Solestar's carbon insoles have been developed specifically for cycling and are designed to improve power transfer and comfort when pedalling, while also reducing stress on the foot.
Chances are your body does some odd things as you pedal. A bike is designed to work with a clean, repetitive, piston-like motion, while human bodies have a less perfect relationship due to unique interactions between joints and muscles.
One particular action is called pronation which, put simply, describes how the foot and ankle roll as you push off. Excessive pronation, either inwards or outwards, can cause damage to knee and hip joints, causing muscle strength imbalances as the body attempts to even itself out
A number of inserts aim to cure this by adding angled wedges under the ball of the foot to create a neutral foot position, but Solestar's approach is a bit different. To simplify, their inserts are made from a rigid but lightweight carbon fibre shell that gives a large amount of support to the arch of your foot.
This minimises its ability to pronate (or roll) as you push down – it's an action that's essential to prevent joint damage when running, but less necessary for cycling.
Fitting the insoles is a custom process, with a pressure map of your foot being taken by selected bike fitters, podiatrists and physios. This is used to fine tune the insert to a perfect fit, and the session is included in the overall price.
Our extremely over-pronated (read: bandy-legged) tester suffers badly with knee pain when clipped in on longer rides. Results with the inserts were immediate, with massively reduced 'wobble' of the knee during the pedalling stroke and zero knee pain, even on 70-mile-plus off-road rides.
Our tester said: "With a gait like John Wayne on a fat pony, I struggle with knee pain. Other inserts have helped me, but these made a huge difference, reducing my knees' propensity to twist at the bottom and wobble at the top of pedal stroke, stabilising it and reducing stress on ligaments and joints."
Their cost is high though, and as they're thicker than normal soles, you may need new shoes too, but new knees are more expensive still. And as our tester put it: "Anything that reduces pain and long-term damage effectively is good value."