4iiii Viiiiva Heart Rate Monitor

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.

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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.

> Check out our buyer's guide to heart rate monitors

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.

Verdict

A strong performing heart rate monitor with useful connectivity options