FlashBazbo

Yeah, I understood that the first four times you posted it. I understand your position. Our experiences with maintenance of disc brakes are obviously very different.

MoAlpha

Indispensable tools for sure.

I bought a fairly simple Fluke for my lab many years ago (with taxpayer funds). I have two cheapish ones at home—needed to get the second one for the Hall effect pincer, and a credit-card size, but totally functional, one in the tool box on the boat. I think one of mine reads capacitance.

Seattle Forrest

Just a random curiosity on my part. For most people it seems to be one io the other.

redlude97

a set of shimano pads lasts you 8000 miles? Resin? I get around 1000 out of a set of fronts and double for the rear, but we do get a lot of rain and quite a few hills around here

FlashBazbo

Yes, no problem at all. I've never worn them down near the backing. And I live in an extremely hilly area -- base of the Cumberland Plateau / Smoky Mountains -- but I rarely have to use my brakes. Maybe that's the difference. Do you live in a city or suburb where you have to use your brakes every block or every mile? I mentally went through a 70-mile ride that I take at least once per month from my home. In those 70 miles, there are 6 stop signs and 3 stop lights. The descents are 8% to 15%, but there aren't stops at the bottom -- no reason to use brakes. When I ride gravel, I tend to steer using the rear brake, so those pads wear more quickly -- but I don't ride nearly as many miles on gravel, so those pads still last a year or two. If you live in a more congested area, you probably use your brakes a lot more times per mile than I do. (I probably average about 1 brake application for every 10 miles.)

redlude97

yea thats probably it, mostly commuting with a pack in an urban setting with hills and rain with lots of stops

Cyclist0108

It is highly dependent upon how much you use them. In my case, I wear through probably 4 sets of pads per year, and one set of rotors per year. So $250 in parts, and I do my own labor.

I have yet to find anyone posting here who is as extreme a case as I am, so I think you can fairly safely regard this as an upper bound.

Psimet2001 

For the record We can leave the generational bit out of this one.. Her boyfriend just doesn't like tools. I'm GenX and have made a living with tools (mechanical, electrical, plumbing, machining, and even computer based tools) my whole life. I know older people who have as well as younger people.

Just like there are people who will never work on their own stuff no matter how easy we make it there are people who will always do the opposite and work on everything regardless of how hard it is. That spread across generations seems pretty consistent.

Campag4life

I will push back a bit Rob and even evoke an old wives tale. Necessity is the mother of invention. Tech is evolving the old standard. Modern tech isn't designed for reconstitution like the old stuff was...in the day of TV repair and Hi Fi shops...and tube testing at the local drugs store. New stuff...not all...is more throwaway. More computers and integrated circuits. Even computer repair is now more rare. Bad motherboard?...even $30 power supply and the computer goes in the trash. Buy a new one with operating system already installed. Younger people today generally 'work on stuff less' than the aging baby boomer gen...my generation...in part because that is how things were designed back then and we had to. A more primitive time. Go back even farther to the time of the Model T which was a very basic machine and much less complicated than a riding lawnmower today..., 'real men' worked on their own cars. They replaced broken parts which were also more prevalent because design verification testing in those days wasn't performed at all or on a limited basic. Lessons were learned out on the road and applied to future products. Many cars now will go 200K miles without replacement with adequate care...adequate care being rare because people are still ignorant about machines.. How many people still work on their cars? I do but extremely rare now. Vast majority of people I know don't.

You and I are similar even though I believe I am older. Both graduate engineers that like to work with our hands. Btw, you know that many engineers can't do what you do or what I do. I have worked with countless. It is largely a DNA thing and yes does cross generational lines...but...back when I was little, we built our own stuff from scratch. I built my first minibike from a bicycle I combined with tubing and cut the base of a horizonal shaft lawnmower off with hacksaw and U clamped to the make shift frame. Wish I had a picture. It had a mercury clutch and solid wheelbarrow wheels. That was my first minibike. My second, was much more refined. I built everything. I just don't see kids doing that today. They buy stuff. They buy their first minibike or their parents do for them. My experience.

I don't know anybody in my town who can tune a bicycle as well as me. Maybe at the bike shop but they generally don't because they don't have the time...or are too busy.

I know there are some brilliant kids coming up building stuff. Don't believe kids today have the hands on experience because they don't have to and many things aren't built for service like they were back in my day.

Will leave you with a funny story you may appreciate as an example that society with its throwaway nature hasn't changed that much. 50 years ago when I was 10 years old and I walked into a lawnmower shop and asked the man behind the counter if he had a 3hp Briggs and Straton with horizontal shaft in the back room he would sell me cheap for a go kart... he looked at me carefully and said yes I do sonny and can pretty much guess what is wrong with it. 5 bucks and its yours. What is wrong with it sir?...I asked. You called adults sir back then. Flywheel key. We change a lot of engines because the fly wheel key shears and the motor loses its timing. Throwaway perfectly good engines because of a sheared flywheel key.

