The key to the M230s is the Custom-Fit technology. Unlike the more expensive ‘shrink to fit’ shoes in Shimano’s range, ‘Custom-Fit’ refers to their mouldable insole that needs to be ‘cooked to fit’ at a Shimano specialist dealer.
The nice guys at Strada Cycles in Bristol took care of the shoe-in-oven part for us, and ensured the fitting process was carried out properly. Once we got them out of the oven and onto the trail, the difference was certainly apparent. There’s a lot more support and the fit around the heel and arch of the foot is much better.
The M230s are seriously comfy shoes. The sculpted fit means you don’t have to crank the straps quite so tightly, because there's less movement within the shoe, thanks to the precise fit.
The carbon reinforced plate in the sole allows for efficient power transfer to the pedals without being uncomfortably stiff but can get a little slippy should you unclip while trying to get your foot back in.
The upper features a rubber moulded heel and toebox area that do a good job of fending off debris or floor strikes if you do slip a pedal. The upper meshed sections promote good airflow but won’t keep water out.