Issue .. or... no?

[cruzer1800]

I usually bounce things like this off Larry but alas, he is in for maintenance currently. Any other brake pad experts out there, would appreciate a quick help..
New pads installed about 2,500 mi ago. Replacing rear tire (expensive large nail, sooo nice) just checking wear and saw this. Could be totally normal or (learning from Yoda/Larry) might indicate an alignment issue or something else I am not aware of. Im working on my apprentice ST1300 maintenance badge but SOOOO much to learn...
Hey, I pulled the rear wheel off like a pro this time! 10 min tops, yay me!
Rear pads, ST1300
Notice wear spots on bottom right square, and top left... If this is an issue, please recommend how to correct it. To me... looks like they should be wearing EVENLY and obviously are NOT.
Any advice much appreciated!

 

[Gus1300]

My first question would be, were all the surfaces flat when new or were some of the edges/corners lower than the rest of the material to the point where they haven't reached the brake disc yet? It looks like a few more than the ones you mentioned still have some 'new' area on them. It does look like there is more brake dust present at the bottom (in pic) of the left pad than the right (again, in pic, but if I'm orienting myself correctly, the left pad is on the left in the pic, and the pin side at the bottom is the top of the pad as installed). I'm sure someone will correct that if I'm mistaken!

The wear doesn't look that uneven to me but I'm sure smarter individuals will be able to give a more specific answer. (and I'll be watching to see what they say!) But I am curious about what's causing the 'gouge' on the left pad about 1/4 of the way from the 'inside' (in pic) across all 4 surfaces. Have you found anything on that side of the disc?

 

[Mellow]

If you're worried about it I would clean the caliper pistons and sliders. But, it will take a while for them to wear more even.

 

[SMSW]

Most brake problems are the result of deferred maintenance and/or improper maintenance. First, what year bike is this, how many miles on the clock, how long have you owned the bike? When you pulled the old pads, did you examine them for abnormal wear? If your bike is older and has an uncertain history (i.e. no maintenance records from the PO showing when and what he did) did you to a thorough service - clean and examine calipers, mounting hardware and assemble everything according to the Honda Service Manual?

The caliper bracket's stopper pin hole is known to wear showing spiral marks on older bikes (read @Igofar's comments in some of the older threads on brakes) and Larry has posted pictures of wear on the pockets that hold the pads. I'm not saying those contributed to your problems, but as our bikes age, we should all be looking for unusual signs of wear.

 

[dduelin]

Disc brakes with one set of pistons (not opposed pistons in each half of the caliper) rarely wear exactly evenly. The leading edge of one pad and the trailing edge of the other often "mirror" each other across the life of the pads. Worry less, ride more.

 

[Sadlsor]

I'll just say, the leading edge(-s) of pads would be expected to wear more than the other end, it seems to me.
In other words, the first surface to contact the rolling / spinning rotor will take the brunt of the stopping power, in this case the rearmost pad surfaces, or the bottom ones in the photo.
Even though multiple pistons and the slider pin all serve to move the assembly in and out, they don't always move with absolute precision, and my car and bike pads have always shown a "tapered" wear pattern, to some degree -- especially visible when nearing their end of life.
Even if I'm correct, the corners don't appear normal... but also in the picture I can't really tell the remaining pad life, and it would be good to know the actual mileage on this set of pads.

 

[diferg]

+1 post #5

 

[cruzer1800]

I'll just say, the leading edge(-s) of pads would be expected to wear more than the other end, it seems to me.
In other words, the first surface to contact the rolling / spinning rotor will take the brunt of the stopping power, in this case the rearmost pad surfaces, or the bottom ones in the photo.
Even though multiple pistons and the slider pin all serve to move the assembly in and out, they don't always move with absolute precision, and my car and bike pads have always shown a "tapered" wear pattern, to some degree -- especially visible when nearing their end of life.
Even if I'm correct, the corners don't appear normal... but also in the picture I can't really tell the remaining pad life, and it would be good to know the actual mileage on this set of pads.

Correction to my original post... I installed these new "1,500ish" miles ago. Checked my records to clarify

 

[cruzer1800]

Disc brakes with one set of pistons (not opposed pistons in each half of the caliper) rarely wear exactly evenly. The leading edge of one pad and the trailing edge of the other often "mirror" each other across the life of the pads. Worry less, ride more.

Love that advice!!

 

[Andrew Shadow]

I have never checked new Honda ST1300 brake pads, but I doubt that they are any different than any other brake pads. Brake pads appear to be very flat and uniform when given a cursory look, but they are rarely perfectly flat and even across their entire surface, especially if they are segmented pads. They are not manufactured to the same tolerances as a machined surface, there simply is no need for that level of perfection in this wear surface. If you were to rub new brake pads on sand paper laying on a perfectly flat surface you would find that there are high and low spots on most of them. This is part of why there is a break-in, or wear-in, period for new brake pads. 1,500 miles is not long enough to determine if this is just normal wear-in or there is a problem. Ride more and check again later.

Disc brakes with one set of pistons (not opposed pistons in each half of the caliper) rarely wear exactly evenly. The leading edge of one pad and the trailing edge of the other often "mirror" each other across the life of the pads. Worry less, ride more.

Spot-on.
With the caveat that if the difference remains minor and is also fairly consistent between the pads on both sides of the same disc, I agree with Dave-

Worry less, ride more.

