Sidi bicycle shoes are made specially to survive rougher conditions cyclists may encounter. In addition to the rigid sole common to other types of bike shoes, Sidi shoes feature special clasping mechanisms to make the shoe fit more tightly against the wearer's foot. This tighter grip helps to ensure that the shoe will not come off during a difficult ride, and enhances the power transfer to the bike's pedals by reducing movement within the rider's shoe. Sidi features four main clasping mechanisms, each manipulated in a different way for removal.
Lift both sides of a Calliper buckle simultaneously. The two tabs on either side of the buckle are the only two moving parts on the buckle itself when the shoe is fastened, so they are easy to spot. When you lift the tabs, the serrated strap will free from the buckle, allowing you to loosen the shoe enough to remove it.
Push on both red tabs on an Ultra SL buckle. This will release the serrated strap, allowing you to loosen the shoe enough to remove it.
Press the unlocking button down while lifting the semi-circular handle on the clasp of a Techno II buckle. Turn the handle clockwise while wiggling your foot to loosen the clasp. When the shoe is sufficiently loose, slide your foot out.
Grasp the top strap of a High-Security Velcro clasp and pull the two straps apart firmly.