Shimano S-Phyre RC903 review: can you spot what’s new?

The top spot in the Shimano road cycling shoe lineup is always well-regarded and frequently seen in the professional peloton. The previous generation hit the market two years ago and brought with it extensive changes including an updated fit. Although that detail did take some adjusting for long-time fans, we found it good enough to claim a spot in our best cycling shoes buyers guide.

Now, after a season on the feet of Mathieu Van der Poel, Shimano is making an updated version available to the rest of us. Tech Specs: Shimano S-Phyre RC903Price: $450. 00 / €359.

95Sizes: EU 40-48 (half sizes available 40-46. 5)Weight: 252g per shoe (Actual, size 44)Colours: White, Blue, Red, Black The Shimano S-Phyre RC903 does not represent any drastic changes. Instead, Shimano continues to leverage the data gained from the brand’s proprietary Bikefitting.

com pedalling analyzer as well as feedback from professional athletes and customers. The details have seen small adjustments and new solutions only where needed. That means the same basic questions remain.

There’s no doubt that anyone looking for a top-shelf summer road cycling shoe definitely has Shimano on the shortlist. We’ve spent time riding in a variety of situations to find the strengths and weaknesses of this latest option from Shimano. Keep reading to see if the S-Phyre RC903 is the right shoe for your riding.

There’s gorgeous textures and colours along with updated graphics but there are also other, deeper, changes (Image credit: Josh Ross) Design and aesthetics There are times when writing the section about aesthetics in a review is a joy. This is one of those times. The Shimano S-Phyre RC903 is a gorgeous shoe as long as you don’t mind standing out.

Shimano doesn’t use fancy colour names and instead lets the red, black, blue, or white do the talking all on their own. Even in pictures, you can see that if there was ever a time a brand should use a fancy colour name, this is it. The options are vibrant and rich with pearlescents in some spots and metallics in others.

There are textural shifts and every stitch and detail looks purposeful. There’s also a monochromatic style that is almost straight out of an art school colour theory class. If you recall the previous generation shoe, most of this isn’t totally new.

There are some updates though. In the iconic Shimano blue, the same metallic hue covers the bulk of the centre but now it extends all the way across the toe box. At the same time, the use at the heel has actually decreased a bit.

As you move backwards there’s now a gradient shift into a slightly darker hue with a series of lines and a pearlescent colour shift mixed in. The colour and lined texture also continues into a slightly revised external heel cup to finalise the rear of the shoe. While many brands choose to integrate the plastic support below the outer skin of a shoe, it’s a point of pride for Shimano.

The brand specifically calls out the feature as a way to limit twisting of the foot during high-cadence, or high-torque situations. The upper portion of the heel supports that further with an opening narrow enough that there’s no need for extra grip beyond thick padding. Image 1 of 5Only a small amount of the carbon sole is visible from the outside (Image credit: Josh Ross)Image 2 of 5A big portion is covered by the wrapped exterior of the shoe (Image credit: Josh Ross)Image 3 of 5Look inside though and you can see that the carbon covers the entire bottom (Image credit: Josh Ross)Image 4 of 5Some of the plastic covering extends up to protect the toe from tyre rub (Image credit: Josh Ross)Image 5 of 5At the rear you can see how easy it is to replace the heel pad (Image credit: Josh Ross) As you move down to the bottom of the shoe, Shimano actually reverses the trend at the heel.

While many brands have the carbon on full display, Shimano almost completely hides it. The replaceable heel pad sits proud with the heel cup surrounding it then, where you would expect to see carbon, you instead find the reinforced micro-fibre leather wrapping coming together in a centre stitch line. It’s not until you move to the forefoot that Shimano’s stiffest available sole starts to show.

Even at the forefoot, the appearance of carbon is rather limited. If you pull the insole you can see that the entire bottom of the shoe, even more than many brands, is solid carbon. Externally though, there is a decorative weave under the cleat mounting position that extends around the front vent and not much else.

Further limiting the carbon you see is a colour-matched plastic which, to the credit of some smart designer, extends over the front of the toe to protect against tyre rub. While there are many details that see Shimano following a different path, the adjustment system isn’t one of them. Shimano was one of the first brands to use the BOA Li2 dials but at this point, many brands have now followed suit.

The Li2 sits at the top of the BOA offerings and they appear on a variety of high-end shoes. It’s not always a given but the Li2 shows up when performance comes first. Compared to other BOA dials, the Li2 has the smallest adjustment per click and adjusts both forward and backwards.

They also pop to unlock and pull the wire from both sides simultaneously. Though Li2 dials are somewhat common at this point, Shimano does manage to use them in a unique way. Instead of two sides of a shoe meeting in the centre, Shimano uses a single piece of fabric.

