Road bike disc brakes: eliminate squeaking and noise
Check screws
First: Check all screw connections on the brake calliper and disc. Loose parts can cause vibrations that are transmitted to other areas.
Cleaning brake pads and discs on racing bike disc brakes
The most common cause of disc squeal is dirty pads or water on the brake disc; this usually also reduces the braking force. If water is the cause, the noise usually disappears after heavy braking and the braking force returns to normal. However, oily pads or pads contaminated with other chemicals can usually no longer be saved - you must then fit new pads and be sure to clean the disc with brake cleaner.
Check the installation of the disc brake
If the brake calliper sits slightly tilted on the fork or frame, the pads do not hit the disc flat and can squeal as a result. This can be caused by paint residue at the mounting points. You can carefully scrape off the paint or ask a dealer to mill the screw mountings flat using a special tool.
Parts tip against squealing road bike disc brakes: SwissStop Silencer
If the disc only squeaks at low speeds, this is often caused by the so-called slip-stick effect: the pads adhere to the disc for a short time and then come loose again, causing the vibrations. The squealing often disappears after a braking phase - if not, the Disc Silencer from SwissStop can actually help. It reduces the braking force only slightly, but reliably prevents squeaking.
Road bike disc brake grinds: The best tips
Readjusting the brake calliper
If the road bike brake only grinds after heavy braking, the parts will warp under load. Readjust the brake calliper and tighten the bolts to the specified torque. In the case of wheels with quick-release axles, the wheel can also shift in the dropouts: Experience shows that only sturdy quick-releases with a high clamping force can withstand the loads. Do not use lightweight components!
Straightening the brake disc on the bike
Ice-Tech discs from Shimano can grind slightly after heavy braking because they warp slightly due to the heat. However, the grinding should disappear again after a short time. If the disc is bent, it must be centred. If necessary, this can be done by hand: simply press gently in the desired direction. It is more precise with a slotted centring tool, which gives you a better grip on the disc and a larger lever.
Cleaning brake pistons on racing bike disc brakes
If one of the pistons in the caliper of the disc brake does not move back completely, it will grind permanently on the disc. It then helps to clean and mobilise the pistons.
Tool tip against grinding road bike disc brakes: Hayes Feel'R Gage
The tool from Hayes makes adjusting the brake calliper easier: position it on the disc, slide it into the calliper and pads and tighten - the thin stainless steel plates ensure the distance and parallel alignment of the pads. Price 20 euros.
Parts tip against grinding road bike brake discs: Syntace Disc Shims
If you ride several wheelsets, you usually have to adjust the brakes as well as the gears when changing them. For discs with six-hole mountings, washers can help; these allow the brake discs to be positioned with an accuracy of two tenths of a millimetre. For example from Syntace - eight pieces for 9.90 euros.
Adjusting the brake calliper
If the brake calliper is not centred over the disc or is not parallel, the pressure point will be spongy: When braking, the disc is first bent slightly before the brake grips properly. Adjust the brake precisely first, you can find detailed instructions for the screwdriver in the video here:
Check brake pistons
If one of the two pistons is stuck in the brake calliper, the brake is only working on one side and the pressure point is not clean. Dirt is usually the cause; first clean the brake calliper thoroughly from the inside with the pads removed using cleaner and water. Press the pistons out slightly with the brake lever, drizzle the sides with a little brake fluid and then carefully press them back into the housing using a special spacer or a piece of wood. Then readjust the brake.
Road bike disc brakes: Air in the system
If the pressure point remains soft or comes too late, there is probably an air bubble in the system. Then you need to bleed the road bike disc brake system. A bleeding set costs around 15 euros and the procedure is not rocket science. We show you how it's done in the DIY video here:
Pressure point adjustment for Campagnolo brakes
Hydraulic disc brakes from Campagnolo have the special feature that - in addition to the grip width - the free travel to the pressure point can also be adjusted in two positions. Access to the screw is located on the inside of the lever body. Turn in the "S" direction for shorter free travel and in the "L" direction for longer free travel.
Tip for mechanical disc brakes on a road or gravel bike
With mechanical disc brakes that work with classic Bowden cables, the pressure point and modulation depend heavily on the cables and cable housings. Special pressure-resistant sleeves noticeably improve the pressure point. Jagwire cable housings, model KEB-SL, have proven their worth.
Jens Klötzer
Editor
