Rotor launched the left-sided Power LT to create a more affordable entry point below its dual-sided Power, though oddly it was only ever sold as a complete crankset so you couldn’t upgrade a Rotor crankset you already owned.
The LT weighs just 50g more than Rotor's regular 3D+ crankset. The strain gauges are built into the crank arm and the electronic gubbins are housed in a unit on the end. It has an accelerometer so doesn’t need a magnet, making both installation and pairing a breeze.
Rotor proudly claims that the Power LT is (along with its siblings) entirely unaffected by temperature changes, meaning you don’t need to calibrate it before every ride. The meter wakes with the first light push on the pedal, so it won’t go to sleep on a long coasted descent.
The CR2477 battery is rare and slightly more costly than most, but then it lasts longer than any of other replaceable batteries we've tested recently (as well as being several times the size). We'd still recommend keeping a spare though, especially if you’re travelling as you won’t find them in many shops.
In normal, steady riding the Power LT performed very well, tracking closely with other meters and remaining consistent. Certain efforts confused it, though. Doing hill reps at 50rpm and high effort caused it to under-read by 5% compared with riding at normal cadence. And it doesn’t catch sprints very well, often showing a maximum power figure that’s lower by as much as 100-200W.
That’s not all. It’s slower to respond to changes in effort, and gear shifts usually cause power to drop to zero for a second or two, as if the clunk of the shift had upset it. That might not sound like a big deal but when you’re used to training to power using one of the slicker meters out there, it grates a bit.
As we finalised our test, Rotor announced that the Power LT left-sided crank meter is being discontinued and that it will focus on the newer INpower which is also left-sided but measures at the axle, uses an AA battery and costs significantly less. We’ll be testing an INpower very soon, but it looks like the Power LT crank meter will remain on sale in many places for a while yet.