These lucky riders were able to put the new computer to the test. DC Rainmaker gave the M450 a shining review, while reserving the right to retest in colder, darker winter months when gloves, shorter sunlight hours, and dipping temps change things a bit.
Polar, famous for their sports watches and fitness monitors, already has the V650, which does just about everything you could ask of a bike computer, but its multitude of features are reflected in its price, which comes in at $320. The M450 is set to cost $170, positioning it as a solid computer for someone who wants more than basic speed and distance. 
The M450 gives you speed tracking, distance, and route via GPS, as well as a barometer for precise altitude readings, but the little device really starts to shine when you connect sensors to it for cadence and heart rate. It’s Bluetooth Smart so it can connect with your phone, however it won’t connect with all third-party sensors (the Keo Power pedals are one named exception that does work with the M450), but it doesn’t work with PowerTap, and doesn’t have ANT+ (Polar claims because that’s because that tech is proprietary to Garmin).
Working in part with the Polar Flow data platform, you can run a quick test or two to find out what exactly needs work, and then design your own training plan. The Fitness Test measures your resting heart rate and heart rate variability, and takes your weight, age and height into account.
You also need to include a self-assessment of the previous six months of training so, of course, be honest. The test takes about five minutes, and the result is your OwnIndex, a prediction of your maximum volume of oxygen (VO2 Max), how much oxygen your body can use, based on your body weight, in one minute. This is a measurement of your cardiovascular fitness — how long it will take before you can’t catch your breath, your muscles are screaming, and you give up.
To see your data over time, you can use the Polar Flow app (free for Android and iOS) and the Polar Flow website. There’s also Polar Flow for Coach, which is great for teams, riders just starting out, or those working with a personal trainer. It has a training benefits analysis for the week, month, and year, as well as a calendar for use as a training diary and planner, and it allows a third party to view full training logs including heart rate information and power outputs.What’s more, they plan to connect Strava to Polar Flow by the end of October 2015. 
You can customize the info on the M450’s almost glareless backlit screen to show just what interests you. The twist lock system for the mount, which is the same as for the v650, unfortunately doesn’t work with quarter-turn third-party mounts. On the plus side, the buttons are large and logically placed on the side to navigate menus and on the top to confirm.
It charges via a waterproofed micro USB port with a stated battery life of about 12-17 hours. So the long and short of it is, the M450 is a powerful little bike computer with a good platform backing it, but to get the most out of this item you’re going to want a heart rate monitor.
Considering the quality of the computer itself and the integrated coaching features that come with Polar Flow for Coach, the M450 can give users the same results as some much more expensive computers. It is set for release later this summer.
