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Brake pad age

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My 1981 650GL front brake pads have plenty of material left on them. However, they date back to at least 1993. I sanded the face of the pads before I reinstalled them, and they do stop the bike. However, do pads go bad with age? Should I be looking at new pads even though these look fine and have alot of life left in them?
 
As someone who spent 5 years compounding friction and 25 years vehicle testing the product, no the friction does not degrade like a tire.

Brake effectiveness is all dependent on the carbonization of the friction material compound at the rubbing surface and the deposited transfer layer (which should only be a few molecules thick) on the rotor or drum. Vehicles sitting overnight have to regenerate both of those surfaces in order to have optimum friction.

The terms of hard and soft friction goes back a long time and anyone who works in the friction industry cringes when they hear the term. The terms used for the coefficient or wear properties are not related. You can have a higher compressible friction material that can have higher or lower opposing surface wear, or higher or lower coefficient of friction. It's often misused in the enthusiast community.
 
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Not sue why, but 30 year old pads don't stop as good as new ones. The difference is night and day.
 
tkent02 said:
Not sue why, but 30 year old pads don't stop as good as new ones. The difference is night and day.
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This is what I've found as well.

Let's not get too sciency here... all that fancy talk of coefficients and suchlike is making me all woozy and faint.

Or put this another way: brake pads (and tires) are a lot better now than they used to be. Might as well take advantage of the benefits of modern compounds.

Plus, you don't know where those old pads have been. If someone fixed a fork oil leak a long time ago but didn't change the pads, the pads could still be pretty slick. No matter what I've tried, brake pads never seem to be the same once they've been contaminated with fork oil or brake fluid.


But yeah, all else being equal (which it never is) brake pads don't really degrade over time. I have found original drum brake shoes a couple of times that have lost their friction surfaces because the adhesive used to stick them to the body of the brake deteriorated. I've never seen this with disk brake pads, but I suppose it's possible.

If they work, use 'em.
 
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Drum lining segments are bonded to shoes in a totally different method and adhesive. Lining segments are first fully cured then bonded post bake. The typical reason the segments debond is due to iron oxide formation on the shoes surface table, typically called rust jacking. Tractor trailer and transit vehicles are the most prone due to either sitting times or the daily washes. Of course if the steel is not prepped correctly or the wrong adhesive chosen you got production issues.

Disc pads are moulded onto the steel backs during the initial pressing or during the high pressure forming. The bonding resin is similar in chemistry to the resin that bonds the 15 to 20 components making up a friction material.

It is not uncommon in our industry to do what our company did, store examples of our products for five/ten year retest for aging, both inside building and in outside storage builds so the product would go through temp and humidity changes. Some products were tested well after a compounder would retire so he never knew how his/her brainchild did. Not that all those products would be around for a recall, but it helps the compounders to understand their recipes. It takes about 10 years for a compounder to get to be good, which is why friction material compounding is called a black art. It's not just learning the synergy of the formulation components, but what they turn into when they are carbonized at the friction material rubbing surface.
 
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I just ordered a pair of EBC Organic Kevlar pads. I was leaning toward sintered but, after reading about it on this forum, went with the other.
 
Sintered is a real high temp compound. Not so good cool. You need to be a track or canyon running to get the best out of them.
 
Skinner said:
I just ordered a pair of EBC Organic Kevlar pads. I was leaning toward sintered but, after reading about it on this forum, went with the other.
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Excellent choice. You'll love 'em. :D
 
TooManyToys said:
Tractor trailer and transit vehicles are the most prone due to either sitting times or the daily washes.
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Says who exactly? Truck brake shoes have been riveted for at least the past 30 years probably more. How many busses do you know that sit for years on end?
 
I installed the new EBC pads last night and went for a test drive. All I can say is WOW! What a difference. With the old pads I could stop but never felt comfortable when thinking about an emergency stop. The new pads changed all that.
 
jbthomp said:
Says who exactly? Truck brake shoes have been riveted for at least the past 30 years probably more. How many busses do you know that sit for years on end?
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Well, me for one. My 30 year career was in R&D for one of the worlds largest friction material suppliers known as Abex/Federal-Mogul/Ferodo/Wagner.

It doesn't matter if the friction is bonded or riveted, pad or shoe. Rust jacking will start with a vehicle sitting as short as overnight if the shoe or steel back surface abutting the friction has a compromised rust protection coating. A week or two can be a easy issue.

While trailers can sit on the back lot for some time, with transit the issue is mostly initiated with the daily or weekly washing process when surfactants and other washing compounds work their way into the boundary area. Since there are people here not as experienced as you with commercial air brake, is rare to have a backing plate with air drum brakes so the shoes and drums interior surfaces are open making it easy for contamination.

Rust jacking has been a long standing issue and you can see how prevalent along with the attempts in preventing it by Googling: rust jacking brake shoes

Going to images you will see not only brake shoe issues but pads as well. Tack on SAE Truck and Bus and you can see some of the technical papers some of us have written over the years. The new de-icers used on the roadways over the last decade has raised the issue and costs compared to where we were 20 years ago.
 
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Skinner said:
I just ordered a pair of EBC Organic Kevlar pads. I was leaning toward sintered but, after reading about it on this forum, went with the other.
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I agree, good choice.

I made the mistake of buying sintered pads for my 700ES many years ago. Scored the Hell out of the front rotors quickly. I replaced them with organic ones long before they were worn out to prevent further damage to my rotors. I got the rotors refaced at a machine shop for $30, and they've been on since, with no further wear.

Because I've owned and flipped so many bikes over the years, I've tried many different pad brands and materials. I've decided that I like the EBC organic Kevlar pads best, and that's pretty much all I buy now.
 
that's really interesting,TooManyToys...I have wondered.....and again those d*mned de-icers! Just googling it brings up crazy stuff, like old fracking mixes sprayed on the roads
 
Truckers have been really hammered with corrosion issues not only with the body work but electrical as well. I've got pictures of brake pads and rotors that have eroded away. And they wonder why our bridges are in such bad shape and running out of money to fix them.
 
TooManyToys said:
Truckers have been really hammered with corrosion issues not only with the body work but electrical as well. I've got pictures of brake pads and rotors that have eroded away. And they wonder why our bridges are in such bad shape and running out of money to fix them.
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Not just truckers - my '79 calipers were rotten internally and I put that down to the crap design, trapping road muck, salt, and likely de-icer too, from what you say. One look at them convinced me to toss them aside.
 
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