How to Adjust Mechanical Disc Brakes

Over time, your bike’s disc brakes may need a little fine-tuning to keep them working at their best. If your bike brake’s feel less responsive, are rubbing, or just need a tune-up, adjusting them can restore smooth braking and better stopping power. This step-by-step guide will show you how to adjust mechanical disc brakes on a bike - whether it’s a mountain bike, road bike, or hybrid - using just a simple hex key set.

• 1. Inspect the Brake System

  • Check the brake pads for wear. If they’re too thin (less than 1mm), replace them.
  • Ensure the rotor is clean and not warped.

• 2. Loosen the Caliper Mounting Bolts

  • Use your Allen key to slightly loosen the bolts that attach the caliper to the frame or fork.
  • This allows the caliper to move freely for alignment.

• 3. Squeeze the Brake Lever

  • Pull the brake lever firmly. This centres the caliper over the rotor.
  • While holding the lever, tighten the caliper bolts evenly.

• 4. Check Pad Alignment

  • Spin the wheel and observe the rotor passing through the caliper.
  • If you hear rubbing, the pads may not be aligned properly.

• 5. Fine-Tune Pad Position

  • Most mechanical disc brakes have a pad adjustment dial or screw:
    • Inner pad (usually fixed): Adjust using a dial or screw on the caliper body.
    • Outer pad (connected to the cable): Adjust by tightening or loosening the barrel adjuster or cable tension.

• 6. Adjust Cable Tension

  • If the brake lever feels too loose or too tight:
    • Loosen the cable anchor bolt.
    • Pull the cable slightly tighter or let it out a bit.
    • Retighten the anchor bolt.

• 7. Test the Brakes

  • Squeeze the brake lever. It should engage firmly without bottoming out.
  • Spin the wheel to ensure there’s no rubbing and the brake engages smoothly.

• 8. Final Check

  • Ensure all bolts are tight.
  • Check for rotor clearance and brake responsiveness.
  • Go for a short test ride to confirm everything feels right.

Adjusting your mechanical disc brakes at home is a quick and effective way to improve braking performance and extend the life of your pads and rotor. For a professional bike service or more advice on bike maintenance, visit your local Halfords - our expert technicians are here to help.