This new GPS-enabled bike computer is a seriously addictive piece of hardware. For a start, there's no wheel measuring or cabling to faff about with - just zip tie on the stem or bar mount provided, clip on the mobile phone-sized unit and give it a few seconds to lock onto local satellites for a fix.
The computer provides speed, distance, heart rate, altitude, gradient, compass heading, lap stats, time and calorie expenditure data. Cadence is an option for £35 extra too. The unit also supplies max and average data and the display can show from three to eight data fields (including a scrolling map option). It also has 'Virtual Partner' and pace options so you can race yourself or set a training target to reach.
Once home, the software provided lets you study your route and all the ride data in map, customisable multi-layer graph or table form on a PC. It's even accurate enough to show different lines on the same trail in steep wooded valleys. A beta Mac version of the software is also available from the net. The battery life is relatively short though and one unit we tried (out of three) occasionally just wouldn't power up. These are minor glitches though.