4iiii1055800

£379

If weight is a worry, the 4iiii is your meter. Incredibly, it adds just 9g in single-sided guise. In testing we were generally impressed with its performance, the app allows you to easily update software and is ANT+, Bluetooth and smartphone compatible. Our version recorded left-hand side data only, but you can upgrade to dual-sided, with the option to send 4iiii your own crank or crankset to have the unit added, saving cost.