Polaris OBark

I go through a lot of Shimano disc brake pads. I usually take them out when they are thinner than 0.9 mm, which is what Shimano officially recommends. Because of the pandemic-induced shortages, I have tried to push it a bit further, and am now replacing them when they start to make noise or feel substandard in braking power, and I've noticed they have this delightful dog-bone wear pattern that is revealed when they are approaching the point where the rotors will be damaged.






Is the 0.9mm Shimano recommendation excessively conservative, or reasonable? I understand why, if someone brings a bike into a shop, you shouldn't send them home with pads that are 85% worn down, but if you monitor them closely, that last 0.4mm might be worth preserving when these are unobtainium.

Iride01 

It's not so much the pads and their braking ability, but the fact that the pistons will be further out of their cylinder and that makes for the possibility of them getting skewed in the cylinder and scoring or damaging their walls. Along with the increased problems for seals and such trying to keep dirt and grit out of places it shouldn't be.

I'll happily replace them at the recommended times when I'm able to. I won't worry if let them go longer because I can't find any compatible pads. Though I'll understand that I might be risking having to buy an entire brake assembly because of the potential negative impact on the brake pistons and cylinder.

I might could let Disque pass, but is ware and boan really the correct translation of wear and bone in your native language? And I don't even want to get into break vs brake. <grin>

Polaris OBark

At least I didn't write ShimaNO.

My native language is FORTRAN.

Iride01 

Well if your native language is FORTRAN, then you should know that you have to declare all user defined types. I didn't see a declaration for those words and their implicit definition didn't match the use so I threw a compiler error.

Polaris OBark

Use the --vomit-frame-pointer compiler directive.

Litespud

who needs breaks when you drope the hamar? 👍

TiHabanero

It is amazing that Fortran is still used, but it surely is.

squirtdad

Heathen, COBOL is the way

Sorcerer

GO1 pads obtain inexpensive obtainableNecessary cooling fins not /maybe 🤔Downhills Clydesdales if not 5+ miles
and drag vertical > 2k /∆ V

Obsolete Package markings
Regardless

Rotors cheap only resin /expensive ice tech

Deform Brake track

Wear premature
springs retaining screeching

Pistons clean

Lube oil mineral with
Worries: none

Much noisy - not


Down pads wearToo late replace beforeOccurs damage rotorLeft none bone

soyabean

Inventory shortages means using whatever you can get your hands on.

A new cheapie pad will be better than end of life premium pads that are grinding a disc metal on metal.

Unlike automotive brakes, they have a wear indicator made of soft metal so you can hear it when it's time.

But on bikes, they need to be visually inspected. When you hear it, it's too late.

Chuck M 

IMHO with you being willing and able to monitor them why not get the maximum life out of them? I do much the same with my vehicle service as it nags me for an oil change at 15% oil life and I will hold off until 5%. That being said, I get that reminder every time I start my engine, something a bike can't do. Also my intention for my disc brake bike was to overhaul it this winter but here it is nearly spring and I haven't taken it off the wall.

Long story short, I need to check my pads this week.

surak

I see 0.5mm in the Shimano dealer's manual for R8050. Also, you can't wear them to the bone because the pad presser springs will start scraping against the rotors. Rotors aren't any easier to source than pads. Don't be penny wise and pound foolish.

soyabean

Not a good analogy since engine oil is already half billion years old.

As long as you keep proper engine oil levels, it's very safe to keep using un-burned oil well beyond maintenance recommendations.

This reminds me of the movie '1984' where Winston kept re-using an end of life shaving blade...

HillRider

Current synthetic oils are a lot newer than that. Also, using oil beyond it's recommended service life is foolish, not because the oil itself is worn out but the additives have been used up, and their protection is not what it should be. Save $40 on an oil change and discard a $40,000 vehicle prematurely?

dedhed

There's a reason for old auto mechanic's adage of, "pay me now or pay me later". Especially in modern high revving IC engines with very close tolerances, aluminium blocks, and variable valve & cam timing.

Koyote

Skipping the oil change almost always means skipping the filter replacement, too -- and that's a problem.

base2 

...or alternatively, skip the oil change & simply replace the filter & top up the oil to the proper level.

It's not like the oil is bad, it's just the impurities have accumulated. Swapping out the impurity collector before it clogs & the safety valve diverts the flow to bypass mode is savvy equipment operation.

It'd be a hard sell for consumer facing enterprises like car dealerships & Jiffy Lube. But the practice is sound for all manner of industrial applications.

veganbikes

Replace pads and rotors as needed no need to wear them out to death. Not going to save you anything and could cost you a lot more.

I am seeing 4 different pads (granted non-finned) that will work for those brakes at 50+ in stock at my distributor (and a few others with lower stock) meaning pretty much any shop can get them and probably some shop already got 'em. They even have some E-bike specific pads from Jagwire which would do the trick and sure maybe you are wearing them down quick and the finned pads are nice but possibly a change in braking and also just a little more replacement would do you just fine. So long as you have good quality pads the fins aren't a deal breaker and when you can get them get them otherwise just stick with one of the G-series or style pads for a bit. Brakes are one of those places on a bike I would try and get the most life out of they are relatively cheap to replace and provide an extremely important service in allowing you to stop and slow down which could save your life.

soyabean

I have friends with M's and AMG's and they synth oil change pretty much every month.

But a grocery getter that's always doing the speed limit, all they need is proper oil level and good SAE oil that isn't pitch black, which takes a lot to get to, and even more so to the point where there are chunks in it. When these vehicles display 0% life on oil yet it's still golden yellow, it's just wasting money and causing more carbon footprint.

Maintenance schedules really helps folks that never look under the hood, so if they are leaking or burning any, it will be caught on the next visit.

dedhed

Stop & go city driving, idling, short hops without running at operating temperatures is more severe duty than running your AMG down the interstate

soyabean

... yet if that oil is still golden yellow, change it anyways, right?

Hey, my friends that own garages and dealerships, trust me are very happy to play that to the clients

Polaris OBark

There is a bone-shaped wear pattern that emerges as you approach the absolute end-point prior to damage (see photos -- same pads, different lighting angles). When I just did this, I changed them as soon as I started hearing a tiny bit of spring rattling noise. I can also tell by how close the brake lever approaches the handlebars. The rotors currently are fine, but I wouldn't have wanted to go any further. The pads are probably within a day or two of doing damage.

XT and Ultegra rotors are a bit easier to get ahold of at the moment, vs. L03A pads FWIW.

surak

Not based off any casual search I've done, and that's also forgetting that there's a 3x price difference between pads vs rotors.

soyabean

Which can be further accelerated on an unexpected surprise on avoiding an accident, ie. bikers in front of you that just decide to stop for no reason, just like on interstates.

That's why you really want to stock up on more pads whenever possible.

Polaris OBark

This is exactly the problem. L03A have been unobtainium for the last year. I do have a stash of J03A (new versions of the ones pictured in the OP), but I want to make those last as long as is reasonable.

I did have a pad trash a new rotor a couple of years ago on another bike while my kid was riding it, so I understand the problem.