Years later when I was in college and home for break there was a little kid on the end of my street who couldn't get his minibike to run. I saw the kid working on it and he reminded me of me. It had a Briggs on its like many did back then. I said, well let me take a look at it. I removed the flywheel and the key was sheered but not broken. I told the kid to hand this to his Dad and go to the lawnmower shop and pick up a new 50 cent (in the day) key. He said he would. I installed it for him and the kid was back up and running.
His Dad found out about it and gave me a job while I worked myself through engineering school. What goes around comes around.

vtje

Hi, out of curiosity, why do you replace rotors? I have been riding mountain bikes for a number of years and the only time I replaced a rotor on my DH rig is when it got bent. Thanks!

WhyFi

I'm assuming that they're reaching the manufacturer's min thickness spec or close enough that it makes sense to do it on an annual schedule.

Cyclist0108

They wear down. Not as fast as the pads, but they still wear thin. Once they wear thin, braking deteriorates, and there is too much play in the lever. I let them go a little bit past the Shimano recommended replacement thinness, but if you go too far, you break through the outer surface, and then things really go to hell.

Compared to road biking at high speeds in the hills, mountain biking isn't that hard on your brakes (unless you are doing a lot of downhill racing). Also, I think the rotors are a lot larger for downhill, which means much more surface area to spread the wear around, and better heat dissipation, both of which probably contribute to longer life.

Having said that, you probably should get new rotors and pads before you think you need them.

Cyclist0108

You guys do realize that Generation X (as defined by the guy who wrote the book with that title) started as early as 1961?

I was born in 1963, and definitely identify with GenX rather than post WWII-BabyBoomers. (Their whole mind-set is very different, but I have no idea how that would extend to tool-use, which dates back to the origin of old-world primates, as well as some of Darwin's Galapagos finches.)

Cyclist0108

Your experience is like mine. How long does your front rotor last? I'm guessing about 4000.

Campag4life

I explained it.
Further, level of affluence affects capacity of junior to go out in the garage and build something. Gen X'ers by and large have been richer raised by Boomer's who have given them more stuff. If Junior is given everything, he isn't inclined to build anything.

Seattle Forrest

​​​​​​That's surprisingly close to what I get out of mine. Lot of hilly urban miles, and unpredictable drivers.

JasonD67

About to get my first disc bike so forgive my ignorance...curious if there is any type of aural pad-life indicator like one would find on automotive disc brakes (i.e. little metal tab that makes a horrendous noise when the pad wears away).

jadocs

There is a spring catch that is made of metal but you don't want it scraping your discs as an indicator of when they need to be changed. You should check the pads periodically and change them if they get too close.

Kapusta

NoWhammies

Do you have a caliper to measure the thickness? And can you point me in the direction of the specs re: replacement thickness? Thank you.

JasonD67

No, the automotive ones are there to warn you ahead of time that your pads are getting thin:

superpletch

bike disc brakes operate identically to automotive disc brakes, which have proven to be very maintenance friendly and perform very efficiently.

there is no reason to bleed brakes unless the hydraulic system is opened due to leak or replacing a defective component. when is the last time you bled the brakes on your car unless the mechanic upsold you to a brake fluid flush? the brake lever pull will slowly fade as the pads wear and when they are replaced brake lever returns, same as your brakes feel better on your car when you replace the brake pads. Your cars brakes do not require bleeding when replacing pads, nor does your bike. overheating brakes can cause damage but that is extreme and unlikely and just a likely to happen with rim brakes.

there are certainly two camps and both systems work well and continue to improve with technology.

I would certainly prefer disc brakes on my loaded touring bike, rim brakes are great on a light road bike.

bikeaddiction1

Brakes need to be bled when the feel at the levers starts to get soft or spongy. There is not a hydraulic brake system out there that does not eventually get contaminated with dirt and moisture, ever if no components have been changed and there is no sign of leaks. Typically the systems I have flushed (both mineral oil and DOT fluid systems) have been because of the feel becomes spongy. Some riders are more particular about this "feel" than others. The fluid usually is darker showing signs of this contamination. I have also seen brake systems left too long and then you end up with a very contaminated system and need to flush through more than once. I am on the picky side of not wanting any soft feeling in my brakes but we have lost of hills and it is a safety thing.

jadocs

So if you look at the top you will see the spring clip I was talking about. If you look at the bottom right you will see the relation of the pad to the spring clip. You do not want the pad wearing down to where the spring clip comes in contact with your disc.

Campag4life

In bold above, you haven't been around many auto repair shops...lol.