The 2019 SHimano RC901 road shoes have been updated from the 2018 S-Phyre RC9
The new RC901 have a number of improvements
A heel cup has been modified to be more forgiving of various foot shapes
An important change makes the shoe more aerodynamic: The mesh panels have been replaced with generous perforations in the material. This helps prevent the material from creasing so there's no increase in wind resistance with wearing.
The larger perforations at the ball of the foot provide some material flex = something that will be welcomed by a rider on a hot day with swollen feet.
Read more about RC901 features on the BikeExchange Review
https://www.bikeexchange.com.au/blog/2019-shimano-rc901-sphyre-road-cycling-shoes-first-impressions
FEATURES CONTINUING FROM THE PREVIOUS VERSION OF THIS SHIMANO SHOE
- Unified sole and upper construction sets a new level of fit, pedaling stability, rigidity and weight reduction
- Close to foot last shape with a narrow bottom, rounded heel and slim toe box
- Wide range fit adjustability accommodates various shapes of feet
- Dual independent Boa IP1 dials allow quick and precise micro-adjustment
- Quick dry 3D mesh controls humidity
- Built in drainage holes for rainy conditions
- Optimum linkage of air flow between upper, insole and outsole
- Durable high density foam. Curved cup insole with adaptable arch pads optimizes lateral angle of heel bone
- Silvadur™ Intelligent Freshness keep insoles fresher longer