Not exactly the best kept secret in cycling history, Shimano has been working on a new version of its top-class S-Phyre road cycling shoe for some time, and today it was officially unveiled.

Called the Shimano S-Phyre RC903, the shoe was used by Mathieu Van der Pol during the 2022 season and made a more official appearance at Eurobike in July, but even there details were sparse. Today, we finally have the full picture of what will be the best cycling shoe in Shimano's lineup.

The launch comes just two years after the release of the previous model and is touted as lighter, more comfortable, and with redesigned Boa retention cable routing.

The S-Phyre RC903W is a women's version with the same features, but with a women-specific last shape that is thinner and follows the shape and contours of a woman's foot. The RC903W will also come in a unique white and silver color scheme.

Undoubtedly related to the aforementioned improved comfort, the RC903 also gained a "refined toe box fit. This is because when its predecessor, the RC902, was released in 2020, it caused upset among Shimano loyalists. The toe box was adjusted to be narrower than the previous RC901, requiring many riders to size up. There is no confirmation from Shimano as to whether this improvement will return to the previous shape, but it is something that buyers will need to consider when making their choice.

As with the previous RC902, retention is accomplished by two Boa Li2 dials, with the upper dial securing the wrap-over strap and the lower dial tightening the forefoot. The plastic cable guide has been replaced with a fabric one, and the cable crosses twice instead of once. This halves the amount of adjustment per click of the lower dial, allowing the fit to be adjusted in smaller increments.

Other updates have also been made to the rear of the shoe. The new heel cup is visibly more integrated and color-matched to the rest of the shoe, and along with updates to Shimano's Dynalast, the shoe's material, the range of fit has been expanded. Shimano says the RC903 "accommodates a wider range of foot shapes and sizes" than previous versions.

While the previous model was available from EU36 to EU48, the new RC903 starts at EU40. It continues up to EU48, with half sizes available from 40.5 to 46.5. It is available in red, white, blue, and black.

Women's models start at EU36 and are available in full sizes up to EU44 and are only available in white fading to silver at the heel.

MSRP for each pair is $450.00/€359.95. Pricing in the UK has not yet been determined.