On the inside of the heel cup, Shimano has changed over from the silver cat tongue-like one-way fabric to printed silicone grippers and, combined with the new beefed-up heel cup and sculpted padding, offers a tangible improvement in heel hold. Shimano says it's made a few minor tweaks to the shape of the new S-Phyre, including a more gradual taper on the toe box, and improved heel hold when it comes to the engineered fit.

Working in kind with the mesh on the shoe's front third, the RC902s are quite a bit cooler than their predecessors. With a lot of shoes, I have long believed vents in the sole really on only serve as a drain for moisture as you can rarely feel any airflow coming into the shoe - that's not the case with the new S-Phyre there is, without a doubt tangible cooling on offer. During the design process, Shimano looked at forces transmitted through the shoe during significant changes in pace and saw lateral stiffness could be improved by beefing up this area of the shoe. The carbon plate on the base of the shoe is rated 12 out of 12 on the brand's stiffness scale and works in combination with the new anti-twist heel cup.

They offer micro-adjustment in both directions, have a pop release, a rubberised edge for grip and look nice, too. Boa says the Li2 are lower profile and lighter than the IP1 dials, but I wouldn't say there is much difference in function. Speaking of the Boas, the S-Phyre have the latest Li2 dials.

Shimo fabric