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4iiii Viiiiva Heart Rate Monitor



A strong performing heart rate monitor with useful connectivity options

At every product is thoroughly tested for as long as it takes to get a proper insight into how well it works. Our reviewers are experienced cyclists that we trust to be objective. While we strive to ensure that opinions expressed are backed up by facts, reviews are by their nature an informed opinion, not a definitive verdict. We don't intentionally try to break anything (except locks) but we do try to look for weak points in any design. The overall score is not just an average of the other scores: it reflects both a product's function and value – with value determined by how a product compares with items of similar spec, quality, and price.

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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.


A strong performing heart rate monitor with useful connectivity options 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

Rate the product for quality of construction:

Well made, with a strong strap and well placed sliders, even waterproof up to 3m.

Rate the product for performance:

Worked well, picked up my heart rate effectively, and as a bridge connected my ANT+ sensors to my phone.

Rate the product for durability:

Given the upgradability of the unit, it should last for a long time technically, and no early signs of wear.

Rate the product for weight (if applicable)

46g isn't going to weigh you down.

Rate the product for comfort (if applicable)

The sliders are well placed and the strap is easily adjustable, comfortable even after hours in the saddle.

Rate the product for value:

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.

Overall rating: 8/10

About the tester

Age: 27  Height: 6 ft  Weight:

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 is the host of the podcast and has been writing for since 2014. He has reviewed everything from a saddle with a shark fin through to a set of glasses with a HUD and everything in between. 

Although, ironically, spending more time writing and talking about cycling than on the bike nowadays, he still manages to do a couple of decent rides every week on his ever changing number of bikes.

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philhubbard | 8 years ago

I know it may be a stupid question but are the poppers the same as one the Garmin softstrap, Polar HR and Mio chest strap? Sounds silly but I already have all these so having replacements lying around all the time is a bonus

PhilipA replied to philhubbard | 8 years ago
philhubbard wrote:

I know it may be a stupid question but are the poppers the same as one the Garmin softstrap, Polar HR and Mio chest strap? Sounds silly but I already have all these so having replacements lying around all the time is a bonus

This isn't a new product as I have had one for a few years without any issues alternating between the supplied strap and a Garmin strap so they are the same popper layout.

tritecommentbot | 8 years ago

Game changer for a lot of people if Strava supports it. Means that some people trying to decide between using Strava's own app (+Premium for Live) on an iPhone (I say iPhone as they all do not have ANT+) or buying an Edge 1000 will possibly just go for the app/iPhone instead. Battery is good enough for most rides, and most people are fair weather riders anyway. I was making this choice a couple of months ago and went for the Edge 1000 because the ANT+ dongles on the market were designed for the old iPhone connectors, which meant I needed an adapter for the ANT+ connecter on the lightning port of my 6+. So you'd have ended up with a ridiculous looking setup and one that I'm not sure would have been entirely stable connection wise. I don't really like maps on the Garmin Edge 1000 and when I'm stuck I actually pull out my phone and get Google Maps going. It can be hard to read the Garmin maps in dense city areas, but it's a nice visual guide out in the back roads. Turn by turn works great but you need to get a route plotted first on it and it's a bit pants compared to plotting a route on Google Maps so often I don't bother. You can pay a monthly fee to to make it easier but again, that's a monthly fee. I digress, but these issues are all connected. The ANT+ bridge here is a stepping stone at the heart of a war between two devices that's going to really kick off in the coming years. (I call it a stepping stone as it will be redundant after Apple add ANT+ to all their models. Some Android phones already do). I'm in two minds about the phone replacing cycling computers. People statistically like phones large these days for reading books, using as a tablet, gaming etc. Like myself. But that adds bulk. On the other hand you have better mapping and visibility and it's actually less weight overall on the bike as you're taking one device instead of two. Waterproofing and capacitive touch then are the hang ups which will need better case design than we have at present. Battery isn't really such a big issue as people make out. You can boost the battery life of any device with accessories, and I'm hoping we'll see some really smart lightweight charging come to bike accessories in the coming years. 

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