1. Remove the wheel. 2. Use tire levers to remove one side of the tire bead. 3. Pull out the old tube. 4. Check inside the tire for sharp objects. 5. Slightly inflate the new tube and insert it. 6. Use levers to put the tire back on. 7. Inflate to the correct pressure.
A clean chain is a fast chain. 1. Use a degreaser and brush to scrub the chain, cassette, and chainrings. 2. Rinse thoroughly with water. 3. Dry the chain completely with a rag. 4. Apply one drop of bike-specific lube to each chain link roller. 5. Let it sit for a few minutes, then wipe off all excess lube.
Before every ride, check your brakes. 1. Squeeze your brake levers; they should feel firm, not spongy, and stop well before hitting the handlebar. 2. Check your brake pads for wear; replace them if the grooves are gone. 3. Ensure pads are aligned with the rim (for rim brakes) or rotor (for disc brakes) and not rubbing.