The Shimano S-PHYRE XC903 is the cross-country race shoe Shimano's World Cup riders use, and the stiffest off-road shoe the company builds. It suits XC racers and marathon riders who want nothing lost through the sole.

The full carbon sole carries a stiffness rating of 10 out of 12, with an aggressive lugged outsole and mounts for toe spikes when you end up running. Dual BOA Li2 dials adjust in both directions on the move, and the surround wrapping upper pulls both sides of the foot together instead of using a traditional tongue, which spreads pressure rather than concentrating it. Construction is deliberately minimal to keep weight down.

Key features

• Full carbon sole, Shimano stiffness index 10 of 12
• Dual BOA Li2 dials with 2-way micro-adjustment
• Lugged outsole with toe spike mounts
• Surround wrapping upper for even hold
• Anti-twist stabilising heel cup
• 2-bolt SPD cleat pattern, cleats sold separately

Sizing runs narrow and there is a wide fit in the range. Worth trying a pair on before you commit.