Sidi Dominator X review: Lightweight cross-country mountain bike shoes tested

The Sidi Dominator X offers precise fit adjustment through dual rotary ratchets, balancing stiffness and comfort in a durable XC race shoe.

Cross-country gear is so hot right now. Literally, it’s getting hot on Earth’s northern half, and lightweight XC gear is ideal for summer fun. Sidi’s Dominator X sits at the center of the Italian brand’s shoe lineup, with differences in weight, stiffness, and adjustability setting each XC race model apart.

Dominator X women’s pairs come in two colors and are available in sizes 36-43, while the men’s are available in four hues with sizes running between 36 and 48.


Sidi Dominator X key specs

  • Ratchet-style closure system
  • Carbon composite outsole
  • Price: $370
  • Buy from Backcountry (20% off with a free Backcountry account through June 8, 2026)

Looking from the rider’s-eye-view, Sidi has designed a proprietary rotary ratchet to tighten the Dominator X laces. They did a fine job with the details. The ratchet feels solid, with tight detents for microadjustments. The upper ratchet has a secondary adjustment on its strap for further fit fiddling. Unlike other adjustment ratchets I’ve used, this one doesn’t bind or become difficult to reopen if you like to wrench it down extra tight. Simply press the release, and it follows suit.

Alt text: A pair of worn cycling shoes with cleats on a wooden surface, showcasing a predominantly white design with black and neon yellow accents. The soles are dirty, indicating recent use.

The carbon composite outsole has a stiffness index of 8 on a 1-12 scale. In addition to the heel and toe lugs, there is a mid-foot lug to catch the pedal in case you miss the mark while clipping in. There are bolts under the toes that can be swapped with spikes for cyclocross racing, or whatever DIY traction setup you decide to bolt on your shoes. Finally, the outsole has a long cleat track that should please most riders. I typically run my cleats toward the rear, but this track is long enough that I mounted cleats toward the middle to achieve my usual pedal placement.

Race shoe stiffness can have its limits, depending on your feet. I have ridden carbon-soled shoes that are so stiff that my feet cramped during rides. Stiffer isn’t always better. The Dominator X sole strikes a healthy balance in the flex department. I can’t feel my cleat or pedal, and there’s no noticeable give when you stand up and stomp the throttle. The shoe feels plenty stiff for energy transfer while allowing enough movement to keep sensitive feet like mine from whining.

Close-up of a pair of hiking shoes resting on a moss-covered log. The shoes feature a white and gray design with black accents and bright green laces. The outdoor setting suggests a connection to nature and adventure.

It’s great to see XC shoes with bolt holes under the toes for extra mud spikes. That little detail can make all the difference in a slippery XC or CX event. The rubber tread cleats across the bottom of these shoes are slightly stickier than those of some competitors. If you need to stop on a rock slab to take a look at a feature, the Dominator X will stick on a lower angle. Most folks likely ride rock slabs in flexible, soft shoes, but if you prefer XC slipers all the time, then you know how important the tread grip can be. Just don’t step directly on the cleat.

A close-up view of the back of two athletic shoes resting on a moss-covered wooden surface, with a blurred green background. The shoes feature a mix of black and white materials and have detailing on the heel.

The light colored upper is quite tough. I like to remember where my chainstays are with each pedal stroke, and the Dominator X inner heel feels solid enough to take a few years of that friction. Construction throughout is tight and clean, with no seams loosening or fraying during my testing.

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Tough shoes are rarely breathable, and these are no exception. They breathe enough for my needs, but riders with sweaty feet might look to Sidi’s featherweight options for additional wind. I’ve pedaled through a few 80° F (27° C) days without thinking about how warm my feet are, so it’s likely these are plenty vented for most.

Fit is one element where I struggled with these shoes. Sidi did everything possible to make these shoes adjustable, but my narrow feet were swimming in my usual size 44. Switching to a size 43 had my toes rubbing the toebox. I put the 44 back on and added an insole to take up the slack. From then on, they fit great, if a tad long. Likely 43.5 would be the Goldilocks here, and either way I would recommend trying before buying if you are able. If not, consider ordering a half size smaller than your usual.

A pair of worn cycling shoes with a sleek design, featuring a predominantly white exterior and black accents. The shoes have a dirtied appearance, highlighting their use, and are secured with a closure system that includes visible laces and clips. They are positioned on a moss-covered wooden surface, with greenery in the background.

Pros and cons of Sidi Dominator X

Pros

  • Lightweight
  • Stiff
  • Sturdy material

Cons

  • Expensive
  • Fits larger than expected

Bottom line

The Sidi Dominator X is for someone who wants a dialed fit adjustment in their shoes. The rotary ratchets allow precise squeezing exactly where you like it, and they are easy to actuate on the fly. For the price, these shoes will need to last a while, and fortunately, it seems Sidi considered durability throughout.