Bluetooth system allows you to talk to a ride partner over several hundred metres - but an big outlay for an uncertain benefit.
Cardo BK-1 Duo Communication System
5 10

The Cardo BK-1 is a helmet-mounted communication system that allows you to talk easily to a ride partner via Bluetooth – but the big question is whether you really need it. If it does appeal, you still have to contend with a hefty price.

I found setting up the system pretty straightforward. It takes just a few minutes. You use a Velcro strap to attach a cradle to the vents of the helmet and then snap the BK-1 unit in place. Then you attach the audio kit – which consists of two speakers and a microphone – to the helmet via Velcro mounts. I tried it on a several different lids and it was simple every time.

That's it. Then you just talk and the person (or people, if you buy an additional BK-1 Single Communication System for £195) you're connected to can hear you and talk back, just like a hands-free phone headset. The system is voice activated so it will shut down temporarily if there is radio silence for 30secs and come back to life when you start talking again (you can disable this feature).

The obvious worry was that the system would affect our ability to hear traffic sounds, but the speakers hover close to your ears rather than sitting right over them so they don't block other noises, and the microphone is foam-covered so you don't get the sound of the wind blowing over it. If someone is actually talking, it's only as loud as if they were standing next to you and chatting. Personally, I didn't feel that the system compromised safety, although you're naturally free to disagree.

The bits that mount to each helmet total 120g – so you're adding maybe half as much again to the weight of the helmet. I did notice that weight to begin with but soon got used to it.

One benefit to using the BK-1 system is that you can sit one rider behind the other and still talk. And usually when you're cycling fast, even riding side by side, you have to turn and/or nearly shout at one another to make yourself heard; that's not the case here – you just talk normally. You can be up to 500m apart and still communicate although that's in ideal conditions. If there are buildings or trees in the way, it's far less.

As well as two-way (or three-way) intercom function, the BK-1 can act as a Bluetooth headset for your mobile phone, allowing you to make or receive calls either by voice command or by reaching up and pushing a button. You can also use it with an MP3 player (let's not get into the rights and wrongs of that just now) or GPS device.

The BK-1 unit is waterproof and the Li-polymer battery provides up to seven hours of talk time. It takes three hours to recharge fully from empty.

All in all, the system works well. You might occasionally get fed up of your ride partner's heavy breathing in your ears up a steep climb, but it's easy to adjust the volume and the speakers are on flexy mounts so it's easy to move them away.

But I'm struggling to see much need for this system – in motorcycling, yes, but cycling? Don't get me wrong, it's quite good fun to use when just going out for a ride with a friend, but £335 worth of fun? Well, you have to decide that for yourself.

The BK-1 has won a Red Dot design award so maybe I'm wrong. I guess if you're in a two-up event, for example, they could be handy. If you think that they'd be useful for any other type of riding you do, fair enough, the system will perform as promised.


Bluetooth system allows you to talk to a ride partner over several hundred metres - but an big outlay for an uncertain benefit.

road.cc test report

Make and model: Cardo BK-1 Duo Communication System

Size tested: n/a

Tell us what the product is for, and who it's aimed at. What do the manufacturers say about it? How does that compare to your own feelings about it?

Cardo say, "Meet the Cardo BK-1 DUO, the world's first Bluetooth Cycling Communication and Entertainment system. The Cardo BK-1 offers simultaneous conversations via intercom between up to three cyclists, mobile phone connectivity, in-the-ear instructions from GPS devices and MP3 stereo music streaming from compatible devices. Whether you cycle alone or in a group, the Cardo BK-1 will give your favorite outdoor experience a whole new dimension."

The system works well, I'm just struggling to see a real benefit for most people that would justify the outlay. If a two-way communication system would benefit your riding, this system works well.

Tell us some more about the technical aspects of the product?

The BK-1 is compliant with and adopts the Bluetooth Specification 2.1.

Rate the product for quality of construction:

It's waterproof and sturdy enough.

Rate the product for performance:

It does exactly what it promises.

Rate the product for durability:
Rate the product for weight, if applicable:

Well, there's nothing to compare it with, really (not that I know of, anyway). it would be good if the unit was a little lighter and less conspicuous... but you could say that about a whole lot of things.

Rate the product for comfort, if applicable:

Adding 120g to the weight of your helmet is noticeable, making it just a little less comfortable to wear.

Rate the product for value:

Tricky one to judge but I think £335 is a lot to pay for something that makes communication just a little bit easier.

