At just 175 grams, the Giro Empire SLX shoes are breathing some pretty rarefied air. Not many shoes on the market come within 100 grams of the Empire, but it's not giving up anything in terms of performance, either. The uppers are a single piece of Evofiber microfiber, which is highly breathable, but is also perforated for additional airflow. The shoe closes using just the laces you no doubt noticed, but those laces are specially designed to remain tied, and there's also a lace garage on the tongue to ensure they don't get anywhere near your drivetrain. Those uppers are attached to an ultra stiff Easton EC90 SLX2 Carbon Sole. This sole is among the stiffest available, and due to high grade of carbon fiber used in its construction, is also one of the slimmest, producing a stack height of just 6. 5mm. A low stack height means less power lost to thick cleat plates. And, to make the Empire SLX even lighter, Giro's opted for another old school classic Ti hardware. Between the uppers and the sole sits Giro's lauded SuperNatural FitKit, the long name for its user tunable footbed. These insoles have swappable arch support so you can tune the fit of your shoes precisely to your feet.