Pads for Shimano GRX BR-RX400 disk brakes

Mr Purple
Posts: 2876
Joined: Sat Sep 12, 2020 1:14 pm

Re: Pads for Shimano GRX BR-RX400 disk brakes

Postby Mr Purple » Fri Feb 23, 2024 12:53 pm

Yeah, I'm leaning that way. The only thing holding me back is I'm not sure I can actually replace the pads without messing it up. So I'll check Youtube and if I'm not sure just get the whole thing done at the local mechanic.

am50em
Posts: 1539
Joined: Sat Aug 28, 2010 10:21 pm
Location: Sydney

Re: Pads for Shimano GRX BR-RX400 disk brakes

Postby am50em » Fri Feb 23, 2024 1:21 pm

https://www.uberbikecomponents.com/cate ... Brake-Pads have various compounds and finned variety. I find them to be quiet and wear well.

User avatar
Duck!
Expert
Posts: 9871
Joined: Tue May 21, 2013 8:21 pm
Location: On The Tools

Re: Pads for Shimano GRX BR-RX400 disk brakes

Postby Duck! » Fri Feb 23, 2024 9:48 pm

Mr Purple wrote:
Fri Feb 23, 2024 12:53 pm
Yeah, I'm leaning that way. The only thing holding me back is I'm not sure I can actually replace the pads without messing it up. So I'll check Youtube and if I'm not sure just get the whole thing done at the local mechanic.
There is no devillish rocket surgery involved with changing disc brake pads or rotors. Remove the retaining bolt/split pin, lift the pads out, push the pistons back with a softish tyre lever or similar, fit new pads & bolt/pin to secure. For rotors, Shimano Centrelock use the same tool as for cassettes, or if externally-splined lockrings (more on MTB), external bottom bracket spanner; 6-bolt types use a T25 Torx tip.

Contrary to some recent comments on the subject, the brake pistons will not "snap shut" when the wheel/rotor is out, so you don't need to have a spacer immediately at hand to stop them moving; the pistons will ONLY advance if the brake lever is squeezed. Don't touch the lever and you'll have no problem. Once the new pads & rotors are fitted and back in the frame, you may need to pump the levers a couple of times to reset the pad clearance. The process is considerably easier than replacing pads & resetting clearance on rim brakes....!

Brake rotors typically have a minimum thickness spec of 1.5mm but can be worn a bit thinner if you're daring, however Shimano's higher-spec (XTR/Dura-Ace/XT/Ultegra) IceTech rotors have a sandwich construction of very thin stainless steel veneers over an aluminium core; if the outer skins are worn through and exposing the aluminium core layer, they're due for replacement.

I'm not sure about the various aftermarket 3rd-party pads, but Shimano's finned pads are left/right (AKA inboard/outboard side of the caliper) specific; the fins are shaped in such a way that they will only fit in one side of the caliper.
I had a thought, but it got run over as it crossed my mind.

warthog1
Posts: 14380
Joined: Wed Jul 25, 2012 4:40 pm
Location: Bendigo

Re: Pads for Shimano GRX BR-RX400 disk brakes

Postby warthog1 » Sat Feb 24, 2024 8:23 am

Mr Purple wrote:
Fri Feb 23, 2024 11:43 am
Not sure if this is the right spot, but I don't really want to start a new thread for it!

How do you tell if your discs need replacement? I've got a set of Ultegra discs with 18,500km on their third set of pads. They've recently started making some decent screeching noises intermittently under dry braking and there's plenty of meat left on the pads. Their thickness is pretty much as new but the braking surfaces have some visible scoring in them. Seem to work fine, just intermittently noisy.

New disc time? And if I replace the discs am I likely to have to do any thing to adjust the pads?
If they still work fine, I'd just leave them as is.
Stopping well is my concern, noise is not. I aint on the brakes often enough to care.
Dogs are the best people :wink:

jasonc
Posts: 12207
Joined: Thu Feb 24, 2011 3:40 pm
Location: Brisbane

Re: Pads for Shimano GRX BR-RX400 disk brakes

Postby jasonc » Sat Feb 24, 2024 10:52 am

Duck! wrote:
Fri Feb 23, 2024 9:48 pm
Shimano's finned pads are left/right (AKA inboard/outboard side of the caliper) specific; the fins are shaped in such a way that they will only fit in one side of the caliper.
the Shimano pads are marked left and right. but they will fit on the other side. don't do it. it doesn't work so good

Mr Purple
Posts: 2876
Joined: Sat Sep 12, 2020 1:14 pm

Re: Pads for Shimano GRX BR-RX400 disk brakes

Postby Mr Purple » Sun Feb 25, 2024 2:48 pm

warthog1 wrote:
Sat Feb 24, 2024 8:23 am
If they still work fine, I'd just leave them as is.
Stopping well is my concern, noise is not. I aint on the brakes often enough to care.
Took it out on a very wet day and apart from the occasional screech you always get on a wet day and discs they were completely fine.

I suspect it was a little bit of contamination that sorted itself out.

Which suits me because I'm about 3000km from a new wheelset, new discs and pads anyway.

warthog1
Posts: 14380
Joined: Wed Jul 25, 2012 4:40 pm
Location: Bendigo

Re: Pads for Shimano GRX BR-RX400 disk brakes

Postby warthog1 » Sun Feb 25, 2024 3:33 pm

^^nice :)
Dogs are the best people :wink:

Who is online

Users browsing this forum: CoffsGal