Tell us how the product performed overall when used for its designed purpose

It does work well if you really can see the benefit for the type of riding you do.

Tell us what you particularly liked about the product

It does what it's supposed to do.

Tell us what you particularly disliked about the product

I just don't see the need for the riding I do. I asked around and nobody else seemed to think it would enhance their riding either. If you can think of a use, please let us know in the comments below.

Did you enjoy using the product? A bit, but not especially once the novelty had worn off.

Would you consider buying the product? No.

Would you recommend the product to a friend? Not to anyone that I can think of.

Overall rating: 5/10

About the tester

Age: 41  Height: 190cm  Weight: 75kg

I usually ride:   My best bike is:

I've been riding for: Over 20 years  I ride: Most days  I would class myself as: Expert

I regularly do the following types of riding: time trialling, commuting, club rides, sportives, general fitness riding,


Mat has worked for loads of bike magazines over 20+ years, and been editor of 220 Triathlon and Cycling Plus. He's been road.cc technical editor for eight years, testing bikes, fettling the latest kit, and trying out the most up-to-the-minute clothing. We send him off around the world to get all the news from launches and shows too. He has won his category in Ironman UK 70.3 and finished on the podium in both marathons he has run. Mat is a Cambridge graduate who did a post-grad in magazine journalism, and he is a past winner of the Cycling Media Award for Specialist Online Writer.


Dr_Lex [466 posts] 4 years ago

I'll 'fess up to using a pair of walkie-talkies and headsets on a trial ride with a friend. Worked fine, and avoided the endless side-by-side/single file switching, but just felt odd. Perhaps would best suit those with rainbow-striped jerseys?

Lordfun [19 posts] 4 years ago

Had a pair of these for almost a year & must say I am an avid fan of the Cardo BK-1.

My wife and I often go on cycling trips together and using this kit enables us to chat, without the need to shout over wind/traffic noise, but at a normal conversational level. It is useful to give directions and pointing out things of interest things when cycling along a busy road in-line

A negative is that it is very line-of-sight and if one of you goes around a corner, signal drops out quickly

The battery life is good and lasts about a day. As it is voice activated to talk...my wife’s battery runs out an hour before mine which gives me a bre...  1

therealsmallboy [177 posts] 4 years ago

 4 4 4

Very witty.

Pommylump [1 post] 3 years ago

My wife and I also have this set, we have used for nearly a year and I think they are awesome.

We used to do a lot of side by side riding on cycleways with me always on the wrong side, could get scary if not concentrating and someone came the other way.

Now we ride single file much safer for me, I get a better ride as she can just draught off me when we do our ironman training rides, the battery has never gone completely flat even on our 160km rides.

Also if one of us gets a phone call we can answer the call and when it finishes we are back chatting again. I sometimes cycle with her to work 45km's then cycle home on my own so can just listen to my audio book on my iPhone.

As the headphones don't go in your ears while listening to books, I can still hear a lot that is going on around me.

P38 Pilot [1 post] 2 years ago

Bought the Cardo BK-1 Duo set for my wife for Christmas 2014.  She leads many group rides and I usually do the sweeping.  During group rides, the BK-1 allows us to easily communicate if there is an issue at the back of the pack (missed a light, got a flat, mechanical problem, washroom needed, when are we eating, etc...).  No more trying to speed up to the front to communicate this issues.  When just the two of us are riding, we can chat in normal conversation without yelling.  We can point out things we see instead of just waving are arms which usually doesn't do much.  When I ride alone in the rural areas, I enjoy listening to my iPod music (at a low volume, keeping the left ear available to listen for traffic).

I know the 500m / line of sight limitation can sometimes be a problem, but if my lady or I create a gap that stops our link, I suspect we could use our cell phones via the BK-1 headset.  I assume that as long as we are both in cell phone range of each other that the BK-1 should work.  We haven't tried this out yet, but it sounds good in theory!!!  I don't have a cell phone at the moment, so my test of this theory will have to wait.

Sometimes when we first start, the BK-1 system doesn't smoothly link to each other and other times barely breathing activates our chat!  I've changed the VOX setting and now keep it on High.  Other than that, they've toughed out some very heavy rains and keep on working.  Just unplug the electrical components and ensure they get dried out when you get home.

Great invention.  Comfortable.  Light weight.  Low profile, in fact most cyclists when seeing us talk think we are talking to them.  We have to explain that my wife and I are talking and we'll let them know when we are talking to specifically them.  Or they think we are losing our minds and just talking to ourselves:)

Can you tell I love this product?!!!