With the summer cycling and triathlon season here, those of you looking to upgrade your wearable fitness technology are probably looking at either the Mio Link or the Scosche Rhythm+ optical heart rate monitors to ditch your cumbersome chest strap.  After using both products as well as the chest strap extensively, I thought I’d go through a comparison of the products so you can make a better informed decision when it’s time to purchase.

Hardware Similarities

To start, both the Mio Link and Scosche Rhythm+ use a dual radio ANT+ and Bluetooth Smart so you can connect your ANT+ watch or bike computer to the monitors, as well as your smartphone running your favorite fitness app.  They both use the standardized Heart Rate profile to send a heart rate number to the device of your choice.  With both devices connectivity is simple and easy. 

Both heart rate monitors use Optical Sensors, although differently.  This is where the two devices begin to part ways.  The Mio Link uses 2 green LED’s and a photo sensor to illuminate your capillaries, while the Rhythm+ uses 2 green and 1 yellow LED in addition to a photo sensor.  The additional Yellow photo sensor on the Rhythm+ is designed to improve accuracy on darker skin tones.

Hardware Differences

Mio Link is worn just above the wrist bone.

The two devices have clear differences.  The Mio Link is designed to be worn above the wrist bone and for smaller arms, all the way up to the forearm, whereas the Scosche Rhythm+ is recommended to be worn on the Forearm for best accuracy, but can be worn anywhere on the arm – wherever fits best! 

There is a clear form factor difference between the two products with the Mio link sporting a nice looking, sexy, stylish co-molded wrist watch style band with a removable pod that can fit into 2 different sized wrist bands.  It also uses a magnetic charging unit which some have commented that it can fall off the charging station easily.

Rhythm+ has a single housing unit that comes with 2 different sized washable bands which Velcro around your arm.  Rhythm+ uses a clip on charging unit which has a sturdy connected feel.


This is where there seems to be a clear winner.  The Scosche Rhythm+ shines in performance, utilizing the Valencell Performtek biometric technology (hence the yellow LED).  Based on my testing, the Rhythm+ is right on par with a chest strap while riding the Mountain Bike on some very technical trails.  The Mio Link, while good, cannot keep up in more than one instance.  It tends to be a bit slow to measure peaks and troughs.  I’m not exactly sure why, but based on my experience it could be because either the algorithms are not optimized for accuracy, the 2 green LED’s are not adequate for my skin tone (white), or that the wrist is just not a great location to pick up reliable heart rate signal data.  The wrist has lots of bones and other factors which create “noise” in the raw data signal, which is why from myTREK to Rhythm+ Scosche has avoided the wrist (for now) for gathering heart rate data.   

Scosche RHYTHM Plus Available HERE!

Scosche RHYTHM Plus Available HERE!

Another troubling thing with the Mio is that I have seen Bluetooth disconnects on more than one occasion.  In addition, it does not always reconnect and sometimes requires power cycling the wristband – ouch!  If you are wearing it and you see a “Flatline” this is indicative that it could be a Bluetooth disconnect which is difficult to diagnose and correct.  We’ve been through that at Scosche as I was testing the Rhythm+ and we were able to create a fix within the products firmware. 

See the green flatline?  I'm fairly certain that was a bluetooth disconnect which I've seen on multiple occasions with the Mio Link.  To fix it usually requires power cycling the armband - a real bummer!

See the green flatline?  I'm fairly certain that was a bluetooth disconnect which I've seen on multiple occasions with the Mio Link.  To fix it usually requires power cycling the armband - a real bummer!

Outdoor Straight Line of Site Range Tests

Mio Link = 89 feet

Bluetooth Smart Chest Strap = 209 feet

Scosche RHYTHM+ = 319 feet


                Mio Link $99.00

                Scosche Rhythm+ $79.99


Obviously I am biased, working for Scosche as a consultant and product tester, I think the Rhythm+ is a clear winner.  I see where we have made accuracy improvements where the Mio Link has not, and I value accuracy over most things.  I have seen the mistakes of previous generations of optical heart rate technologies and I know it is a difficult arena to play in.  This is why I know that the Rhythm+ is the armband you will be happier with for your training.  It performs better is less expensive, and more “up to date” with current technology than the Mio Link.  

More Information on the Scosche Rhythm Plus.

DC Rainmaker's Blog on The Rhythm+