In The Know Cycling

While very similar to their immediate predecessors, the latest Shimano S-Phyre RC903 road cycling shoes have changes below the surface that make them noticeably better performers and more comfortable than their highly-rated predecessors. I rank these new S-Phyres among the best cycling shoes we’ve tested, and are the ones I’m most likely to put on for a ride on the road or trainer.

It looks like little has changed

On the surface, it looks like Shimano has made only superficial, small modifications to the shoes. Most obvious is the RC903’s use of multiple tiny eyelets to direct the closure lace in a figure 8 pattern in the area above your toes instead of the regular-sized plastic guides the lace runs through on the previous RC902 model.

Changes to the lace guides and fabric near the toes on the RC903 (left) are the most obvious.

There’s also a stretchy, sock-like fabric running atop your toes between these front eyelets; the RC902 used the same upper material in this area as in the rest of the shoes. And if you look closely, you’ll notice a modified pattern of pin-hole-sized perforations across the uppers of the RC903.

On both models, the heels look to be protected with almost the same bumper profile and thickness as before. True, the new RC903 bumpers have slightly raised ribs along the sides of the heels, and the entire outside surface of the shoes from the ankles back has an appealingly shinier and perhaps more reflective finish than before.

The RC903 (above) adds some ribs and shine to the similarly profiled heel bumpers.

But the design, materials, and vents in the shoe’s bottom or “outsole” appear unchanged. Likewise, the same dual, Li2 dial BOA closure system with the upper dial attached to the end of a crossover strap still controls the fit of the shoes.

And the signature blue color that has long made this S-Phyre stand out in a crowd remains along with classic black and white options and my favorite, the In The Know Cycling red. (How did they know to do that?)

Even the single-digit increase in the model number from RC902 to RC903 and the almost identical weight (242 to 244 grams on my scale for a single EU43 shoe) suggests little has changed.

Wearing the Shimano S-Phyre RC903 reveals big changes

Going below the surface and actually putting my feet into and riding the new Shimano S-Phyre RC903, I immediately noticed two changes that make them as good as any road cycling shoes we’ve tested and better than most for both fast, hard group rides and races and long days of endurance riding.

I previously rated the RC902 model equal to the best road cycling shoes for their overall performance. But while their snug fit and stiff outsole seemed to transfer your leg power to the pedals as efficiently as any shoe we’ve worn, I and my fellow tester Nate found them less comfortable than other shoes on 3+ hour rides.

The Shimano S-Phyre RC903 changes that. They have more room both above and to the sides of your toes than the earlier model while still giving you a glove-like fit with no pressure points from the forefoot back. This makes them as comfortable as any shoes I’ve reviewed on 3+ hour rides.

And while I’ve not yet worn them outside on the warmest summer days, I never found the prior models hot in those temps and expect the softer, permeable fabric above your toes will allow them to breathe even more inside the RC903.

The second consequential below-the-surface change comes at the back of the shoes. On my feet, the RC903 feels more tailored to the shape of my heels from the middle – or just above where the heel’s width begins to decrease – to the top than the prior model. The lower heel cup volume had always been comfortably snug, which seems unchanged in this latest model.

This heel cup reshaping gives me the sense that the shoes are more connected to my heels than ever during the up and forward quadrants of my pedal stroke. At the same time, I didn’t experience any challenge getting into and out of the RC903 or any change in comfort at the heels while cranking on the pedals.

Even with the added room for your toes, these Shimano S-Phyre shoes aren’t as wide as the new top-of-the-line Specialized S-Works Torch in the toe box, forefoot, or heel cup areas. That’s a plus for me as I found the Spech too roomy for my EU43 or US 9D size feet to get optimized power transfer.

On the other hand (other foot?), my fellow tester Nate who wears the same size and whose feet measure just a couple of millimeters shorter and narrower than mine, prefers the Torch’s fit and can still drop most anyone he rides with.

Shimano also makes the RC903 in a men’s wide that adds 3-4mm to the forefoot and probably is more similar in roominess up front to the Torch without the latter’s wider heel cup.

As with most shoes and cycling apparel in general, we tend to find and stay with the brands that seem to fit us best. I’ve tested a dozen brands and fit well in many of them, but I prefer the last of Shimano road and gravel shoes. The same goes for Nate, who wears Shimano MTB shoes but prefers the wider fit of the Specialized Torch road shoes.

If you’re new to high-performance road shoes and know that the proportions of your feet fall somewhere in the middle of the bell curve, the Shimano S-Phyre RC903 is definitely a shoe worth ordering and trying on.

The RC903W has a different last

Shimano makes a women’s version of this shoe, the 903W. My fellow tester Aiyana did a few dozen rides in both the Shimano RC903 and RC903W shoes in her size EU 41.

Shimano didn’t just take the same RC903 model, slap a “W” on the name and offer the shoe in someone’s view of feminine colors. Instead, the RC903W has a different last and fits differently. It is only offered in white, which you’ll often see some of the fastest male and female riders and racers wear.

Aiyana, a former racer and still a very fast rider, had a similar experience to mine while wearing the RC903 on her feet. The shoes felt lightweight, formed to her feet well after cranking down the dials a couple of times before starting her ride, snug on the heel, and comfortably roomy in the toe box area. All of this led to excellent power transfer with the right arch support in place.

She added that the RC903 performs best in 50-90F/10-30C temps. Below those temps, the air vents in the bottom of the soles cool her feet a bit too much. On those days, she wore either toe or shoe covers.

Aiyana also liked the matte black color and subtle gloss effect on the heels of the RC903 shoes she tested. She praised the upper’s leather-like feel.

In the same size RC903W women’s model, she experienced less room in the toe box. The heel cup also felt tighter than in the RC903. Overall the RC903W felt a bit narrower and shorter than the men’s version.

It did, however, feel to Aiyana that the RC903W stretched to fit a little more comfortably during high-intensity rides and on warmer days. But on easier rides and in most temperatures, she could feel different last characteristics between the men’s and women’s versions of these shoes.

Commonly, shoes with different lasts will fit differently in the same size. Shimano’s men’s and women’s size charts led her to the EU41 size models in both shoes. Based on Aiyana’s experience, unless you have relatively narrow feet, you might want to try a RC903W in a size larger than the size chart recommends.

Of course, white shoes aren’t for everyone. Personally, I think they look sharp. They do require a bit more care to keep clean. This 903W, only available in white, does clean up quite well with the kind of hand-sanitizing towelettes many of us used during the coronavirus that are still widely available.

What Shimano could still do better

There’s little that I don’t like about the RC903s. Shimano has been one of the leaders in giving you pads of different thicknesses that you can velcro to the insole for more or less arch support. However, even with the right pad in place, I still find the Specialized Body Geometry insoles give me a smoother transition to and from the arch and along the full length of the insole.

And while I credit Shimano’s design of a crossover strap as part of the upper closure for giving me a precise, pain-point-free fit, I find you do need to be mindful to place it not too far above or below its intended position before cranking the Boa dial to get the most even pressure across your midfoot.

The Shimano S-Phyre RC903’s USD $450, £350, €407 price is also no bargain but is no more than other top-tier road cycling shoes. It’s available at these links to BTD (BikeTiresDirect), Performance Bike, and Sigma Sports.

You can compare our reviews and ratings of the Shimano S-Phyre RC903 and competitively performing models in my review of the Best Road Cycling Shoes.

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