Uneven front brake pad wear

On my front hydraulic brakes, the inside pad closest to the hub is fairly thick, but on the other side I can't see any pad at all. Coming down a steep hill there was some screeching and the brakes weren't gripping and stopping well. Is this an install problem? Possibly something worn out or warped? The disc rotor has visible marks on it but no scoring or grooves. The front brakes are Shimano Deore 160MM Hydraulic. I get them serviced regularly at a professional shop.

UPDATE: The shop replaced the front and rear rotors and both sets of pads. Cost for labor and parts, €120. The rotors were quite worn and the thickness was below the suggested minimum. These were upgraded to Shimano SM-RT66; the stock rotors were the cheaper SM-RT56S. One thing I did not know: The 56S is softer metal and only resin pads should be used. The RT66 allows semi-metallic or resin pads. The 56S rotors lasted for 10,340 KM, with a lot of hard wear, and at least one set of semi-metallic pads that shouldn't have been used. I imagine the RT66 should last maybe 15,000 KM.
 
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fooferdoggie

Well-Known Member
On my front hydraulic brake, the inside pad closest to the hub is fairly thick, but on the other side I can't see any pad at all. Coming down a steep hill there was some screeching and the brakes weren't gripping and stopping well. Is this an install problem? Possibly something worn out or warped? The disc has visible marks on it but no scoring or grooves. The front brakes are Shimano Deore 160MM Hydraulic. I get them serviced regularly at a professional shop.

The bike as 6300 miles on it, and lots of hard braking due to the many steep roads around here. Sometimes there's a 1500 to 2000 ft. elevation gain in a few miles.
they may not be centered well or a piston is stuck. but it would be time for new pads anyway.
 

Jason Knight

Active Member
Region
USA
City
Keene, NH
they may not be centered well or a piston is stuck. but it would be time for new pads anyway.
The cute part being that it seems the former can lead to the latter. More I learn about disc brakes on bikes, the sketchier the tech seems at this small scale.
 

retiredNH

Well-Known Member
Region
USA
The cute part being that it seems the former can lead to the latter. More I learn about disc brakes on bikes, the sketchier the tech seems at this small scale.
You prefer rim brakes? Geesh, even the worst disc brakes seem miles ahead of the rim brakes we had just a few years ago. I can't imagine rim brakes on an ebike, given the bike weight and greater speed potential. Yes, discs need adjustment and wear out. So do rim brakes, but even more frequently.
 

TrevorB

Active Member
You prefer rim brakes? Geesh, even the worst disc brakes seem miles ahead of the rim brakes we had just a few years ago. I can't imagine rim brakes on an ebike, given the bike weight and greater speed potential. Yes, discs need adjustment and wear out. So do rim brakes, but even more frequently.
The Magura hydraulic rims are very good and on par with entry level disk pads. Both have pros and cons when comes to maintenance.

Back to problem at hand. Most likely piston on one of calibers is sticking. There are few videos on maintaining these on youtube. Remove pads, clean caliber with isopropyl alcohol/brake cleaner, I use cotton buds. Force each piston out by holding other in place with cable tie or tool while applying brakes. Clean around piston then lube with brake fluid. Cleanup with cloth don't use cleaner as it wash away fluid which you what for lubrication. Hopefully both pistons should move evenly now when brakes are applied. Push pistons home by fitting old pads and using screwdriver to lever apart, then fit new pads. Keep a set of olds pads for this, never use screwdriver directly onto pistons.
 

EMGX

Well-Known Member
You prefer rim brakes? Geesh, even the worst disc brakes seem miles ahead of the rim brakes we had just a few years ago. I can't imagine rim brakes on an ebike, given the bike weight and greater speed potential. Yes, discs need adjustment and wear out. So do rim brakes, but even more frequently.
That might be your experience, not mine. I have bikes with rim brakes and bikes with disc brakes, they both work fine. I live on a mountain with steep grades and coasting speeds up to low 40 mph even scrubbing off speed with brakes. I prefer rim brakes, they last longer, pads are inexpensive and easy to adjust and monitor, I'm on my third set of Shimano disc brake pads on one bike at $35 a pop although I've started to use generic pads which work just as well for $15 to $20 less. Hydraulic discs can be a hassle changing brake fluid or if you happen to get air in the system which happened to me out in the middle of nowhere, brakes dragged in the heat. To each his own.
 

EMGX

Well-Known Member
This.


