Shimano’s 2012 R315 road shoes aren’t exactly custom, but once they’ve been properly fitted, no two pairs are exactly alike. That’s because the fit process involves baking the heat-moldable shoes and insoles in a special oven and vacuum-fitting them to the wearer’s feet. I was recently set up with a pair for this week’s Wired Bike Test.

The ski and snowboard industry has been using heat-moldable insoles in boots for about 20 years. Shimano was the first company to bring the concept to the cycling industry, in 2007, and now offers it in several models. The $379 R315 is the company’s top-end race shoe, with a stiff carbon-fiber sole and synthetic uppers.

As with ski boots, the idea here is to provide added comfort inside the rather unforgivingly stiff footwear while also keeping the foot in place better, which improves performance.

My 15-minute fit process began with a technician placing my insoles in a small oven heated to 210 degrees. (Shimano dealers have the ovens in their shops.) A minute later, I put the insoles back in the shoes, strapped them on, and wore them for five minutes, until the insoles had cooled and settled in the shape of my foot.

Next came the shoes. The heat-moldable material is built into the uppers at key spots like the toe box, the tongue, and the heel cup. We baked the shoes one at a time, minus the insoles. After three minutes, my fitter would remove the shoe from the oven, replace the insole, and quickly strap the shoe to my foot. He would then place a thick bootie over my foot, fire up the vacuum, and wait.

As the air rushed out, the bag and, thus, the shoe, squeezed tightly against my foot and held it there as it cooled. I was warned that this step of the process might be uncomfortable, but it was kind of awesome. Give it a fancier name and it could be a spa treatment.

After the shoes had cooled, there were visible changes. The insoles and heat-moldable sections of the uppers had dents and bulges where they had formed to my foot, and the heel cups pinched more tightly around my Achilles tendons.

I’ve already started riding the shoes and will really put them through their paces this week at the Wired Bike Test. Check back later for a full review.