 48V battery on their ebike. I’ve tested it up to 59V and it has worked great, so it might work on even higher voltage if you want to give it a shot. At $3 it would be a pretty cheap gamble. The lowest I’ve tested it is at 40V. A 36V battery is actually 42V hot off the charger, so it would work on a 36V battery initially at least, but I haven’t tested how well it works on a nearly empty 36V battery. Fortunately there is a 36V version available, which is a bit more expensive, but still quite reasonable. If you have a 24V battery, you could run the 12V version horn, but you’d need a DC-DC converter such as this one.
If you’re worried about shopping on AliExpress and buying from China, don’t be. I felt a little unsure about it in the beginning, but I’ve bought more than I care to admit on AliExpress and had great experiences. When you buy a product they hold your money for between 30-60 days (depending on the product) and only pass it on to the vendor when you indicate that you received your product and everything checks out. On a few rare occasions I either didn’t receive my item or it arrived broken and AliExpress gave me my money back immediately. It’s also the best place to get most ebike parts, with prices a mere fraction of local suppliers. The main problem is the slow shipping. But when the price is that good, it’s hard to complain! I actually bought a similar 48V motorcycle horn on Amazon but it rusted out in less than a month. Turns out that this AliExpress ebike horn is cheaper and higher quality.
My experience with this ebike horn
My daily commute is about 12 miles (20 kilometers) on roads ranging from alleyways to 4 lane city highways and I see every manner of bad driving there is. One of the biggest problems I constantly see is a car underestimating my speed and accidentally cutting me off. Perhaps the driver sees a bicycle and assumes I’m going much slower than I am. A couple quick blasts on my powerful little ebike horn and they’ve instantly got eyes on me and their foot on the brake.
The other good use is for when I wind up in the blind spot of a car that wants to switch into my lane. I try to avoid that situation when possible, but if you ride enough miles then it happens eventually. When a driver starts moving over and suddenly hears a horn, they instantly pop back into their lane for fear of running into another car. I’ve seen a few surprised faces when they realize it was a bicycle that just tooted them back over the dotted line!
I generally find that two or three quick bursts on an ebike horn is a good ‘warning’ method. Counter-intuitively, a big long blast doesn’t seem to have the same wake-up effect as a few quick sharp honks in rapid succession. The 0ff-on-off-on effect has worked best for me.
To activate the electric bicycle horn, you’ll need some type of momentary contact button on your handlebars. Some throttles come with a green button that is usually perfect, if you aren’t already using it for something else. I picked up this multi-switch for less than $3. I use the green button for the horn, and the other buttons to activate my main head and tail light and my running lights. Wiring it is simple. Just run a wire from the positive output of your battery to one terminal of your switch. Then wire the second terminal of your switch to one terminal of the ebike horn. Wire the second terminal of the ebike horn to your battery’s negative terminal and you’re done!
Lastly, I’ve found that timing is everything. You have to be careful with this horn and only use it when appropriate. For example, when I’m up on the sidewalk and navigating between pedestrians I will only use my bell, NOT this horn. It’s simply too loud for that and can scare people, sometimes making them jump exactly to the spot you were aiming for. In my experience, people are more ‘trained’ to recognize the sound of a bicycle bell and respond more quickly and predictably to that sound. So for me it is bell on the sidewalk, horn on the road.
All in all I couldn’t be happier with this horn. The only way it could be easier would be if it came with a button already wired up, but then it’d be almost too easy and wouldn’t allow for customization. I highly recommend adding an ebike horn for any electric bicycle that rides on the road. This $3 purchase just might save you and your ride from a very bad day.