Kinda perplexed by this. J04C Shimano metallic pads, BR-M6000 caliper.
I've been using very cheap generic ceramic pads for years. I wanted to see what official Shimano braking performance was like so I thought I'd try these for a while.
Even though they're not ceramic like my old pads ($10-ish total for front and rear), they're Shimano and they're metallic and I thought for $58 total for front and rear they'd surely last a long time.
But they lasted about the same or maybe even less than generic ceramic pads. I only noticed something was wrong when my rear brake was howling like crazy on a descent, and afterward I noticed how worn away the braking surface is. This happened at the 4 months mark, but since the surface was so thin beyond the point of replacement, in reality these pads probably only really lasted 2 or 3 months before they were too thin to use.
The picture is for my front brake, which really surprised me since usually only the rear gets hits with that much damage so quick. The rear are looking even worse.
Questions:
1) Is this because they were metal and not ceramic? Shimano doesn't even sell ceramic pads with wings from what I can tell. Should I just go back to third-party ceramic for more longevity?
2) What's causing the pitting on the bottom of the brake surface? I tried to do everything right: align the calipers, used business cards to create a gap, etc, and kept rotors clean.
3) Is the top third of the brake surface left intact a problem, or are Shimano pads supposed to do that? To clarify, I have a 180 mm rotor in the front and my BR-M6000 caliper came with an extension part for 180 mm rotors, so I thought everything would line up and work fine?
Unfortunately I can't really be spending close to $60 for brakes every 2 months, so I'm hoping someone can tell me what the issue was or what third-party ceramic pads with wings exist that I can be using instead.
by lectric_7166
13 Comments
just from the picture…. do you notice something?
look ath the pads themselves and maybe you see the issue
hint:
>Is the top third of the brake surface left intact a problem, or are Shimano pads supposed to do that?
no and no
Pretty sure your brake caliper adapter situation is very wrong with that much pad unused
Senpai, only half your pad is used…
How much unused pad is there up top? Looks like maybe 5mm? Do you have some rogue 170mm adapter on a 160mm rotor? It’s a common enough mixup with 200mm and 203mm rotors, but that only leaves 1.5-2mm of unworn pad at the top. Either way, no matter the measurement, def need to get the mount/adapter to rotor mismatch sorted out.
Oh, maybe it’s just an adapter mounted backwards. Check everything between the fork/frame and calipers.
The picture should tell you everything. With brake pads you want to use majority of the brake surface and the brake pad, so, the brake pads should be evenly worn down, you’re losing out on braking power and likely seeing 2x+ the wear (assuming the smaller brake surface has to do even more work). Also this is a safety concern as the upper unworn pads will hit each other before clamping down on the brake rotor.. So, your brake caliper-frame adaptor is incorrect. You either just have a flat out wrong adaptor (due to brand differences), backwards, or rotor or adaptor itself are mixed up.
For additional context, I have run into bikes (my bike included) where even though the rotor size and brake adaptor size were the same, some adaptors-caliper brands required slightly different adaptors or considerations.
Question to OP. Do those 3rd party ceramic pads contact the rotor the same way? Likely the alignment, adapter, etc is off/wrong. Pics of bike setup and pads on the bike would help.
Is this problem only on the back or is it also on the front?
It may be that the piece between caliper and frame is set backwards. The adaptor when flipped will set it for a diffrent sized rotor and would be an easy mistake.
You might have used the incorrect spacers on the caliper, or the adapter might be incorrect . The calipers are set too high up, which makes only part of the pad hit the rotor. That or you have the wrong rotor size. Can you post a photo of how the calipers are mounted to the frame/fork?
You got the wrong rotor or adapter size bud
The rotor is only hitting 2/3 of the pad, so something isn’t right. And because of that, you’re prob braking pretty hard which further chews the pads down.
Wrong rotor size; wrong adaptor; wrong pads/installation : take ur pick
You brake hard! Looking at the alignment the pads aren’t sitting over the disc fully. I shitted off my shimano brakes immediately, just find any other brand and don’t go over 160-180mm rotor
I think there’s two problems going on, first you have a mis-match between rotor size and caliper mount, that’s why the top half isn’t worn. Second 2-3 months of use there’s no way that much should be worn, even with the mis-match. Where did you get the pads from? There’s a lot of counterfeits of Shimano pads that are much lower quality….i wouldn’t be surprised if you somehow ended up with fakes.