There is a huge amount of force transferred from the rotating disc to the caliper through the brake pads when the brakes are applied. The force of the rotating disc drags the brake pads, and therefore the caliper, in the same direction as it rotates until the limit of the caliper movement in that direction is reached. Since a floating caliper is not rigidly mounted, there is always a little bit of play in the mounted caliper. Because the force is not being applied in the centre of the caliper, this force leverages the calipers to rotate off centre very slightly. It is impossible to prevent this with a floating caliper system. This results in the leading edge of the brake pads wearing a little more than the trailing edge. This is why brake pad squealers were always installed on the leading edge of the brake pad, because the leading edge wears first.

 

[cruzer1800]

I have never checked new Honda ST1300 brake pads, but I doubt that they are any different than any other brake pads. Brake pads appear to be very flat and uniform when given a cursory look, but they are rarely perfectly flat and even across their entire surface, especially if they are segmented pads. They are not manufactured to the same tolerances as a machined surface, there simply is no need for that level of perfection in this wear surface. If you were to rub new brake pads on sand paper laying on a perfectly flat surface you would find that there are high and low spots on most of them. This is part of why there is a break-in, or wear-in, period for new brake pads. 1,500 miles is not long enough to determine if this is just normal wear-in or there is a problem. Ride more and check again later.

Spot-on.
With the caveat that if the difference remains minor and is also fairly consistent between the pads on both sides of the same disc, I agree with Dave-
There is a huge amount of force transferred from the rotating disc to the caliper through the brake pads when the brakes are applied. The force of the rotating disc drags the brake pads, and therefore the caliper, in the same direction as it rotates until the limit of the caliper movement in that direction is reached. Since a floating caliper is not rigidly mounted, there is always a little bit of play in the mounted caliper. Because the force is not being applied in the centre of the caliper, this force leverages the calipers to rotate off centre very slightly. It is impossible to prevent this with a floating caliper system. This results in the leading edge of the brake pads wearing a little more than the trailing edge. This is why brake pad squealers were always installed on the leading edge of the brake pad, because the leading edge wears first.

Wow.. you guys are amazing... i have SOOO much to learn. THANK YOU!

 

[Andrew Shadow]

I usually bounce things like this off Larry but alas, he is in for maintenance currently. Any other brake pad experts out there, would appreciate a quick help..
New pads installed about 2,500 mi ago. Replacing rear tire (expensive large nail, sooo nice) just checking wear and saw this. Could be totally normal or (learning from Yoda/Larry) might indicate an alignment issue or something else I am not aware of. Im working on my apprentice ST1300 maintenance badge but SOOOO much to learn...
Hey, I pulled the rear wheel off like a pro this time! 10 min tops, yay me!
Rear pads, ST1300
Notice wear spots on bottom right square, and top left... If this is an issue, please recommend how to correct it. To me... looks like they should be wearing EVENLY and obviously are NOT.
Any advice much appreciated!

I meant to link to the below article when I responded yesterday and forgot, so here it is now.

A common cause of uneven wear of newly installed brake pads is improper installation of the spring clips that hold the pads in place in the caliper, or improper installation of the pads in to those clips. Since you replaced the brake pads only 1,500 miles ago, it might be worth having a look to make sure that the brake pad clips and the pads are installed correctly and are not causing uneven wear.

The below article explains and illustrates it well. It will also give you an idea of what else to have a look at since you will be looking anyway.
ST1300 Maintenance - Brakes- Avoiding the Pitfalls

 

[Al st1100]

what did the old pads look like? Were they worn even or at least fairly even.

 

[motornut]

The reason for multiple pads are exactly what is said earlier, to clarify-the leading edge is what does the most braking when applied. On performance bikes that translates to quicker and more aggressive braking ie braking late for corners.
I have a Kawasaki Concours that uses multiple pads and a ST that uses fewer pads, the difference for me is minimal if I notice at all. Most people aren't that good. Myself included ------ definitely. My thing about this is cost. Multiple pads cost a bunch more ( 56 vs 71 for OEM)
This is a similar thing with inverted forks, they are used for lower unsprung weight, most of us don't need it but it sounds good on paper and impresses the kids.
My reason for the Concours comes in at about 140 miles an hour, no I don't need that kind of speed. But the acceleration is awesome and I only have done this when I can see a long way ahead and there is nobody around. Those other occupants on the road come up too fast and I am never sure what the are going to do. Plus it was 2 years old with 2 miles on it so I got it cheap.
The brake pads that you took picture of look just like the ones I have taken off my Connie. Yours are fine.
I have found the brakes on the ST not needing multiple pads for performance that I personally can't use.
Although Brakes and Steering---everything else is optional. So I will not criticize any one for going further than I chose to, I am not riding your bike ---you are. I am giving my !opinion only! as to what to use.

 

[cruzer1800]

what did the old pads look like? Were they worn even or at least fairly even.

Fairly even.. rears were worn out, fronts still had about 80% left... SMC was locked up as bike evidently was parked over 10 years when I got it. (Estimated by date code on tires and the fact that they were practically NEW condition when I got it in 2022) First thing I did was get with Larry who walked me through renewing the entire brake system front to rear. And new tires. =)

 

[cruzer1800]

I meant to link to the below article when I responded yesterday and forgot, so here it is now.

A common cause of uneven wear of newly installed brake pads is improper installation of the spring clips that hold the pads in place in the caliper, or improper installation of the pads in to those clips. Since you replaced the brake pads only 1,500 miles ago, it might be worth having a look to make sure that the brake pad clips and the pads are installed correctly and are not causing uneven wear.

The below article explains and illustrates it well. It will also give you an idea of what else to have a look at since you will be looking anyway.
ST1300 Maintenance - Brakes- Avoiding the Pitfalls

EXCELLENT! Thanks so much!