Pearl Izumi X Project Shoe Launch


In the words of Pearl Izumi, the magic of the shoe is the sole! Their goal for the sole of the shoe was flexibility in the toe section for hiking up steep slopes, and lateral stiffness under the pedal interface for power transfer, with torsional flexibility and pliability in the rear portion for nice purchase on uneven terrain.
To come up with the ideal sole, they did extensive VO2 and power transfer testing at CSU’s Physical Activity Energetics/Mechanics Lab (PAL) under Dr. Ray Browning over a year-long process, testing and removing material from the sole to see how performance changed. They cross compared these parameters against their own race shoes and the competitions so that they had a good barometer of things.

A very important aspect of the sole was their partnership with Italian shoe and composite manufacturers, whom have expertise in carbon fiber, co-molding, TPU and lugs. The craftsmanship and knowledge base of the Italian artisans are beyond reproach, and no one else in the world can match their shoe wizardly and understanding.

They went through many iterations of the sole’s carbon plate size and length and shape to get optimal stiffness with as little material as required, and it turned out that the rear and toe portion didn’t need as much as under the pedal interface. After finding where material was needed longitudinally, they started on the layering geometry of the carbon plate. There is lots of tuned layering with unidirectional as well as woven carbon fiber under the pedal interface, and then tapered construction as you move away from pedal area into a sheet carbon and TPU under the heel and forefoot. It’s very complex how the tapering happens between the layers from one end to the other, especially since abrupt or sharp transitions would cause issues, such as weak spots, so it needs to be done gradually. The front of the shoes has more layers than the rear, while the pedal interface has the greatest amount.

The 1.0 and 2.0 uses the same carbon fiber construction on the sole, while the 3.0 uses more of a glass fiber layup, although the end performance characteristics are the same for all models.

Instead of using TPU lugs for the rubber tips, which have a poor grip, they decided to go with a system which is more commonly used on high end Italian mountaineering boots. Many mountain bike race and high end performance shoes tend to slip around on rocky surfaces and roots, and you feel like your “Skating Away on the Thin Ice of a New Day.”  The X Project uses co-molded and injected carbon rubber tips, which have excellent durability and grip, and no delaminating or peeling issues. Under the lugs, as much material as possible is cored out of the TPU frame to save weight, without degrading performance, strength and durability. They use an EVA foam in the heel, which has been co-molded, and offers a good job of absorbing impact and distributing it across the heel instead of up into the body.

First Impressions
At the press camp, Brian Lopes took us out on some uber steep dirt hike-a-bike trails, so we got a great idea of how the X Project 1.0 shoe felt while walking. The toe section had a nice flex up towards the end, though they didn’t feel as flexible during hiking as their Alp-X Elite shoes. I did like the pliability in the rear, as it made the shoe conform to the trail’s slope, which was especially evident when side stepping. I did notice a slight amount of heel lift, though it seems to have lessened with a break-in period over the last week or so during my post press camp usage. When pedaling, the shoe had excellent power transfer, and felt as stiff as any race shoe I have used. When you’re on the pedals, I didn’t notice the slight flex in the rear of the shoe, or else it just blended into the comfort and usability. The toe box is snug, but it wasn’t narrow enough to cause any pinching or discomfort issues, though after a long day in the saddle with swelled up feet it might become an issue? I really liked the P.R.O buckle system, which had a nice release button and an easy to use lever adjuster, which made on the fly tuning extremely simple.

Overall, I was mighty impressed with the shoe, as it let me get off the bike and hike around with comfort and safety, and still gave me impressive power to the pedals. It was comfortable, had a semi-custom insole, an excellent buckle system, grippy lugs, and was a good for hiking and excellent for pedaling. If you do extensive hiking, you’ll want their X-Alp series shoes, but you’ll lose the power transfer characteristics of the X Project.


  • Excellent power transfer
  • Good hiker
  • Comfortable
  • Light – 320 grams
  • Semi-custom insole
  • Grippy lugs
  • Excellent buckle on 1.0


  • Heel lift
  • Width is slightly narrow
  • Not a pure hike-a-bike shoe – look to the X-Alp series
  • Expensive

About the author: Brian Mullin

Brian likes to push the limits in all the sports he obsesses in, whether it's mountain biking, whitewater kayaking, skiing, or sport climbing. He takes those same strengths and a good dose of insanity to his reviewing and writing on mountain biking products, creating technical, in-depth articles. Whenever he's not on the bike, he might be found watching MotoGP racing, otherwise look for him out on the trail.

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  • spokes572 says:

    why so bright colors. No gray or black. Biking is not a Rumba class.

  • Francis says:

    >>why so bright colors. No gray or black. Biking is not a Rumba class.

    Agreed. All of the models need to be available in grey or clear accent. Some neutral color. Currently, the X Project 1 is only available in green, the 2 in orange and the 3 in red. This will force some buyers to go up and down the product line depending on color preference.

  • Warp says:

    So, basically the main difference is the buckle and inserts? Weight difference is 10grs from top to bottom model, so not a factor or one easily lost on manufacturing tolerances.

    Hard to gulp the extra 120 bucks for the top of the line just for inserts and buckle… unless you REALLY like neon green. If you only need the inserts you can just shell out the extra 50 bucks for the middle one… if you really like orange.

    The top of the line will be a hard sale given the little difference with the lesser models and the higher price. But what do I know? XTR sells like pancakes.

    • Brian Mullin says:

      Each of the three models uses different materials for the uppers, which is detailed in the article. I am not sure of the exact weights between the models, since they are not in production yet, so take them with a grain of salt. The 1.0 upper has better ventilation and is more supple, while the 2.0 uses synthetic leather and would best suit UK wet climes, while the 3.0 use synthetic leather and mesh. They all have the same performance from the sole and sticky lugs, and the 3.0 just uses a heavier glass layup instead of full carbon fiber.

  • Steve says:

    No wide sizes, booooooo

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