Tech Tip of the Week: Quieting Shimano Brake Pad Rattle

How to quiet Shimano brake pad rattle
Shimano Finned Brake Pads (XT M8120 Brakes)

Intro

Heat dissipation is one of the biggest challenges in mountain bike brakes, and companies have tried all manner of techniques to keep it in check. Shimano have had some of the more creative ideas out there — from their dual-material Ice Tech rotors, to adding cooling fins to their brake pads.

It’s those fins that are the subject of this week’s tech tip — plenty of riders and several Blister reviewers have noted that the added weight of the fins makes the pads prone to rattling and making noise on the trail. It’s annoying, especially for the more noise-obsessive folks out there, but fortunately there’s also a relatively easy fix.

Tech Tip of the Week: Quieting Shimano Brake Pad Rattle, BLISTER

Quieting Shimano Finned Brake Pads

The trick to quieting the dreaded brake pad rattle is to add a little rubber mastic tape along the top edge of the brake caliper, underneath the bottom edge of the pad fins. I use 3M 2228 tape — a must-have for quieting all sorts of noise on bikes, including chain slap and cable rattle — and it works very well here, too. It’s easy to apply, and you can do a pair of brakes in less than 5 minutes.

Here are the basic steps:

(1) Remove the brake pads by prying off the small clip on the back side of the pad retaining bolt, and then unscrewing the bolt from the caliper. There’s no need to take the caliper off the bike or remove the wheel.

How to quiet Shimano brake pad rattle
Shimano Finned Brake Pads (XT M8120 Brakes)
How to quiet Shimano brake pad rattle
Shimano XT M8120 Brake (pads removed)
(2) Thoroughly clean the top of the caliper with a clean rag and isopropyl alcohol. It’ll be covered with a mix of dirt and brake pad dust, and you’ll want to get that off so that the tape can properly adhere.
How to quiet Shimano brake pad rattle
Shimano XT M8120 Brake (pads removed, caliper cleaned)

(3) Cut two strips of tape approximately 4.5 x 40 mm (roughly 3/16’’ x 1.5’’) and stick them to the caliper along the top edges of the brake pad opening, right underneath where the edge of the pad fins would sit. Smooth the tape over the bump for the brake pad fixing bolt, and make sure it’s not overhanging into the brake pad opening.

[Note: dimensions above are for a 4-piston caliper; the 2-piston versions likely require a slightly shorter strip of tape, but I don’t have one handy to measure.]

How to quiet Shimano brake pad rattle
Shimano XT M8120 Brake (tape applied)

(4) While you’re at it, bend the brake pad return spring slightly wider with your fingers so that it exerts some extra force to hold the pads against the caliper, then re-install the pads, spring, retaining bolt and security clip.

How to quiet Shimano brake pad rattle
Shimano XT M8120 Brake (tape applied, pads re-installed)

(5) Repeat the process for the other caliper, and go ride.

This technique might not eliminate every single bit of pad rattle, but it goes a long way and it’s cheap and easy to try if you’re finding yourself annoyed by the noise. It is also worth noting that the mastic tape does tend to get stuck to the brake pads and will likely get pulled off when you replace them. Just plan on replacing it when the time comes for new pads. And as always, let us know how this one works for you in the comments.

3 comments on “Tech Tip of the Week: Quieting Shimano Brake Pad Rattle”

  1. Awesome sauce. Both the mastic and “overbending” of the spring work well. I’ve also had good luck in a pinch with self-adhesive velcro.

    However, the best solution to pad rattle is non-finned MTX brake pads. Great stuff, and actually currently available for purchase!

  2. Thinly coat “CRC DiscBrake Quiet” (auto-parts store) on outboard side of pad frame (minus piston contact area), let dry.

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