I have GRX400 on my gravel bike, I believe these come with L03A resin pads and for sure come with SM-RT54 (Deore) rotors, 160mm front and back.
I don't live in the mountains and mainly engage the brakes for short descents (usually no more than a couple hundred meters); I do ride in the winter, mainly when the roads are free of snow/ice, but sometimes in conditions with wet roads and traces of salt (after those rides the bikes gets a good cleaning). I also have a road bike so this bike is used around 1/2 my riding in a year (I don't track KM with a computer, but maybe a 2-4k a year on this bike).
- How long would such pads/rotors last (generally speaking)? - Do you usually replace the pads 1-2x per set of rotors, or pads/rotors at the same time?
If/when I need to replace them, I have to say these work perfectly well for me and they're affordable, so any reason to select different pads/rotors (for rather tame gravel riding)...I wouldn't think so?
Maybe five years ago I put a new fork and Shimano mechanical disc brake on the front of an old bike. The Shimano pads wore quickly, not surprising since I descend at least 500 m every time I ride. I found Swissstop pads lasted a lot longer but I don't remember any difference in braking. Of course this is old news, Shimano may have improved their pads a lot. But it wouldn't cost much to try a few alternatives.
Brake pads replace them as needed, just pull them out and check them every once and awhile. I have only replaced a rotor once and that was because it was warped, they should last for a long while. I have used discs for years on MTB's and now gravel as well and haven't really had any problems with rotors or much of anything to do with the braking system. I use Shimano pads and they seem to work fine, pretty much all my stuff is XT/ 105 level. Having said that I try not to use my brakes as it slows me down- haha😁😁😁.
Pads might last for a few thousand miles, depending on how much braking you do and how often you ride and brake in inclement weather. I've had brand new shimano GRX 800 stock pads (can't remember the letter/number designation) completely wear out on a single 100+ mile gravel rides in wet sandy conditions. Rotors...I can't see needing to replace one for years based on what mine look like.
I use those same rotors and resin pads, and like this approach for low cost and performance in wet conditions. If I did the riding you describe I would simply check the thickness of the pad material once per year and replace at ~2mm remaining. The rear pads will wear more slowly but I'd go by the front pads and replace them together anyway. Because these rotors are inexpensive, I'd change them every other set of pads. My recommendation is conservative but, as with tires, it pays and I doubt were talking more than $20 per year. For reference, I'm 250 with bike and ride about 2,000 miles and 200,000 feet per year. Very rough guess - I probably go through 10 sets of pads and three rotors every two years. I treat front and back separately and monitor rotor thickness with a caliper, but I like to tinker and in your case I see no need to bother.
I'm 200 lbs and ride a mix of road and gravel. My rear pads (resin) most recently lasted 3,500 miles and 250,000 feet of elevation. The front pads are still going strong, I think because I avoided them at first because these were my first hydros (fearing an endo) and because the bike shimmies a bit so I unconsciously used the rear as a drag brake; I have improved my braking technique a little but the pads are way behind in wear. The rotors appear like new.
This is a bit off topic but when I went to remove the rear pads I could not; the retention pin had fused to the caliper body somehow. These are 105. Rarely discussed in online forums but it does appear. All my efforts to remove them were in vain. I ended up just replacing the caliper, which I found on sale. So essentially an expensive pair of pads. This episode has been burned into my memory such that from now on I will check to see that the pin is greased and turns every so often. Silly pin design, really.
If you know you'll be riding a lot in wet gritty conditions, you might want to swap in a set of metallic pads. They'll last longer than resin pads in that kind of abrasive slurry.
That's not to knock disks -- those same conditions would chew up your rims on a rim-brake bike.
Editorque wrote:I'm 200 lbs and ride a mix of road and gravel. My rear pads (resin) most recently lasted 3,500 miles and 250,000 feet of elevation. The front pads are still going strong, I think because I avoided them at first because these were my first hydros (fearing an endo) and because the bike shimmies a bit so I unconsciously used the rear as a drag brake; I have improved my braking technique a little but the pads are way behind in wear. The rotors appear like new.
This is a bit off topic but when I went to remove the rear pads I could not; the retention pin had fused to the caliper body somehow. These are 105. Rarely discussed in online forums but it does appear. All my efforts to remove them were in vain. I ended up just replacing the caliper, which I found on sale. So essentially an expensive pair of pads. This episode has been burned into my memory such that from now on I will check to see that the pin is greased and turns every so often. Silly pin design, really.
The last part is a very good tip. I've replaced the grx flathead screws with mtb versions for a few usd each. They are slightly longer(no issue) but more importantly offer a head with Hex!
RT-54 rotors are for resin pads only, don't use with metallic pads. My Shimano road/gravel hydraulic disc brakes are pretty new so I haven't had to change anything. On my mountain bikes, I get a few hundred to around a thousand miles per set of pads, and I think I wear the rears faster than the fronts. I've pretty much just kept using resin pads even though I could use metallic on a couple of my bikes. I've tried a few non-Shimano brands of pads, but always came back to Shimano. I had a bike with TRP mechanical disk brakes and the pads wore really well. Not sure the TRP pads fit Shimano, however.
Seems like these pads will be good for at least this year.
@Aesch where did you get the MTB version of the screws, online or through LBS?
On a slightly different topic...when I got this bike the front rotor was rubbing and it took a while to solve that. Now, after a long hard gravel ride where I used the brakes a lot, the back is rubbing. The caliper mounting bolts face the floor and it’s hard to adjust, and to backlight for spacing...any tips? Thanks
