Sidi Dominator X
Sidi is a storied name in cycling shoes. Sidi modernized the cycling shoe with the first adjustable cleat, at a time when slotted cleats were nailed to the sole of a leather shoe. Nylon soles on a cycling shoe is a Sidi innovation. Sidi was the first to replace laces on cycling shoes with Velcro® closures, and later a ratcheting buckle. Importantly, the dial closure from Sidi pre-dated the Boa® closure ubiquitous on cycling shoes today.
During the mountain bike boom of the 1990s, Sidi introduced the Dominator mountain bike model in 1990, worn by none other than rising Swiss champion Thomas Frischknecht. Merlin Cycles has a nice pictorial history of Sidi cycling shoes.
Sidi Dominator 5, an Old Favorite
During the U.S. cyclocross heyday, the Sidi Dominator 5 was a shoe seen on the feet of amateurs and pros alike. Its durability in wet and muddy conditions, a slightly flexible sole, and deep spike compatibility made it a favorite.
Sidi Dominator 5
The shoe has a classic Sidi Italian fit, but is available in half sizes and a wide model. The toe box of the Dominator 5 has a narrow taper and a low volume. Many riders sized up for more toe room, but then were left with a loose heel. The Dominator 5 has Sidi’s micro-ratchet buckle to cinch the shoe in to compensate.
Sidi fans had updates to the Dominator series with the Dominator 7 and then the Dominator 10, the latter improved with Sidi dial closure.
Sidi Dominator 10
New Sidi Dominator X
The Sidi Dominator X
Sidi has the new Dominator X made on a new last with a slightly wider, and certainly taller, roomier toe box. We asked for a pair to review and Sidi sent us a white colored pair. They certainly are flashy, and given the popularity of white shoes among roadies, they look racy. The overall look is a departure from the old Sidi, but still different than other shoes out there. It maintains a somewhat unique Sidi style.
I’ve worn Sidi shoes in the past, always with the same fit and feel. The new Dominator X is certainly different. The toe box is certainly taller and fits wider, even if it doesn’t look wider side by side with an old Sidi shoe. I tried on the shoes at the 2026 Sea Otter Classic and found I could go a full size smaller than previously with Sidi.
The new Sidi Dominator X next to a 20-year-old Sidi shoe.
The one-piece upper is stiffer, and the material feels a bit more plastic-like. It has a mesh texture, but is not a mesh. Perhaps it improves the shoe’s aerodynamics by acting as a turbulator. There are ventilation perforations. The lightly padded tongue is sewn on one side so it does not decenter.
The size 44 sample we have weighs 430 grams per shoe out of the box, or 860 grams per pair. Not the lightest XC shoes out there.
Bottoms Up
The Dominator X sole is considerably stiffer than previous versions of the Dominator series. Thankfully, Sidi thoughtfully put tread material under the arch area for pedal traction in the case of a fast remount without hitting pedal engagement perfectly!
The Sidi Dominator X has a stiff sole and deep lugs
Sidi lug material is notoriously hard and sometimes slippery. The lugs are still hard and a bit slippery, but they are deeper. I measured the old Dominator and Trace sole lugs at 6mm deep around the cleat. The new Dominator X is 7.5mm deep. That has a couple of advantages. The lugs contact the pedal outside the cleat area, giving more pedal stability. The deep lugs dig in for good traction on a hike-a-bike section. The disadvantage is the need to shim the cleats for pedal engagement.
I mounted the cleats without a spacer and could not engage the shoe solidly to the pedal. I added a 1mm spacer under the cleat and achieved a solid connection with some initial effort to “snap in”, particularly with pedals that have a more solid engagement. Pedals that had a wobbly engagement now felt solid. I prefer a more solid engagement, but there will be more effort to engage in conditions with muddy shoes and pedals.
