The Ergo 4 features Sidi's Tecno 3 buckle system, which uses two different ratcheting dials for a customizable fit across the instep. The Tecno 3 system is low-profile and tidier than Sidi's signature ratcheting buckle, and it also allows for an even greater degree of micro adjustability and fit consistency across the entire shoe. As with all of Sidi's fastening hardware, you can fiddle with the Tecno 3 buckles in the saddle; however, the standard Tecno-3 lacks the Tecno-3 Push's little red release button. The Twelve Carbon Composite Sole is built like the road racing version of a mountaineering boot, with a carbon fiber shank running down the center to keep the shoe's power-transferring heart stiff and responsive. This is encompassed by carbon-reinforced nylon, which provides a bit of engineered flex for comfort and reduces the price compared to Sidi's all-carbon soles. The Ergo 4 also incorporates Sidi's Adjustable Heel Retention Device, which tightens the top of the heel cup to keep your foot positively planted in the shoe. The shoe's tongue and instep strap are both padded generously to allow for supreme comfort with tight buckles. Finally, all of the enclosure hardware and the heel pads are replaceable, so the shoes will outlive multiple seasons and even the occasional crash.

• Carbon-reinforced nylon sole Microfiber upper Tecno 3 buckle system Adjustable Heel Retention Device Soft Instep 3 Replaceable heel pad

Carbon-reinforced nylon sole Microfiber upper Tecno 3 buckle system Adjustable Heel Retention Device Soft Instep 3 Replaceable heel padUnknown