The rims do not. And I wouldn't apply rim brakes on expensive modern rims. Also, rim brakes fail during rainfall.
Discs can wear out, rims can wear out - I don't worry about it, I'd replace them if I ever need to and might be getting close on one set of rims. Regarding rain, I live in the rainy pacific NW, I generally avoid riding in the rain and am more cautious when I do but when I have I've had no problems with rim brakes slowing and stopping my bike. Loss of tire traction has been more of a concern than brakes.
 

Stefan Mikes

Well-Known Member
Region
Europe
City
Mazovia, Poland
Discs can wear out, rims can wear out
Disks are inherently cheaper than the rims, and they wear very slowly. Rotor replacement is far easier and cheaper than rebuilding the wheels.

Regarding rain, I live in the rainy pacific NW, I generally avoid riding in the rain and am more cautious when I do but when I have I've had no problems with rim brakes slowing and stopping my bike.
Many of us ride all year long disregarding the weather. Never experienced any tyre traction issue but again I use good tyres. Necessary to mention I ride spiked tyres in the wintertime.

On one of my mountain rides, I had to cover a long and steep descent of totally cracked asphalt; it was impossible to be riding fast so I was using my disk brakes intensely. Down there in the valley we stopped. I touch the front rotor... to burn my fingers. I wonder how rim brakes would have fared there. (Good rotors are made to cool down as soon possible; it says something on that specific downhill ride!)

I often go for group rides with gravel cyclists. All of them use hydraulic disk brakes! Unlike roadies, gravel cyclists need to brake often, and it is often rain and mud.
 

TrevorB

Active Member
Rims have lot more surface area and mass which means heat build up isn't issue. A 650 rim has 4 times surface area than 180mm disk so in theory 4 times life.

Some of Dutch style ebikes are still using hydraulic rim brakes as they are lot more forgiving in old style bike racks. These like bending disks. For most users of these bikes the rims will last life of bike.
 

fooferdoggie

Well-Known Member
Rims have lot more surface area and mass which means heat build up isn't issue. A 650 rim has 4 times surface area than 180mm disk so in theory 4 times life.

Some of Dutch style ebikes are still using hydraulic rim brakes as they are lot more forgiving in old style bike racks. These like bending disks. For most users of these bikes the rims will last life of bike.
of course heat buildup is an issue. its actually worse. tandems really had this use when decending with only rim brakes. but the problem is if you rim overheats your tire can blow off. I have heard of way to many people with this issue. people who had to stop and let their rims cool off on long decent.
 
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Jason Knight

Active Member
Region
USA
City
Keene, NH
You prefer rim brakes?
Actually I prefer coaster brakes, but then I don't hot rod around like a maniac. I'm a comfort rider, only reason I got the Aventure was the fatties being better on snow. A promise they delivered on.

I find it comedy how my simple statement set off a firestorm of evangelism both for and against.

Though a LOT of what rim brake detractors are saying sounds like total BS unless the technology has changed for the worse in the decade plus I was away from bike tech. When a rubber rim brake is destroying your rims, what the hell rinky sleazy material are your rims made from? Much less heating up enough to blow tires off?

Again I'm a decade, maybe two behind on the 'tech. And there's always been a lot of bicycle tech I've found sketchy, dubious, and kind of based more on wishful thinking than engineering. See "derailleurs". Jumping a chain between cogs by applying shearing force and letting it skip through mid-air is about as jank a concept as you'll find. But it's cheap and it works. So maybe not THAT janky.

But to be fair, I have already gotten the zoom brakes on my Aventure to blow smoke coming down a hill... that I used to go down on my cruiser with coaster-brakes problem-free. I'd say it was the increased weight of the bike, but when I first started riding the cruiser I had another 100 pounds on me... I will say pad replacement -- rim or disc -- is a hell of a lot nicer than cracking open the rear hub.
 

fooferdoggie

Well-Known Member
Actually I prefer coaster brakes, but then I don't hot rod around like a maniac. I'm a comfort rider, only reason I got the Aventure was the fatties being better on snow. A promise they delivered on.

I find it comedy how my simple statement set off a firestorm of evangelism both for and against.

Though a LOT of what rim brake detractors are saying sounds like total BS unless the technology has changed for the worse in the decade plus I was away from bike tech. When a rubber rim brake is destroying your rims, what the hell rinky sleazy material are your rims made from? Much less heating up enough to blow tires off?
coaster brakes? I guess if you putter around its ok but it is not going to do crap if you have to do an emergency stop locking the rear up is the worst way to stop. there are plenty of stories of overheating rims. Plus aluminum is soft and grit on the rims will wear them out pretty well. this is why tandems used to come with drag brakes before disc brakes were the norm. all brakes can overheat I have overheated our tandem brights slightly on long steem decents try to keep the speed to 25mph.
 