Dialed In
Sidi put dials on cycling shoes before any other company in my recollection. According to some sources, Sidi shoe dial closures pre-dated Boa® dials on cycling shoes. Regardless, the Sidi dial closure operates differently. Each dial has a flip-out lever to assist with tightening. A button on the side of each dial releases the tension. The dials tighten clockwise, regardless of which shoe. Boa® and Uturn® (on the Quoc shoes) tighten clockwise on the right shoe and counterclockwise on the left shoe, giving the system a mirror-image symmetry. A small detail.
Old Sidi dials tightened monofilament nylon. Boa uses multi-strand small-gauge insulated wire. The new Sidi dials use Dyneema cord, more flexible with more strength. In my experience, the Sidi dial system with Dyneema cord is the smoothest, with less tangling and easier release.
The Sidi NUUN dial. Flip the lever out, tighten clockwise. Push the button to release tension.
Dominantly Stiff: Upper and Lower
Sidi has a sole stiffness rating of 8/10. Of course it is relative, and I wonder what a 10/10 feels like. Recent studies show little in the relationship between cycling shoe sole stiffness and power transfer. The sole of this Sidi Dominator X is subjectively stiff, both when flexing the shoe while clamped to a bench, and when pedaling hard uphill in a big gear. It certainly flexes less than the Quoc Touring 2, which reminds me of the old Sidi Dominator’s nylon sole. I like the Dominator X’s sole stiffness-with the right insole, it feels efficient but not so stiff that my feet become numb on a long hot ride.
Hike-a-bike sections, or running sections of a cyclocross race, feel less natural with the stiff sole of the Dominator X compared to the more flexible Dominator 5. Cinch the shoe tight to avoid heel lift.
The Dominator X one-piece upper is also stiff, certainly not as flaccid or leather-like as the stitched-together Lorica upper of age-old Sidis. If it presses on a specific part of your foot and causes discomfort, it will not improve because the upper material does not stretch or break in to conform to your foot. Adjusting the shoe with the dials will help. I wore the shoes for over 1000 miles in all conditions. On a particularly hot day, my foot swelled, causing a pressure point along the side of the shoe. Loosening the shoe helped, but then my foot had some heel lift due to the stiff sole.
I’m not against a stiff upper, and the new Sidi last suits me. I like a stiff upper more than a flaccid one. I also expect good durability with the lack of seams.
Italian Style
Sidi sent me the Dominator X in white, and I receive comments about white shoes for off-road all the time. White shoes are fashionable for road shoes, and this pair with black accents and orange dials looks flashy. I like the attention it brings. I like looking down at the racy Italian style and now find myself selecting socks to match my kit. The shoes have gone through dust, mud, and sand. Certainly, they display the terrain, but with a light spray of soapy water and a rag, they look as good as new. The textured surface sometimes needs a light scrub with a brush, but making the shoes look clean and new is not a problem. Darker scuffs from rubbing an aluminum crank are more difficult, but a bit of mild solvent or polish will clean them up.
If white is too flashy, or too “high maintenance,” you can get the Dominator X in classic black, sand (tan), or forest green (with white accents).
Parts and the Right to Repair
Historically, Sidi shoe small parts are available. This includes straps, buckles, dials, cords, shoe tread sections, and spikes. The new Dominator X is no different. If you break a dial, cut a cord, or the strap breaks, the replacement part is available. The Dominator X does not have replaceable sole tread, however.
The Verdict
Shoes are a personal item important to the enthusiast’s cycling experience. Most importantly, the shoe has to fit well. The new Dominator X is a great shoe for gravel racing, cyclocross, or mixed-terrain performance riding. Sidi fans will find the fit and dials familiar, but you should try the shoe on at your dealer since the last is different. If you haven’t tried Sidi shoes in a while, perhaps this is one to consider.
The new Dominator X is not a lightweight but has proven durable so far and has replacement parts available. They are attractive, easy to maintain, and have features I like for a race-oriented off-road shoe. They’re not inexpensive, but Sidi has an extensive lineup of gravel-oriented shoes if you like the brand.
Sidi Dominator X Specs:
USD 370
860 grams per pair, size 44 sample
European Sizes 36-48 with ½ sizes between 37 -47
More info: sidi.com
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