I have had my gravel bike for just a little while, maybe 150 miles or so total. It has GRX 400 hydro brakes and GRX 600/800 drivetrain. I've done a few events, one of them a "real race" (which I medaled 3rd place in the Clydesdale "dad bod" category). The race was mostly in the wet and high difficulty (repeating steep elevation, rapid descents on destroyed wet muddy roads, and a bunch of MTB-like terrain) -- muddy water everywhere for 30 of the 40 miles. It was fun, and my bike was absolutely trashed afterwards. After a 2-hour de-construction and cleaning/servicing fest, it's fresh again... except for my rear brake and front GRX 810 derailleur that will need repair. Part of the game, I guess, but I'm a little surprised how quickly these components failed.
About 1/2 of that race my rear brake was dragging something fierce -- even walking the bike was more difficult than normal with the rear tire almost locking up on slick ground if I was hike-a-biking (had to twice). When I got home and I took the bike apart to service and clean it, I saw that the inner pad was entirely worn down with the metal backing exposed (the other pad looked nearly new and my front pads looked the same). The piston for the worn pad was extended out as far as it'd go before probably popping out and it's absolutely stuck (it won't go back in at all). The bike is going to the shop Thursday to get that fixed along with the front derailleur (which may just have suffered some cable stretch... hopefully). Honestly, a lesson learned for me... I might never have a front derailleur on a gravel bike again... it failed within the first 10 miles (this is before the rain storm hit, turning the course into mush) and I found myself shifting multiple times to get through the close ratios on the rear cassette. I wasn't going to be remotely the fastest rider, but these issues severely slowed me down and forced me to consume much more energy than I would have had to if I wasn't overcoming these two failures. Annoying, no doubt, but, again, part of the experience. Again, I'm just a bit surprised...
I'm new to gravel bikes, coming from mostly hard tail MTBs and adjacent riding and bike commuting on a steel "hybrid" I built. I guess I would just be interested in understanding from more experienced folks if the issues I experienced are expected/common? Would it have been possible for me to remove the pads from the rear brakes during the race if I had noticed this issue during? Or would that just result in destroying the caliper?
These things can happen to any bike in those kind of conditions. Removing pads in a race is not a good idea, best thing would be to try to push the pads back in, or recenter the caliper. But more importantly, run sintered pads. Carryng an extra set in those kind of races is a good idea also. Most road/gravel brakes come with organic pads because they are quieter, but they are pretty much useless in wet/muddy conditions.
The brakes were good enough the entire race, except the rear was dragging. My MTBs have sintered pads since birth so I guess I hadn't thought to change out the resin pads my gravel bike came with. I didn't even think to check what kind of pads it had, actually... my bad. I already ordered a set of sintered pads (Swissstop Yellows) just because I liked to have backups on hand so I guess I'll switch them out sometime before my next event, which is in March. Hopefully just a one time thing after it's fixed or replaced because that was a PITA to fight for over half a race. As fun as it was to slush through the slop and wet on a drop bar bike, I'm not impressed enough with GRX component durability now to be motivated to do it again if I can avoid it. I'd rather lose my entry fee than have to replace/fix damaged parts at a much higher cost. I've already been told by the dealer over the phone I'll have to pay to have the derailleur serviced and the brake caliper fixed despite having the bike for such a short time and mileage (I guess I shouldn't have mentioned my little outing). I mean, I have been through hell with the MTBs and a firm spray of water from my water bottle has always cleared up anything acting "stuck". Not with this gravel bike (I blew a whole water bottle trying to clear these parts up)... lesson learned.
I have found GRX (8xx series for me) to have very good durability, like most things Shimano. It is too bad you hav had this experience. It might be telling to know more what happened to your FD though... If you encounter really sticky clay type mud, this can break just about anything, and it gets especially bad in the FD area. I agree that 1x is often the best bet if one is gong to be dealing with mud, as it is just too easy for the FR area to get all clogged up, and the clearance between the FD cage and the rear tire is really minimal on most gravel bikes. As for the brakes, yes, for wet conditions one should change to the semi-metallic pads, as the resin pads just disappear too fast in the wet. I have had zero problems with Ultegra brake calipers on my Gravel bike (same as GRX 8xx series parts), but I do some maintenance on the calipers to avoid sticky pistons. Once a season (I ride in mostly dry conditions), I will clean around the brake pistons: Remove pads, and wipe away dirt from the inside of the caliper. Then hold one piston in place with a tire lever, while squeezing the brake lever, to extend the other piston out (watch closely and avoid popping the piston all the way out!). Now clean around the outer circumference of the piston with cotton swabs and 99% isopropyl alcohol. When you have the piston all cleaned up, let the alcohol dry, and then lubricate the piston with a little Shimano Mineral oil. Now push that piston back in, and do the same procedure with the other piston. This process keeps my brakes working really well, and I usually do it only once a season (I ride 12-15 hours a week in season, usually at least 8 of those on the gravel bike). If riding in the wet a lot, you may have to do this a little more often. Racing tends to push the limits of everything, so if you race, you must accept that additional maintenance may be required, but again, I find Shimano stuff to be the best when it comes to durability, it is just like anything, problems can occur in extreme situations.
It was wet and certainly muddy as a result, but not deep mud. It was just basically dirty water that was getting on the bike. Probably sandy water. When I took my bike apart, not having sprayed it down with a hose or anything after (just that water bottle spritz during the event), the inside of my brake caliper didn't have much of anything in it. The piston was just... stuck extended and that's really odd to me because I barely used the rear brake more than just a light pull. Don't use rear brakes much on drop bar bikes for some reason... guess I don't like how they (or I) react to it. But I can't even push this piston back in and it's clean as a brand new whistle right now.
Yeah, that seems weird... Could be bad brake set up, or it could be a defective part, which happens occasionally. Never had it happen to me, and I have been running Shimano calipers on MTB and now on gravel bikes ever since disc brakes were first introduced (have also used Hope on one bike). Sounds like bad luck, which happens sometimes. I would suggest that a single bad experience, although very annoying, is not indicative of a general "problem" with Shimano brakes.
Fair enough, but compounding with the issues I've had with this new bike I'm a little ticked off and critical. I'm waiting for the manufacturer to do the right thing before I explain any of that further. But on top of that, I really expected more durability from "gravel" components. As far as I can tell, they aren't much different than road.