EMGX

Well-Known Member
Actually I prefer coaster brakes, but then I don't hot rod around like a maniac. I'm a comfort rider, only reason I got the Aventure was the fatties being better on snow. A promise they delivered on.

I find it comedy how my simple statement set off a firestorm of evangelism both for and against.

Though a LOT of what rim brake detractors are saying sounds like total BS unless the technology has changed for the worse in the decade plus I was away from bike tech. When a rubber rim brake is destroying your rims, what the hell rinky sleazy material are your rims made from? Much less heating up enough to blow tires off?

Again I'm a decade, maybe two behind on the 'tech. And there's always been a lot of bicycle tech I've found sketchy, dubious, and kind of based more on wishful thinking than engineering. See "derailleurs". Jumping a chain between cogs by applying shearing force and letting it skip through mid-air is about as jank a concept as you'll find. But it's cheap and it works. So maybe not THAT janky.

But to be fair, I have already gotten the zoom brakes on my Aventure to blow smoke coming down a hill... that I used to go down on my cruiser with coaster-brakes problem-free. I'd say it was the increased weight of the bike, but when I first started riding the cruiser I had another 100 pounds on me... I will say pad replacement -- rim or disc -- is a hell of a lot nicer than cracking open the rear hub.
Somewhat amazing to me is the price of the very simple material/tech bicycle components. $35 for one set of Shimano 105 compatible pads that have the combined friction surface of less than a postage stamp. I can buy a good quality axle set (4 pads) for my F350 that will stop a 8,000 pound vehicle from high speed, plus with few thousand pounds of cargo in the back, for that amount. 6 years ago I bought a new hand assembled 750cc Italian made motorcycle with ABS and traction control etc for just over $7,000 which is not much more than a higher end ebike with not a tiny fraction of the engineering, tech, materials and workmanship. More amazing to me is that anyone thinks that the cost is justified by the product.
 

Jason Knight

Active Member
Region
USA
City
Keene, NH
SMore amazing to me is that anyone thinks that the cost is justified by the product.
I often have the same feeling, but there's three things you need to factor in.

1) At this miniaturized scale there's a lot less margin for error in manufacturing. You also are trying to use a much smaller object to punch way above its weight. Sure each pad is the size of a forever stamp, but it has very little mass particularly in thickness to dissipate its own heat. It is also being used to brake on a smaller contact patch. Miniaturization -- part of where I find it a bit of ice-skating uphill-- comes at a cost.

2) Economies of scale. The lack of standardization, and the fact that manufacturers are going to sell a lot less bicycle brake pads than they do motorcycles or cars is going to drive up the price. The more of them you make, and the more uniform and universal they are, the lower the price.

3) Some people will spend crazy money, and greedy corporations know it. Look at sleazy dirtbags like Apple for proof enough of that. What with all the gullible ignorant fools they saddle up and take for a ride with their rinky overpriced half-assed products built entirely on "form over function", anti-consumer practices, and four plus decades of lies. If any other company pulled half the stunts crApple has the past 44 years, everyone involved would be doing jailtime. But through marketing, propaganda, and "status symbol" cult-like worship, they get away with it letting them charge a grand for something that probably shouldn't cost more than a quarter that.

A similar situation can be found in the "pay to win" mobile gaming space. Someplace I worked briefly and quit because it was too dishonest and borderline criminal. They don't actually care about mass appeal of their games. The entire "free to play" model isn't based on normal people, it's based on landing a half dozen "whales" who will drop tens of thousands of dollars into "winning". That's actually the industry term for the big spenders in games. "Whales".

We seem to see that same thing in bicycle tech now. People who will spend crazy money on a bicycle not for quality, but for the brand logo printed on it, the illusion of prestige. Bragging rights. Even when the product is indistinguishable from a XenSheHowSheWhaShe random word jumble brand from China. Worse there seems to be so much "tech for bragging rights" that keeps the hobby out of the hands of "normal people", and those so privileged seem unaware of their own status. The way some folks look down on those for whom a grand is a back-breaking investment reeks of country-club levels of dirtbaggery.

See some of the crazy stuff in terms of chains, chainwheels, and cogsets that are in reality no better than $20 or less Amazon specials. Unless you're a professional racer, you're just lighting money on fire.
 
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