There are hundreds of heart rate monitors on the market, many built in to smart watches and fitness monitors, but among cyclists the chest strap is still king. The latest such design from 4iiii, the Viiiiva, works well as a heart rate monitor (HRM), but there's more to it than that: rather than simply being an ANT+ or Bluetooth unit, it integrates both and also acts as an ANT+ bridge.
What does that mean exactly? Well, it can send ANT+ data through to a Bluetooth device, so a traditional speed and cadence sensor can be used on an app on your phone, for instance. Given that the CEO of 4iiii is Kip Fyfe, who was one of the inventors of ANT+, I was interested to see how this worked.
It's undoubtedly the major selling point of the Viiiiva and it certainly performs well in this regard. Connecting ANT+ devices to the phone through the heart rate monitor is simple and is done through the 4iiii app. The app itself is very easy to use, and even allows the Viiiiva to be paired through tapping it on the phone, although I did it through a regular Bluetooth scan too.
One of the slight downsides is that some apps don't currently support this multi-device connection – rather than recognising the ANT+ device connected to the HRM, they'll only recognise the HRM – but this is more to do with them not being up to date rather than any fault on 4iiii's part. Once the ride has been completed, though, it's simple to email the .fit file and upload to any app you want.
Aside from the technical details of the Viiiiva, it needs to first and foremost act as a heart rate monitor, and it does this well. For accuracy, I tested it against another chest strap and a wrist-based monitor and throughout it was only ever one or two beats different. Although not strictly scientific, it shows that it's at least as good as others on the market.
It is also simple to pair with cycle computers, and I did this easily with a Garmin Edge 810 and 3T Eye without any issues. Similarly, it connects through a standard Bluetooth connection on my phone so it can be used as a standard HRM on apps like Strava or Garmin Connect.
The fit is good and adjusts through two sliders at the back, keeping them off potentially angular parts of the body. At the front the strap connects to the unit itself through a popper on each side. I was comfortable using this after several hours in the saddle, even when particularly hot and sweaty.
At £79.99, it sits at around the same mark as the Tickr X from Wahoo, but when thinking about the price it is worth noting 4iiii's aim to frequently update its products with new firmware rather than simply replacing them. It means a larger initial outlay, but an HRM that won't need replacing for a long time and one that is always improving.
Overall, I really like the Viiiiva. If you want to simply measure your heart rate then others can be found cheaper, but if you are looking for an HRM with better connectivity, it's very good.
A strong performing heart rate monitor with useful connectivity options
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road.cc test report
Make and model: 4iiii Viiiiva Heart Rate Monitor
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?
4iiii says: "Viiiiva's innovative design captures the most sensitive of heart rates! Its advances beat-to-beat measurement gives immediate heart rate representation allowing for quick performance adjustments. And, Viiiiva bridges ANT+ sensor data to both iOS and Android smartphones."
It works well for both points. The heart rate measurement seems accurate and it was also useful as an ANT+ bridge, allowing data to be communicated to my phone.
Tell us some more about the technical aspects of the product?
* Tap to Pair
* Activity Logging
* Highly Responsive Heart Rate Sensing and Superior Beat-to-Beat Measurement
* ANT+ Sensor Bridge
* Fitness Equipment Pairing
* Display Compatibility
* Long Battery Life
* 4iiii Product Integration
* Smartphone Compatibility
* User-Friendly 4iiii App
* 4iiii Cliiiimb app updated for compatibility
Well made, with a strong strap and well placed sliders, even waterproof up to 3m.
Worked well, picked up my heart rate effectively, and as a bridge connected my ANT+ sensors to my phone.
Given the upgradability of the unit, it should last for a long time technically, and no early signs of wear.
46g isn't going to weigh you down.
The sliders are well placed and the strap is easily adjustable, comfortable even after hours in the saddle.
Relatively expensive, but hard to equate given the potential to update in the future.
Tell us how the product performed overall when used for its designed purpose
Very well, connected ANT+ features, accurately measured my heart rate, and spoke to several apps and computers when I needed it to.
Tell us what you particularly liked about the product
The ANT+ bridge.
Tell us what you particularly disliked about the product
It's quite expensive.
Did you enjoy using the product? Yes
Would you consider buying the product? Yes
Would you recommend the product to a friend? Yes
Use this box to explain your score
It does everything it needs to very well, providing accurate data and also communicating ANT+ data to Bluetooth devices.
About the tester
I usually ride: Cannondale Supersix Evo 6 My best bike is:
I've been riding for: 5-10 years I ride: Every day I would class myself as: Experienced
I regularly do the following types of riding: commuting, club rides, sportives, general fitness riding, fixed/singlespeed, mountain biking
George spends his days helping companies deal with their cycling commuting challenges with his company Cycling for Work. He has been writing for Road.cc since 2014.
When he is not writing about cycling, he is either out on his bike cursing not living in the countryside or boring anybody who will listen about the latest pro peloton/cycling tech/cycling infrastructure projects.