Disc Brakes vs. Rim (C-Caliper) Brakes: A Complete Maintenance Guide for Both Systems

Brakes Not Working Right? Don’t Rush to Spend Money

Brakes are the most important safety system on a bicycle. If your brakes start “only stopping when you squeeze all the way to the bar” or “keep making a sharp squealing noise,” it’s time to do some work.

Adjusting C-Caliper Brakes (Rim Brakes)

Although high-end road bikes have gradually shifted to disc brakes, there are still plenty of bikes on Taiwan’s roads using C-caliper rim brakes. Adjusting them is actually quite intuitive.

Centering Adjustment

If one side of your C-caliper rubs the rim while the other doesn’t, it means the caliper isn’t centered.

1. Loosen the fixing bolt at the back of the C-caliper
2. Gently squeeze the brake lever so both brake pads touch the rim at the same time
3. While still holding the lever squeezed, tighten the fixing bolt
4. Release the brake lever and check whether the gap on both sides is even

Brake Pad Position

Cable Tension Adjustment

• Barrel Adjuster: Turning clockwise = increases the gap (brake feels looser); turning counterclockwise = decreases the gap (brake feels tighter)
• Ideal gap: about 1-2mm between the brake pad and the rim

Adjusting Disc Brakes

Disc brakes come in two types: mechanical disc brakes (cable-actuated) and hydraulic disc brakes (fluid-actuated). Most road bikes and mid-to-high-end models use hydraulic disc brakes.

Fixing Disc Rub

Does your wheel not spin freely, or do you hear a rhythmic “swish-swish” sound while riding? The rotor may be rubbing against the caliper.

Quick fix:

1. Loosen the two fixing bolts on the caliper
2. Squeeze the brake lever firmly (this lets the caliper self-center)
3. While still holding the lever squeezed, tighten the two bolts alternately
4. Release the brake lever and spin the wheel to confirm the rubbing has stopped

If it’s still rubbing, you may need to:

• Check whether the rotor is bent (use a rotor truing tool to fix it)
• Check whether the wheel is correctly and fully seated

Bleeding Hydraulic Disc Brakes

If your brake lever feels “mushy” when squeezed, as if you need to pull it all the way to the bar to get any braking power, it means there may be air in the brake line.

When you need to bleed the brakes:

• The brake lever throw has gotten longer
• Braking power has noticeably decreased
• As part of annual routine maintenance (recommended)

DIY or take it to the shop?

Bleeding requires a brand-specific tool kit and the correct brake fluid:

Using the wrong fluid will destroy the seals and ruin the entire system. If you’re not sure, it’s best to have a bike shop handle it.

Replacing Disc Brake Pads

Replacing the pads is relatively simple: pull out the retaining pin → remove the old pads → insert the new pads → reinsert the retaining pin. Just be careful not to touch the friction surface of the pads with your fingers, since oil from your skin will contaminate them.

Disc Brakes vs. C-Calipers: Maintenance Difficulty Comparison

Important Safety Reminders

• Squeeze the brakes a few times before every ride to confirm they’re working properly
• Check that your braking power is sufficient before descending
• Disc brake rotors get extremely hot — don’t touch them with your hands after a descent!
• Disc brake rotors and pads must never come into contact with oil (including the oil on your hands)
• If you can’t adjust it properly yourself, always take it to a bike shop — brakes are not something to compromise on

Related Reading

• Bicycle Brake Adjustment: Setup Techniques for Caliper Brakes and Disc Brakes
• Brake System Adjustment: The Complete Steps for Disc Brake Centering and Caliper Adjustment
• Bicycle Brake Adjustment: Gap Calibration Methods for Disc Brakes and V-Brakes
• The Complete Guide to Brake Pad Replacement and Adjustment: Covering Both Rim and Disc Brakes