Review: Shimano S-Phyre XC903 XC and gravel shoes

The latest XC offering from Shimano iterates and improves on what was already a great shoe.

Caley Fretz
by Caley Fretz 23.06.2024 Photography by
Caley Fretz and courtesy Shimano
More from Caley +

The latest version of Shimano’s top-tier cross-country race shoe, the S-Phyre XC903, is more iteration than revolution, a collection of small tweaks that nonetheless have a significant impact on overall feel. That’s how it should be. It’s best not to mess with success, and the previous XC902 was already a great shoe. 

Those tweaks are almost entirely found on the upper – a better use of BOA closures, more breathability, and softer upper materials that don’t turn this onto a single-season disposable shoe, ripped to shreds by the rigours of off-road riding. The result is a shoe will fit most feet better than the previous version without giving up too much durability. The XC903 is an excellent shoe, full stop.

The short of it: A superb cross-country racing, gravel, or cyclocross shoe made even better thanks to a new softer upper and small changes to the BOA lacing.
Good stuff: More comfortable than the previous version; light at just over 310 grams per shoe; didn’t mess with traditional Shimano fit.
Bad stuff: Will wear out quicker than burlier options; expensive.
Price: US$450
Weight: 622 grams per pair actual weight for a 43.5
Sizes: 38 to 48, with half sizes between 41.5 and 46.5. 

What’s new

I posted a photo of the XC903s shortly after receiving the review pair (black size 43.5s) and the questions and concerns that came flooding in were all around fit. “Are they wider?” people asked. “Same fit as last time?” Historically you’ve either had a Shimano foot or very much didn’t, and personally, I always sat mostly in the “not” category. But despite an identical last to the previous version – the XC902 – the new XC903 fits me exceptionally well. The reasonable conclusion is that a set of design and material tweaks have broadened the range of foot shapes that will be happy inside the XC903.

So how’d they do that? With an identical last, the broad-stroke fit is theoretically unchanged, with a wide-ish forefoot and tapered toe box. But changes in upper material do produce changes in the way these shoes sit on your feet compared to previous versions. 

The biggest change is a move to the same Japanese microfiber upper that Shimano uses on the RC903, their top-of-the-line road shoe. This material is appreciably softer and more compliant than the laminated mesh found on the XC902. This new upper material wraps around the foot better, with more elasticity. The result is a fit that feels more snug, because you can ratchet down the BOAs a bit more firmly without creating hot spots. Where my forefoot would swim around a bit before, it now feels cinched down.

Softer upper material and softer BOA lace guides both contribute to a better fit.

Aiding in that result are the new BOA lace guides, which are now mesh instead of plastic. It’s a small thing, but in combination with the new microfiber it makes for a significant change in how well the uppers wrap around the foot. Everything is softer, which is good so long as it doesn’t introduce durability issues or fit slop. 

The new BOA Li2 dials have little plastic shields designed to deflect an impact around the dial itself, which is smart considering how many BOA dials I’ve popped off on a sneaky rock over the years.

The toe box has changed “dramatically,” in Shimano’s words, again entirely through changes in material. The toe outsole and toe cap mould remain the same, but the move from laminated mesh to microfiber gives those little toesies much more freedom to wiggle all the way home. 

Gone is the shark-skin-like heel material on the XC902 heel cup, which I quite liked, in favor of a smoother, leather-like heel cup cover. The “anti-twist stabilizer” on the heel cup – basically some plastic wrapped around the outside of the shoe – does a good job and I didn’t suffer any heel lift. 

Three key changes to the S-Phyre XC903 (new shoe top, old XC902 bottom):
1) No more sticky heel cup
2) BOA protectors. These are brilliant, I’ve hit them on rocks and logs numerous times already
3) Mesh BOA lace guides instead of plastic

What’s unchanged

As mentioned, the last is the same, so while the shoe may accept more feet types, it’s still roughly similar to the 902.

The toe caps and outsole remain unchanged, including the lug pattern on the bottom of the shoe. But Shimano did update the rubber used in those lugs, apparently increasing durability and lug strength. It will take another year or more of use to determine how effective that’s been. I’ll come back and update this review if the change is worth noting. 

Shimano stuck with the same carbon midsole as well, with a stiffness rating of 11. That means these are still shoes you probably don’t want to spend the day walking in. Shimano also doesn’t vary color much in its shoes. The 903XC is available in white (fastest), blue (most interesting) and black (most rational) colorways. 

Out on the trails: A ride review

Cross-country race shoes need to be light and comfortable yet durable and stiff, all while being at least somewhat walkable. Let’s be honest, we’re also talking about gravel shoes here, too, because the needs are generally pretty similar. It’s a tricky balance but the XC903s nail it. These things are great (they better be for 450 bucks). 

For context, the other XC shoes currently floating around my garage include Bontrager’s XXX MTB, Specialized’s S-Works Recon, Shimano’s RX801 gravel shoes (which is just an XC shoe with lighter lugs), and a pair of Giro Empire VR90s. Four great shoes, and the XC903 is better. 

The number one reason is shoe/pedal contact and stability. Where most shoe brands build lug patterns that will work for all manner of pedal systems, Shimano pretty much pretends those other pedal systems don’t exist. So if you run Shimano’s own SPD system, as I do, no compromises have been made for the chaos of Eggbeaters or Times. The shoe/pedal interface is rock solid. It’s as close to a road pedal feel as I’ve ever found with mountain bike shoes and pedals. 

So pedalling dynamics are superb. Fit is good, improved thanks to the softer upper, and using a last that will work for a relatively wide variety of feet. The new uppers are a revelation in terms of all-day comfort. The only shoes I have that come close are the Giro VR90s, but those suffer from lesser durability.

I like to really crank down on my shoes for racing, and stiffer uppers make it difficult to balance that locked-in feel with avoiding hotspots. Not so with these.  

My concerns when I pulled the 903s out of the box mostly centered on durability. Our trails have lots of rocks. Not smooth river rocks; sharp, decomposing granite rocks. They eat tires, shins, elbows, and yes, shoes. I had to retire an older pair of Giro VR90s because contact with one of these rocks ripped a hole in the side of the shoe large enough for my pinky toe to poke out. 

Before a cleaning. The upper material washes off well – important if you go with the white option.

My concerns were unfounded, I think. Even with the more supple microfiber material, the new uppers seem to be as durable as needed, given the intended use case. I’ve bounced my feet off a few sharp rocks and came away with scuffs or less. No holes, no rips. At least not yet. All shoes die here at some point, but nothing in the first few months of testing suggests that the useable life of these will be any shorter than other high-end models, or any shorter than the XC902s. 

Walkability is slightly below average compared to mountain bike shoes in general, but fine compared to other race-oriented options. The lugs are grippy and seem to be holding up decently well. Rubber across the arch helps in trickier scrambles. And replaceable toe spikes help if you’re going to be racing cyclocross.

I didn’t expect these to become my preferred XC shoe, based on previous experience with the road-going 902 and other Shimano footwear. My foot never quite got on with those. I always felt like my forefoot was swimming around a bit, unless I cranked the BOAs down and then I’d get hot spots elsewhere. That changed with the new uppers. The last may be exactly the same, but materials matter, and the fit on the XC903s is better (for me) than any other Shimano shoe. 

More at

Some cuts and scrapes but nothing fatal. Note these are on the inside of my foot – they’re from scrambling on foot, not riding.

What did you think of this story?