Sidi ergo 4 carbon composite mega road shoes known for their quality comfort and fit sidi shoes are loved by cyclists the world over the ever popular ergo has been refined to include a twelve carbon composite sole and techno 3 closure system light and stiff the ergo 4 is suitable for racers and enthusiasts alike to maximise energy transfer its important to have a sole thats light and stiff sidis twelve carbon composite sole is made with carbon fibre injected in a matrix of nylon the