Cardo Bk-1 DUO Review

by Brian Mullin on September 8, 2012

Cardo Systems are best known for their wireless Bluetooth communication systems for motorcycles, and they recently released the cardo BK-1, which is a communication and entertainment product specifically designed for bicyclists. The BK-1 offers communication between other BK-1 equipped cyclists, and it gives the user hands-free use of Bluetooth-enabled mobile phones, MP3 players, or GPS devices.

Cardo BK-1
The BK-1 is a multi-purpose system and is an intercom which allows two or three-way bike-to-bike conferences at a range of up to 500 m/1,640 feet, and it can be connected to any Bluetooth-enabled mobile phone, GPS and MP3 player. The latter functions as both a music player and phone interface. It connects or pairs to the devices on two different channels, which are designated “A” and “B”. The essential portions of the BK-1 are the headset (i.e., the brains) and a pair of speakers with a microphone.

The BK-1 is lightweight, waterproof and dustproof, and has a seven-hour battery life from its internal rechargeable Li- Polymer battery. It takes three hours to charge through its multi-functional USB, which also allows a hard wire MP3 player to be attached, and is an interface when new firmware updates are available. For audio, it uses two hovering speakers with flexible booms, and the right speaker has an Omnidirectional microphone. It has advanced hardware and software features, including Voice-control (VOX) for receiving or rejecting incoming mobile or intercom calls, Packet Loss Concealment (PCL) for compensating audio packet losses, Digital Signal Processing (DSP), Advanced Gain Control (AGC) that automatically adjusts the volume, and echo cancellation.

The Bk-1 can be purchased singularly for $274.95 or the DUO (as tested), which has two full BK-1 kits and retails for $479.95.

The DUO kit comes with two full BK-1 systems, a user manual in three languages (English, French, and Spanish) and a padded case. The systems are comprised of the headset, right and left speaker (right has the microphone), a stub out (if only using the right speaker/microphone), a cradle with an optional spoiler,  multiple Velcro pads (small, medium, large), USB wall charger, USB adapter cable, short and long attachment straps, MP3 cable and additional microphone sponge.

Measured Specs:

  • BK-1 – 41 grams
  • Cradle w/ short strap (i.e., the mount) – 11 grams
  • Speakers – 65 grams
  • Total BK-1 system weight – 117 grams


The BK-1 headset has five buttons that perform all of its functions, including turning it on and off, pairing to other devices, receiving and rejecting phone calls, selecting intercom channels, adjusting the volume, and enabling and disabling several features.

The main button for everything is the Mobile Phone button, which powers the unit on and off, pairs and connects to the mobile device, and answers rejects or ends phone calls. The volume buttons adjust the volume up or down (obviously), checks the battery level, mutes the sound, and enable/disable AGC and VOX functionality. The volume buttons also house the indicator LEDs, which is either flashing or solid colors, in red, blue and occasionally purple. The LEDs indicate a plethora of statuses and conditions, including battery levels, modes (active, standby and charging), powering up and down, and features enabled/disabled, and pairing setup. Also, specific tones will be heard from the speakers, depending on modal changes, whether it’s from power, intercom, and mobile devices. The Channel A and Channel B buttons connect you to an already paired BK-1 on the same channel and also facilitate pairing the intercom devices.


The first thing to decide is whether you want the BK-1 headset attached along the top or rear section of the helmet. I installed it in both areas, and found that the rear was less obtrusive, made routing the speaker wires easier, and allowed me to use a helmet mounted POV video camera. Regardless of the spot that is chosen, follow their detailed instructions (which sort of confused me) for installing the headset cradle, using either the short or long Velcro strap. After installing the cradle, figure out where the speakers will fit the best in the bottom rear of the helmet, and apply the appropriate sized Velcro stick-on loop pad (either the large or medium) to that spot, and wait 10 minutes. I am not sure if it matters if you wait 10 minutes since sticky pads of any sort don’t adhere to EPS foam very well (more on that later).

Attach the Velcro speaker booms to their counterparts inside the helmet, and route the wires outwards to the cradle, connect them together, and then snap the cable’s audio connector into the cradle’s socket.

Install a freshly charged headset into the cradle, by snagging its front end on the cradle’s hook, and then push its rear down until it snaps into place.


The BK-1 is a full-duplex intercom system, which means the devices can communicate with one another in both directions simultaneously, like a phone in contrast to a walkie-talkie, meaning you can listen, yak and interrupt one another at the same time. The BK-1 also facilitates hands-free Bluetooth-enabled mobile phones, MP3 players, or GPS device connections. Each unit has a channel A and B, so the intercom can connect on either channel after being paired with one another. For a three-way setup, one cyclist has to be the conference leader, and pair themselves on channel A to one user, and on channel B to the other. Unfortunately, when doing the three-way conference, you can’t receive phone calls through the BK-1.

So what makes using an intercom system special while biking? Although you can converse with one another when riding side by side, it’s not always the safest or the most practical method, whether that’s on the road or a trail. Using a system like the BK-1 allows you to converse with one another at reasonable volumes, and ride in single file, whether you are close or separated by some distance.

