Polar CS400 heart rate monitor review

Multi-function computer & heart rate monitor

Our rating 
2.5 out of 5 star rating 2.5
GBP £175.00 RRP | USD $404.10
Polar CS400 Heart Rate Monitor

Our review

Potentially clever piece of kit, but operating system lets it down
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Polar’s mid-range, bike-mounted computer and HRM, the CS400 is a curate’s egg that needs time and effort learning its quirks to get the best out of it.


The CS400 is small and light, and can be mounted either on the bar or, as we prefer, on the stem.

The buttons are large and easy to hit, and the read-out is clear and can be read while bumping along. Its overall shape is very appealing, too.

However, we were disappointed at how user-unfriendly the operating system was. Inputting the setting is relatively straightforward, but toggling through the options to arrive at your target display is not.


We found it unreliable too. We’ve wiggled the fork/wheel sensors to within the recommended 4mm range, moved the head unit to see if the signal was being blocked by the stem, but to no avail. Sometimes we get a reading, sometimes not.

Product Specifications


Name CS400
Brand Polar

Available Colours Red/Black
Further Features Back Light Low Battery Indicator Water Resistant
Time Functions Clock Riding Time Stopwatch
Activity Type Cycling
Heart Rate Monitor Functions Current Heart Rate Max Heart Rate Miniumum Heart Rate
Watch Functions Alarm Date Laps Times Stopwatch Time
Altimeter Functions Daily Ride Time Total Ride Time
Manufacturer's Description For demanding cyclists. CS400 is the choice for cyclists with a competitive attitude. Track your ride with wireless sensors, prepare your detailed training programme easily with Polar ProTrainer 5 software and use the incline measurement to adjust your cycling effort accordingly. Buttons designed specifically for cycling plus a big display help you to track your performance even at maximum speed.