Assess the Problem and Identify Your Brakes

Before you touch any bolts, figure out what needs fixing. Squeeze your brake levers. Do they feel too soft and pull all the way to the handlebar? This suggests the cable is too loose or the pads are worn. Do they feel too tight and engage with only a tiny pull? The cable is likely too tight. Spin the wheel. Can you hear a persistent rubbing or scraping sound? This means the brake is misaligned and dragging.

Next, identify the system you're working with:

• Rim Brakes: These have pads that press against the wheel's rim. Common types are V-brakes (two long, separate arms) and calliper brakes (a single U-shaped mechanism mounted above the wheel).
• Disc Brakes: These use a calliper that squeezes pads onto a metal rotor mounted to the wheel's hub. They can be mechanical (operated by a steel cable) or hydraulic (operated by fluid in a hose). You can tell them apart by looking for a thick, sealed hose (hydraulic) versus a thinner, flexible metal cable (mechanical).

Clean All Braking Surfaces

A clean brake is an effective brake. Dirt, oil, and old rubber residue can severely reduce your stopping power and cause annoying squealing. This step is essential and often solves braking issues on its own.

For rim brakes, use a clean rag with a bike-specific degreaser or isopropyl alcohol to wipe down both sides of the wheel rim where the pads make contact. Use a small pick or screwdriver to carefully scrape out any embedded metal shards from the brake pads themselves.

For disc brakes, use a clean rag and isopropyl alcohol to wipe down the rotor. Never use bike degreasers or lubricants like GT85 or WD-40 on a brake rotor, as they will contaminate the pads and ruin them. Avoid touching the rotor with your bare hands, as oils from your skin can also cause contamination.

Adjust Cable Tension for Correct Lever Feel

This step primarily applies to rim brakes and mechanical disc brakes. The goal is to have the brake lever engage firmly about halfway through its pull. If it pulls too far or not far enough, you need to adjust the cable tension.

For minor adjustments: Locate the barrel adjuster. This is a small, round knob where the brake cable enters the brake lever or the brake calliper. To tighten the cable (making the brakes engage sooner), turn the barrel adjuster anti-clockwise. To loosen it, turn it clockwise.

For major adjustments: If the barrel adjuster doesn't provide enough range, you'll need to reset the cable at the pinch bolt. First, turn the barrel adjuster all the way clockwise (in). Then, locate the pinch bolt on the brake arm or calliper that clamps the cable. Use an Allen key to loosen this bolt just enough so the cable can slide. Squeeze the brake pads against the rim or rotor with your hand. With your other hand, use pliers to pull the cable taut, removing any slack, and then re-tighten the pinch bolt securely. Now, use the barrel adjuster for fine-tuning.

Align and Position the Brake Pads

Properly aligned pads ensure maximum contact with the braking surface for better power and even wear. Worn or misaligned pads are a common cause of poor performance.

For rim brakes, loosen the bolt that holds the brake pad. Position the pad so it sits flat against the centre of the rim's braking track. It should not touch the tyre (which can cause a blowout) or hang below the rim. A slight "toe-in" can prevent squealing: angle the front edge of the pad to touch the rim slightly before the rear edge. A gap of about a credit card's thickness at the rear of the pad is a good starting point. Hold the pad firmly in this position and tighten the bolt.

For disc brakes, pad alignment is mainly about checking for wear. Inspect the pads inside the calliper. Most have a wear indicator line. If the braking material is less than 1mm thick, it's time to replace them. Replacing pads is a separate job, but checking them is a key part of any adjustment.

Centre the Brakes to Prevent Rubbing

If the wheel spins freely but the brakes rub, they need to be centred. This ensures both pads contact the braking surface at the same time and sit an equal distance away when at rest.

For V-brakes, look for small screws on the side of each brake arm. Turning a screw clockwise will increase the spring tension on that side, pushing the arm away from the rim. Turning it anti-clockwise will decrease tension, allowing it to move closer. Adjust these screws in small increments until both pads are equidistant from the rim.

For mechanical and hydraulic disc brakes, the process is usually simpler. Slightly loosen the two main bolts that mount the brake calliper to the frame or fork. Don't make them fully loose, just enough for the calliper to wiggle. Squeeze and hold the corresponding brake lever firmly. This action will automatically centre the calliper over the rotor. While still holding the lever, carefully and alternately tighten the two mounting bolts. Release the lever and spin the wheel. The rubbing should be gone.

Address Hydraulic Disc Brake Specifics

Hydraulic brakes self-adjust for pad wear, so you don't need to manage cable tension. However, they can develop their own unique issues. The most common is a "spongy" or "mushy" lever feel, which indicates air has entered the sealed fluid system.

Fixing this requires a "brake bleed," where you flush the old fluid and any air bubbles out, replacing it with fresh fluid. This is an advanced task that requires a specific bleed kit for your brake brand (e.g., Shimano, SRAM, Tektro) and some patience. If your levers feel spongy and pumping them a few times makes them feel firmer temporarily, it's a sure sign a bleed is needed. While a full bleed guide is beyond this article's scope, identifying the need for one is a key diagnostic step.

Another issue can be a "sticky" piston that doesn't retract properly, causing pad rub. You can sometimes fix this by removing the pads and carefully cleaning the sides of the pistons with a cotton bud and isopropyl alcohol.

Check and True a Bent Disc Rotor

If your disc brake rubs in a specific spot rather than continuously, you may have a bent rotor. Watch the rotor as you spin the wheel slowly. Look at the gap between the rotor and the brake pads. If you see the rotor "wobble" and touch a pad at one point in its rotation, it needs truing.

You can make small adjustments using a dedicated rotor truing tool (or a clean adjustable spanner in a pinch). Identify the bent section. If it's bent towards the left, place the tool on the right side of the rotor and gently bend it back towards the centre. Make very small, incremental adjustments. It’s easy to overdo it. Spin the wheel and check after each adjustment until the wobble is gone.

Final Check and Safe Test Ride

Once you believe everything is adjusted correctly, perform a final safety inspection. Go around the bike and check that every bolt you touched is fully tightened. This includes brake pad bolts, cable pinch bolts, and calliper mounting bolts. A loose bolt here can have serious consequences.

Lift the wheel off the ground and spin it. It should rotate freely for several seconds without any rubbing sounds. Squeeze the brake levers. They should feel firm and responsive, stopping the wheel promptly. Now, perform a careful test ride in a safe, flat area away from traffic. Start slowly and test both front and rear brakes individually. Listen for any strange noises and feel how the bike responds. Once you are confident they are working correctly, you are ready to ride.