How to Replace Your Bicycle's Disc Brake Pads in 20 Minutes

Why and When to Replace Your Disc Brake Pads

Bicycle disc brakes provide incredible stopping power, but they rely on friction material that wears down over time. Riding with worn-out pads not only ruins your braking performance, but it can also permanently damage your expensive brake rotors. You should replace your pads if the friction material (the pad compound attached to the metal backing plate) is less than 1mm thick, or if you notice a gritty, metallic scraping sound when braking.

Replacing your own disc brake pads is a straightforward mechanical task that saves you a costly trip to the bike shop. Here is how to do it in 20 minutes or less.

Gather Your Tools

Before you begin, clear a flat workspace and gather these basic tools:

• New disc brake pads (make sure they are compatible with your specific brake model, such as Shimano, SRAM, or Tektro)
• Hex keys (Allen wrenches) (typically 4mm or 5mm)
• Needle-nose pliers
• A flathead screwdriver or a plastic tire lever (used as a piston press)
• Isopropyl alcohol (90%+ ) and a clean, lint-free rag

Step 1: Remove the Wheel

Position your bicycle in a repair stand or flip it upside down so it rests securely on its saddle and handlebars. Loosen the quick-release skewer or thru-axle, and carefully slide the wheel out of the frame or fork. Critical Warning: Once the wheel is removed, do not squeeze the brake levers. Doing so will push the caliper pistons too far inward, making it very difficult to insert your new pads.

Step 2: Reset the Caliper Pistons

Before removing the old pads, you need to push the caliper pistons back into their fully retracted positions. Because your old pads are worn and thin, the pistons have self-adjusted outward. To do this safely without damaging your new pads, insert a clean, wide flathead screwdriver or a plastic tire lever directly between the old brake pads. Gently twist or pry the tool to push the pads—and the pistons behind them—outward until they are flush with the caliper body.

Step 3: Remove the Retaining Pin or Bolt

Look at the back of your brake caliper. Depending on your brake model, the pads are held in place by either a threaded pin (secured with a tiny safety clip) or a bendable split-pin (cotter pin). If you have a safety clip, slide it off with your fingers. Use your hex key to unscrew the threaded pin. If you have a split-pin, use your needle-nose pliers to straighten the bent end, then pull the pin straight out from the other side.

Step 4: Extract the Old Pads

Grasp the tabs of the old brake pads with your fingers or needle-nose pliers and pull them straight out of the caliper slot. The pads will come out together along with the metal H-shaped spring sandwiched between them. Keep these old pads nearby to compare them to your new ones and ensure you have the correct replacement size.

Step 5: Clean the Caliper and Rotor

With the pads removed, take this opportunity to clean the area. Spray your clean rag with isopropyl alcohol and thoroughly wipe down the inside of the brake caliper to remove accumulated brake dust and road grime. Next, wipe down both sides of the brake rotor on your wheel. Never touch the braking surfaces of the rotor or your new pads with bare fingers, as the natural oils from your skin can contaminate the pads and cause squeaking.

Step 6: Install the New Pads and Spring

Unpack your new brake pads and the new metal spring that came with them. Sandwich the spring between the two new pads, aligning the holes at the top of the pads with the loops on the spring. Squeeze the pads together tightly against the spring and slide the entire assembly straight into the caliper slot. You will feel them seat into place when the holes at the top of the pads align perfectly with the pin hole in the caliper body.

Step 7: Secure the Pads and Reinstall the Wheel

Slide the retaining pin or bolt back through the caliper and the pad holes. Tighten the threaded pin with your hex key (or insert a new split-pin and bend the end outward with your pliers to lock it in place). Reinstall the safety clip if your system uses one. Carefully slide your wheel back into the frame, ensuring the brake rotor slips smoothly between the two new brake pads. Tighten your quick-release or thru-axle securely.

Step 8: Pump and Bed-In Your New Brakes

Squeeze the brake lever several times. The first few pulls will feel loose, but the pistons will quickly adjust to the thickness of the new pads, restoring a firm feel to the lever. Before hitting the trails or roads, you must bed-in your new pads to transfer a layer of pad material onto the rotor. Find a safe, flat area, accelerate to a moderate speed, and apply the brakes firmly until you slow to a walking pace. Repeat this process 10 to 15 times. Do not lock up the wheels or come to a complete stop during this process, as this can cause uneven pad transfer and brake judder.