A sidewall cut 40 miles from home turns a ride into a walk in a hurry. You can improvise with a dollar bill or a gel wrapper, but neither sticks to the inside of the tire, and both tend to shift around when you remount and inflate. Park Tool's TB-2 Emergency Tire Boot solves that problem with a dedicated adhesive patch that stays where you put it. Each boot is constructed from a waterproof vinyl membrane with fiber weave reinforcement, and the pressure-sensitive adhesive bonds directly to the inside of the tire casing so the boot holds its position while you reinstall the tire and tube.

To use the TB-2, you peel the protective backing off the boot and press it firmly onto the inside of the tire casing, centered over the cut or damaged area. The adhesive grips on contact, and once the tube is inflated it pushes the boot against the casing wall, reinforcing the bond with air pressure. The boot itself is thin enough that it doesn't create a noticeable bump as the wheel rotates, which matters when you're riding the remaining miles home on a repaired tire. Each boot measures approximately 76mm x 45mm, which is large enough to cover a significant sidewall gash or tread cut. You can also trim them down with scissors if you're working with a narrower road tire and want a cleaner fit inside the casing.

The 3-pack fits easily in a saddle bag, jersey pocket, or frame bag alongside your tube and levers. One boot handles one incident, so carrying 3 gives you coverage for a full season of rides in most cases. Keep in mind that the TB-2 is designed for tubed tire setups and is not intended for tubeless systems — the adhesive needs a clean, dry surface to bond properly, and residual sealant inside a tubeless tire can compromise adhesion. Park Tool also notes that any booted tire should be considered a temporary fix, and the tire itself should be replaced as soon as you get home.