I found the BK-1 quite useful for simple conversations or to check on something with your compatriot while riding on singletrack, especially when it was windy or the trail caused background noise (rough). I never had to raise my voice or yell to be heard, as it can sometimes happen on a ride, which was nice when you are winded or panting, i.e., sucking the wind. The sound on the intercom was clear, loud, and distinct, and I could easily understand words and conversations. I enjoyed having the unit when I was riding with my kids, as it allowed easy communication with them during a ride, for more enjoyment and comfort. I would think it would be quite useful for training, either as a coach or training partner? It made BS sessions with a riding buddy very entertaining, and rides took on an entirely different aspect, adding to the quality and enlivenment of the experience.

The installation was pretty straight forward, and it was simple to pop the headset out of the cradle (and back in), for charging or storage. I found that taking the speaker or audio units off was problematic because the sticky Velcro pads would almost usually come off with them, so you would regularly need to apply new pads to the helmet, and although the kits contain quite a few of them, I would have liked a few more. It’s not an issue with their system; it’s just that EPS foam and stick-on pads always detach with time, and their adhering qualities with each other are poor.

The weight of the system, including the headset, mount and speakers come in at a respectable 117 grams. Although that isn’t light, the weight distribution of the speakers on the side and headset in the middle, kept the weight low and snug and centered to your head, making it feel that it isn’t there. Fitting the speaker by your ear was simple, and it gave you lots of fine tuning, and you could push them farther away from your ear or closer for better listening, and up out of the way when you needed to concentrate or weren’t using them for anything.

The BK-1 DUO which I tested already had the two units paired with each other on Channel A, but even if they weren’t paired, it’s a relatively simple process to connect them to each other. You hold either the Channel A or B button down on the first BK-1 for four seconds (blue or red LED flashes rapidly), and immediately do the same on the second unit, and then a solid light shows that they are paired. To start the intercom process between them, turn both unit’s on, and either shout into the microphone or tap the paired Channel (A or B), and communication will commence. If the line goes dormant or the intercom has been silent for over 30 seconds, another loud hello or tap of the appropriate button gets things going. On rare occasions, it seemed to get confused, and it would take a few tries to re-engage the communication system. If one person was on a phone call and the other initiates a connection, both of you get a busy signal, and things will start back up when their call is completed. There is a hierarchy of priorities for the audio sources, and the mobile phone audio is the highest, then the intercom and so forth, so an intercom can’t interrupt a call.

Although the lights on the buttons helped with doing the settings, they were difficult to see in bright light conditions, and since the headset was on top of your head, you either had to remove the helmet for viewing or have your partner confirm the patterns. The buttons were distinct, yet had a nice soft feel, and were easy to use even with gloves on, though I must admit I sometimes forgot, which was the A or B channel button?

I tested the communication range all over the place, and if you had an entirely clear line of sight you might get close to 300-400 yards, but if obstacles, especially dense trees were among riders, then the distance dropped to 100 yards, and sometimes it was poorer. Although foliage and trail obstacles dropped the distance down substantially, you could still hear one another, albeit it had a static background noise, as you get between radio stations, though at a lower frequency. All it meant was that you had to keep some closeness between one another and line of sight if possible (keep one another in view), which wasn’t difficult on most terrain unless you were hauling downhill, and during that situation, it wasn’t that big of a deal. Dense forested areas seemed to cause more issues than other terrain features.

To be honest, my favorite usage of the BK-1 was for the personal hands-free use of Bluetooth-enabled mobile phones, which in my case was my iPhone. I loved being able to stream music from my smartphone to the BK-1, and then pick up and answer calls without having to take the phone out of my pack. Another significant advantage of the system is that the speakers sit outside and away from my ears, and although I could hear the music just fine, I could still hear and interact with things going on around me, allowing me to pick up ambient sounds and spatial cues. If I needed additional hearing acuity, I could easily pop the speakers up out of the way from my ears, like wings, giving me complete attention to things. That was a significant advantage over ear buds, which significantly isolate you from your surroundings, though I’ll give them a slight upper hand in the acoustic department. Sound reproduction was fine with the BK-1 speakers, not audiophile standards by any means, but adequate for its background purpose, and I found it perfectly enjoyable for my music listening pleasure. I could also hear phone calls just fine, and my party inferred it worked well on their end. The unit has AGC, or Automatic Gain Control enabled (by default), which adjusts the volume to the ambient noise and riding speed, but I sometimes found it would freak out, and would occasionally change volume in mid song?

