A helmet that speaks up when a car is closing in from behind sounds like an easy yes. The catch with Monarc’s Smart Helmet is the second purchase you need before that feature does anything.
Monarc lists the helmet at $229, and its store page says it ships within one week (checked October 12, 2026). The rear-vehicle alerts come from a separate accessory, the Ebike Rear-Vehicle Alert System, at $89. Its page says orders ship the week of November 9. Prices as of October 2026.
What the helmet does on its own
Without the radar, you still get a fairly full helmet. Monarc lists these features:
- Bluetooth speakers for music
- Phone navigation read out loud as turn-by-turn prompts
- Hands-free calls through a built-in speaker and microphone
- Front and rear safety lights that switch on when an ambient-light sensor sees dusk coming
- Turn signal and brake light integration
Fit is a dial adjustment, and Monarc calls the size “one size fits most.” If your head sits at either end of the range, that phrase is worth a second look before you order.
How the rear alerts work
The radar bolts to the back of a Monarc e-bike. Approaching vehicles appear on the bike’s display as green, yellow or red markers, depending on how close they are. You link it through the display or the Monarc app.
The helmet adds a spoken layer. Monarc’s help guide says the helmet sounds an audio warning when something approaches from behind. Electric Bike Report’s Weekly Recharge podcast put numbers on the radar: it follows as many as five vehicles at a time and reaches out to 460 feet. Those are the podcast’s figures. I didn’t see them on Monarc’s product page.
The free-helmet deals
If you haven’t bought a Monarc yet, the helmet may cost you nothing. Back in late August, 9to5Toys reported the helmet bundled free with the Marker at $1,999 and the Tracer at $1,899. That promotion was set to run through Labor Day. The podcast said the helmet was still coming free with a bike when it was recorded, but I can’t tell you whether that’s true today. Check the cart before you pay for a helmet on its own.
My read
I like the idea of a helmet that tells you about traffic. Staring at a display or a mirror while a truck passes at close range isn’t something I want to do, and an audio cue is the right way to deliver the warning. Dedicated radar taillights already do a version of this, and our roundup of rear and radar bike lights covers that group. Monarc’s twist is tying the warning to a helmet speaker and the bike display together.
Here’s what gives me pause. The radar isn’t shipping until the week of November 9, so a helmet bought today can’t give rear alerts for at least several weeks. Reviews on the radar page show the picture is still settling, too. Several recent buyers say it installed and works. One reviewer wished it sent audio to the helmet, which suggests that part may not be working for everyone. Another says the display colors wash out in bright sun.
That is a lot of unknowns for $318 combined. And the radar is built for Monarc bikes. Nothing in the material I reviewed says it works with another brand’s e-bike, so I wouldn’t count on it.
What I’d do:
- Own a Monarc, or about to buy one: Take the free helmet if the promotion is still running. Hold off on paying $229 until you’ve seen the helmet audio alert confirmed working.
- Ride another brand: Skip this. A radar taillight is a safer buy until Monarc says the system works off its own bikes.
- Care mostly about the helmet itself: Safety fit comes first. Our guide to wearing a helmet with a ponytail covers the strap and dial basics that apply to any helmet. For a different take on helmet design, POC’s aero helmet goes the opposite way, with no electronics.
Helmet rules are also moving in some states. If you ride an e-bike in Ohio, see what the proposed e-bike helmet bill would require, since a smart helmet still has to be a legal helmet where you ride.
Still unknown
- Whether the radar’s audio warnings reach the helmet reliably on day one
- Whether the free-helmet offer is still active
- Whether Monarc will sell the radar for non-Monarc e-bikes
- What safety standard the helmet meets. Monarc says its bikes are UL certified, but the product pages I checked name no government source for the helmet
Monarc’s support line, listed at (952) 234-8779 on weekdays, can answer the safety-standard and compatibility questions. I’d ask before buying.
Photo: Bicycle Helmet Protection Technologies by Brandenads, Public domain, via Wikimedia Commons. Cropped.