It’s cut and wrapped around the shoe and the outside sits under the opposite side with BOA dials pulling everything tight. The upper BOA handles a wide strip of fabric that effectively becomes a strap across the upper part of the foot. The lower BOA adjuster then takes care of the lower section of the foot with a back-and-forth pattern that extends towards the end of the toes.

Compared to the previous generation, this section of the shoe sees a new lacing pattern and the removal of plastic cable guides. Image 1 of 2The old plastic guides are gone and the lacing pattern in the front is totally new (Image credit: Josh Ross)Image 2 of 2Although most of the guides have disappeared, there’s still two left (Image credit: Josh Ross) Performance Over the time I’ve been riding a bike, I’ve encountered a lot of love for Shimano shoe offerings. The brand is a frequent recommendation for almost every style of shoe they offer.

When it comes to the road shoes, I also absolutely love the style. Just in case it didn’t come through above, Shimano blue brought to life in a cycling shoe is a thing of beauty. As I was reviewing these though I struggled a bit to pick out how the Shimano S-Phyre RC903 stands out from the competition.

There are certain things that are an easy win, you can mark the BOA Li2 dials in that category. I have little time for style over substance and high-end cycling shoes shouldn’t get anything lower in the BOA portfolio only for the sake of style. Otherwise though, in a sea of ultra-stiff and comfortable road cycling shoes, what is truly different?One thing that contributes to that feeling is the small differences between the RC902 and RC903.

It’s easy to feel a little jaded when a shoe that essentially feels perfect gets a replacement with only subtle upgrades. Externally, the two shoes are so close you have to see them next to each other. There are some big differences internally though.

In the toe box, you will find more space vertically and a rounder profile. Image 1 of 3Every brand has a stiff carbon sole and they start to blend together a bit (Image credit: Josh Ross)Image 2 of 3One of the ways Shimano itself apart is with tons of cleat adjustability (Image credit: Josh Ross)Image 3 of 3The real star of the update is the slightly revised toe box with lots of volume vertically (Image credit: Josh Ross) I’m not sure anyone has ever complained about more room in the toe box so, I’ll call that a win. I didn’t actually notice it though.

Instead what I noticed was that the changes to the lower BOA lacing do a great job of holding the front of your foot in place. Part of what makes that work though is the extra space. It’s a better overall system and you can really notice the way it keeps your toe from feeling crammed into the front of the shoe during long rides.

The other very noticeable thing about the Shimano S-Phyre RC903 is how precise they feel when climbing. As you press down on the pedal it feels like a very direct connection between the cleat placement and the forefoot. If you are thinking this could easily turn into an issue, that’s true but it didn’t in my time testing.

Instead, it’s the best kind of dancing on the pedals feeling. Image 1 of 4The external heel cup and the thick bolstering keeps your foot from twisting and there’s no need for any kind of grip material (Image credit: Josh Ross)Image 2 of 4Sometimes it’s possible to feel the edge of the wrapped upper (Image credit: Josh Ross)Image 3 of 4Ventilation is not an issue through the upper or the insole (Image credit: Josh Ross)Image 4 of 4Like many brands, there are replaceable arch support wedges for different preferences (Image credit: Josh Ross) Verdict Shimano is a huge brand that has made excellent shoes for years. Not only do the designers have experience on their side but being able to leverage a huge database of bike fit numbers has to be helpful.

It’s also unlikely to be a bad thing to have any number of incredible WorldTour athletes wearing your shoes and giving feedback. Add it all up and it would be a huge surprise if Shimano shoes were anything less than fantastic. The brand has an obvious tailwind and I don’t think I’ll be surprising anyone by telling you that the latest Shimano S-Phyre RC903 is an amazing shoe.

Despite that, there are little details that could push you in one direction or the other. As much as I like the precision of the Shimano last, there are a lot of brands that do an even better job. Rapha, Giro, and Fizik all have a narrower midfoot and give even more of that dancing on-the-pedals feel.

If you prefer wide though, Specialized is wider still and does a better job at the top of the foot where I can sometimes feel the underlayer of the wrapped upper in Shimano shoes. It’s also worth noting that I’d rather scratch a carbon sole than rip the leather covering it. On the other hand, Shimano has some solid strengths and this latest version has taken them even further.

Specialized might be wider but the Shimano S-Phyre RC903 has more vertical volume in the toe box. These shoes also do a much better job holding my foot in place. The closest competitor is probably the Specialized S-Works Ares but Shimano has an easier cleat adjustment system, with more movement, and a lot more style.

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