Like any Bluetooth setup between devices, it takes an initial pairing between BK-1 and the mobile device (smartphone). Hold the headset’s mobile button down for six seconds until it flashes red, and continue holding the button until the red and blue rapidly alternate, and search for the Cardo on the smartphone’s Bluetooth queue. When the pairing has completed, just turning the headset on and pushing the middle mobile phone button to get things rolling after a short period once you start your music. To answer an incoming call (you’ll hear your specific ringtone from the speaker), you tap the mobile phone button or talk loud for the VOX, and the call will come through. To end the call, hit the button again or let the call die, and music will start streaming if it was playing beforehand. I never attempted to answer a call while riding, and I always stopped, but it was much handier than reaching somewhere to grab the phone, which previously meant I usually missed the call. You might be able to get the VOX to interface with your smartphone, but I found it a mixed bag and didn’t use it in that manner. In addition to using a smartphone, you can pair up a Bluetooth enabled GPS or MP3 player, or hard wire a non-Bluetooth MP3 player using their included cable, though I never tested any of those options.

The BK-1 is supposed to give you around seven hours of usage, but I never rode that long at once, but in my rough testing, I got maybe five hours of music listening, done over two different days, before it started to beep at me and finally die. You can recharge the unit from your computers USB port or use the accompanying wall socket (my preference), by connecting the included cable to the rear of the headsets USB port.

The BK-1 is pretty rugged, and it survived many rain storms and rough usage. I crammed the speakers into the helmet and jammed the helmet into my gym bag, and yanked the boom this way and that regularly, and they haven’t shown any signs of wear or ill use. After a period, the stick-on Velcro pads on the helmet start to get loose and sloppy, but the speakers never popped off on me.

Note: I didn’t test their “Click-to-Link” feature, which allows casual intercom conversations with any Cardo BK-1 user nearby.

Bottom Line

The Bk-1 is primarily an intercom system which allows two or three-way conferences between other BK-1 equipped bicyclists at a range of 100-400 yards. It is also a fancy connector to Bluetooth-enabled devices, such as a mobile phone, GPS and MP3 player. You can stream music and take calls as required, and participate in a conference, opening up a vast spectrum of functionality and entertainment. I found the whole thing surprisingly enlivening, making rides fun and different, and it was especially useful when riding with my kids. After you get used to the buttons, using the BK-1 was pretty simple, and even when the system got confused, it was easy to get it rolling again. The distance that the intercom worked was highly dependent on the surroundings, and the line of sight with your partners and dense foliage caused the reception to drop down to 100 yards or less, though keeping one another in plain view helped the problem.

I liked the external ear speaker set up of the BK-1 system, as they allowed me to listen to music or participate in a conference, and still hear ambient sounds and spatial cues from my surroundings. Using ear buds, even loose ones, isolates you, and I much preferred listening to things in this outer ear manner. The speaker booms were easy to move around so that I could change their positioning next to my ear, for lots of fine tuning.

The system might be considered silly and worthless, and it’s expensive, and you need at least two of them to tango. I found it very useful, functional, feature laden, and it’s just plain fun to use, and it made rides take on a different aspect when I was using the system. It tough and rugged, and is immune to the average abuse I tossed at it, making for a great outdoor product. I have regularly used it for music streaming and getting calls (mostly music), and having the external ear speaker set up was ideal for getting the cusp between listening to a bit of background music when grinding up a trail and hearing the outside world.


  • Rugged – waterproof, dustproof and tough
  • High-tech features – VOX, DSP, PCL, AGC, echo cancellation
  • 2 and 3-way intercom between other BK-1’s
  • Mobile phone usage – hands-free music streaming and phone interaction
  • Easy to use
  • Speaker booms – allow fine tuning of placement
  • Outside of ear speakers – can listen, yet get ambient sounds and spatial cues


  • Expensive
  • Distance issue – especially in heavy foliage
  • Need other BK-1’s for intercom usage

MSRP: BK-1 $274.95 and BK-1 DUO $479.95

cardo BK-1 Specs:


  • Fits virtually all bicycle helmet
  • Lightweight Aerodynamic design (under 50g)
  • Waterproof and dustproof (IP67 standards)
  • Up to 7 hours talk time/1 week stand by
  • Universal Travel Charger 110/240V 50/60Hz Battery type:  Rechargeable Li- Polymer
  • Charging time – 3 hours
  • Omni-directional microphone
  • Hovering speakers with flexible boom for maximum biker comfort
  • Multi – functional USB jack

Multiple Device Connectivity

  • 3-Way Intercom Conferencing
  • Mobile Phone
  • GPS
  • MP3
  • FM


  •  3-way Bike-to-Bike intercom conference mode at a range of up to 500 m /1 640 feet*
  • Click-to-Link  Spontaneous intercom conversations with any cardo BK-1 user nearby

Key Functions

  • Make / Receive / Reject mobile phone calls either by voice command or at the push of a button
  • Receive in-the-ear GPS navigation voice Instructions
  • Upgradeable Software to support future enhancements/features USB cable for PC included

Advanced Technology

  • Voice-control for receiving or rejecting incoming mobile or intercom calls
  • Packet Loss Concealment: Real-Time compensation of audio losses in challenging environments
  • Digital Signal Processing Technology for advanced functionality
  • Volume-Per-Mode: Volume is set and saved at different levels for each audio function
  • AGC – Automatic Gain Control
  • Echo cancellation for increased audio clarity

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