Mio Link Review

Matt Wallis

The world of wearable tech is moving forward. Can an optical, wrist based monitor like the Mio Link release us from our constricting chest straps?

The market for wearable tech is on the rise. Some of the world’s most innovative companies are now vying for a place on our wrists, feet and even our eyes. Simon Tuck wrote a great piece a few months ago, (link) predicting the future of such tech and revealed that a surprising amount of science-fiction is actually achievable in the here and now and the Mio Link is part of that revolution.

The Mio Link offers the chance to get rid of those constricting chest bands

It got me thinking. When riding, do I really need my heart-rate monitor on my chest, potentially constricting my breathing with a straight-jacket like strap? Wouldn’t it be cool if someone could take the tech from premium items like the Apple iWatch and distilled it back to what’s really useful right now? Well, the people at Mio Global have done just that with their Link heart rate monitor.

We now live in an age where devices can judge heart rate with claimed accuracy by measuring the change in skin colour as your blood passes through. The Mio Link uses this technology, coupled with Bluetooth Smart and ANT+ technology to broadcast this data to your cycle computer or smart-phone.

The silicone bracelet has a certain sporty appeal to it. It’s no bulkier than a sports watch and doesn’t feel heavy when on the wrist. The perforated strap allows for great customisation when fitting it, which is useful to get the right contact for the optical sensor to sit snugly and work its magic. Mio have their own charging dock for the link, using a magnetic strip to easily connect the link to a standard USB charger. There are no ugly ports on the link itself which adds to the sleek look of the monitor.

The Mio Link is a minimalist looking strap, what is going on on there?

Operation is simple too, a press of the Link’s only button turns a green light on. This starts to pulse as the optical monitor does its thing, eventually settling to a light blue flash every few seconds. The colour of this flash will change based on what heart-rate zone you are in. After this, it’s simply a case of connecting to your device through either ANT+ or Bluetooth using the normal methods.

Connecting to a smart-phone allows you to use Mio’s Go app to customise your heart rate zones. You can even change the colour which flashes in each zone. Glancing at your wrist while on a ride quickly tells you which zone you’re working in if you haven’t got the number in front of you on your cycle computer screen. Having this smartphone functionality also allowed me to install a few other apps which are compatible with Bluetooth HRM’s.

I’ve settled on using the Heart Rate app by Dawson Toth on the App Store to get a quick update of my rate, and how much charge is left in the Link. Dabbling with the Sleep Rate app has also opened up my eyes to some really clever apps designed to record and analyse the quality of your sleep. Useful for a cyclist who’s always looking to be well-rested!

It took a while for our reviewer to find the optimal position for the Mio Link

Coupling the Link with the Strava iPhone app has also given me quick, easy HR data on my commutes and errand rides. Great for those who like to see all rides influencing their Fitness/Freshness score without having to wear a chest based monitor!

I must admit after the first few weeks using the Link, I had some reservations with the monitor. On the start line of my first race, I noticed a numbness forming in my left hand. The monitor, which had fitted snugly when I first put it on was now very tight and constricting blood and nerve flow to my hand! I loosened off the strap, but it did make me wonder whether joint swelling (a normal occurrence for some riders) would become a major issue. Fortunately I’ve not had the same problem in the two months since so can confidently chalk that as a one-off.

The other issue I noticed at various points both on normal and training rides my heart rate would plummet to around the 50bpm mark at seemingly random points. At first I couldn’t work this out. Mio advise riders to keep the strap nice and tight but I think I had taken this too far and was now constricting blood flow slightly.

I experimented with other positions, trying the optical sensor on the other arm, then on the base of my wrist to no avail. Eventually, moving the monitor to about three quarters of the way down my forearm (a few inches above my wrist) began to bear fruit.

Since adopting this position the accuracy has shot back up to what I’d expect from a heart rate monitor. I’ve now gone countless commutes and many long rides without the rate plummeting and am very happy with how the monitor is performing. With this position I’ve had some issues with the monitor slipping slightly while riding on cobbled and rough roads. CX and MTB riders may need to further tweak the position of the monitor to address this issue but 99% of road rides are perfectly fine.

The Mio Link and our reviewer in action at the Velothon

The only other minor issue I’ve noticed with the Link regards battery life. Using a Link gives you one more device to charge before a ride and if you’re riding sunrise to sunset on an epic adventure the battery simply won’t go the distance. I’d say I tend to get around 5-6 hours out of a single charge as opposed to the 8-10 claimed by Mio. I’ve got around this by simply turning the meter off while at coffee (and some lunch) stops. However, it nags at me when I see other riders increasingly topping up their Garmin 1000’s and other devices mid-ride nowadays. One of the first features I’d expect with modern tech would be to comfortably last the day!

These issues aside, I’ve been very impressed with the Link. It provides a real, versatile alternative to chest-based monitors and unlocks some great features off the bike when paired with a smart-phone. Once I’d resolved my accuracy grumble by changing then monitor’s position it has been solid and reliable. At around £60.00 you’ll be spending slightly more than a chest based monitor with similar features, but for those who find these constricting the Mio Link is definitely an option worth investigating.

Mio Link

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