For more than a decade the various guises of the Garmin Edge have been the go-to head unit for cyclists around the world, and the latest version in the 800 series is aiming to further embed itself as one of the best cycling computers in today's market.
The 840 (along with its non-touchscreen sibling, Edge 540) has been updated for the first time in four years, and as well as adding another '10' onto the previous iteration, the 830, it marries together many of its much-loved previous features with that of the newer and larger Garmin Edge 1040.
