big chainring 

I just recently replaced the original pads on some brakes from the 1960's. So once every 50years is about right.

CliffordK

How worn were your brakes when you replaced them?

I wear mine right down to the wear line, or to the external brake pad holders.

No need to replace half-worn pads.

bikebikebike

I have several older bikes,. 20+ years. Low use, well cared for. The pads are originals with little rim wear.
The pads are all rock hard, but the bikes stop well enough to satisfy me. No grinding, no scoring.
Again , I have a distorted view because I have rarely had a new full size upright with rim brakes that was less than 10 years old and didn't have rock hard pads.
How long should one go before replacing the pads just for age?
? should I go all Mr. Whipple and unwrap bike shop pads, or pull them off a friend's new bike when he isn't looking and "Squeeze the Charmin?"
to see if it is softer?
Is there a Rockwell Hardness test for pads? and would that mean anything?
All of the discussions appear to be about wear, and to be honest, I have never had to replace for wear, only for deterioration, noise or collections of shmutz.
Most new pads seem to be almost as hard as the ones I have.

Second question, Other than post differences, how interchangeable are rim brake pad styles?
Is there a conversion/comparability chart that I have missed? eg are shimano M50T's replaceable with other styles. I would like all my bikes to use the same pads , if possible.
Hopefully this is not a dumb question, but to be honest , I haven't even found dumb answers anywhere, nor have I not found a discussion of differing brake pad dimensions.
Yet.

shelbyfv

Question #2 - Those Shimano M50T seem to be one piece brake blocks. I would replace those with something like this https://www.amazon.com/SHIMANO-BR-67...J9A08RHRQQE9JE so that the pads are easily swapped. The Kool Stop salmon pads are thought to be softer than some. I don't know but I like and use them. Shimano pads are pretty drama free as well.

WizardOfBoz

Heed the Gremlin:
Probably longer than 700 miles, but if you ride in wet, dirty, or gritty conditions with lots of hills and stop signs and such maybe that's reasonable. Current Schwinn bikes seem to vary in quality, and so you may have brake shoes with the wear-life of manchego cheese. The LBS probably is replacing those shoes with something a bit better, so you'll be able to see how the new pair does.

But in any case use your front brake (practice a bit before you use the front brake to stop you at the stop sign at the bottom of that two-mile, 15% grade hill, though - no sense in experiencing that "over the handle-bars", "experiment in bike-powered human flight" moment).

Also, check your tires. The best tire should be on the front (I rotate the older front tire to the back when I replace the front tire*).

*Never, ever take a more worn tire from the back wheel and rotate it to the front "to even out wear". Putting a new tire on the front and the slightly worn front tire on the rear wheel is fine. But the front tire should always be your best tire. One reason: that's the wheel you should be braking with mostly!

Bike Gremlin

Wrote here in more detail on proper bicycle braking technique.

GamblerGORD53

My SA XL-FDD dyno DRUM brake has 25,000 miles.
I bought it 4 years before this 4 year old thread started.

79pmooney

Clifford, you do live in lava country, Lava dust is incredibly abrasive; We northwesterners regularly wear out rims and brake pads at rates that we are almost as often told are impossible. In my commuting days, I could not get two winters out of my rims (riding 2-3 times/week). I've worn tubular rims clear through the brake track, had a clincher sidewall blow off in the garage while I was in the house. (Sounded lie a gunshot.) Tossed many Open Pro/Sport rims with deep concaves, otherwise perfect.

I don't know the numbers, but from my listening to the geologist at the Cycle Oregon rides and observing, I'd guess that roughly 90% of Oregon is covered with lava of many different eras, types and depths.

I'm guessing the OP doesn't have our dust (the NY of NYSteve suggests a further east location) but he does most of his riding on the same trails. It might be that they have an unusually abrasive dust. But I will comment that I have found rear brakes to have often more wear than fronts, even using the front a lot more. I've attributed this to 1) the rear sees a far dirtier environment and 2) rear brakes get dragged, not squeezed firmly

Edit: I plead guilty of answering a 4 year old post. "No, your honor, no excuse. Just forgot to look at the date."

Ben

bikebikebike

Excellent
Moto's give you an good appreciation of the front brake's dynamics
Bikes are short and forward weighted, love to endo.
Thanks for the heads up on interchangeability of pad systems. I have multiple bikes and will see how hey set up. Again , nice to have fewer systems on the bikes.

Drew Eckhardt 

On December 26th, 2019 they reached 28,034 miles and still have life left.

Andrew R Stewart 

I rode (possibly for the last time (as the replacement is waiting for a painter) my commuter today. It has Mathouser pads installed maybe 15 years ago, when this frame was new. The pads still have lost of like in them and whoever buys the Campy side pulls that they are attached to will be happy for quite a lot more miles. Andy (who likely only has around 20K on this bike)

ChrisAlbertson

As it turns out brake pads made with softer rubber will stop the bike quicker. But they also wear out faster. Just think how long stainless steel pads would last. You would never stop but the pads would outlast five bikes. Tires are the same way. Very grippy tires don't last as long. But tires made for high mileage use harder rubber that does not grip as well.

Your weight does matter. It takes twice as much work (work is force multiplied by distance) to stop a 250-pound river then a 125-pound rider. I'd expect the heavier rider to use up the pads twice as quickly.

Retro Grouch 

750 miles is not very many. Honestly, I kind of doubt your excessive wear is due to using your rear brake excessively. I'm wondering if your rear brake has been dragging all this time. I personally think that's a much more likely scenario.

Were both brake pads evenly worn or only one side? On a properly set up brake, both sides will wear pretty evenly. A dragging brake is much more likely to wear on only one side.

cyccommute 

As loathe as I am to contribute to a 4 year old post, the article linked to by Bike Gremlin, the article is not so excellent in my opinion. There’s several things wrong with it. This, for example, is one of the more glaring errors

If the rear wheel starts to slide, the proper action is to get it to stop sliding, especially if the wheel is sliding out of line. A sliding tire has zero control and zero predictability. A rolling tire can be controlled and will help with steering...even the rear wheel. The proper action is to get the rear wheel back down on the ground by releasing the front brake. At the very least reduce pressure on the front brake. The reason the rear wheel is sliding is because the weight has transferred to the front wheel and the only way to get the rear wheel back on the ground is to move the weight rearward but easing up on the front brake.

Additionally, front tires don’t “slide”. We can’t generate enough friction to slide the front wheel. If the front wheel locks, the rider is headed over the bars. Bikes aren’t “short and front loaded”. They are short and high loaded. In other words, the center of gravity is very high for a short vehicle. The center of gravity is 4 to 5 feet (1.2 to 1.75 meters) off the ground. No other vehicle has such a high center of gravity. Motorcycles, cars, trucks, busses, etc. all have centers of gravity that are between the wheels and near the ground. They can generate enough friction on the road to slide the front wheels without having the rear end go over the front. Motorcycles get close but not as bad as bicycles.

Relying on one brake over the other is improper technic. By learning how to use both brakes effectively, a bicyclist will end up with better control and safer stopping.

bikebikebike

Totally agree on all points.
May be an old thread but a timeless one.

Part of the two wheel challenge is how short the decision time is. Two wheelers often end up doing the luge before they know what's happened.
Unless one has the equivalent of MSF and licensing, I doubt many will get much of a chance to even think about braking.
Pad wear is an opportunity to think for a moment about what is going on, in the first place.
Makes me wonder how light you can make ABS. :-)