Did a wheel circuit flush and so had to remove the front and rear disc pads.
I noticed that on all three pairs of pads the inside pad was more worn than the outside pad.
On one of the front pairs of pads the outside pad had plenty of meat on it but the inside pad was so badly worn that I had to replace the set.
The picture below shows on the left one set of front pads - the outside pad at the top & the inside pad below. Nothing unusual there. On the right however you can see that the outside pad (top) has plenty of meat but the inside pad below has very little - necessitating the replacement of the pair.
Anyone got an explanation for -
1) why in general the inside pads wear more than the outside pads?
2) why on one set the outside pad had plenty of meat left but the inside pad was shot?
60% of the art of conversation is knowing when to say nothing
In the past I've observed the same with my 04 R. Any here with more knowledge please chime in but in my opinion the fault lies in dirt in the caliper assembly. In a clean and properly lubricated assembly the piston applies force to one side of a "floating" assembly. If all is clean then the force is equally distributed between both pads.
Now if I am wrong just blame it on my 15 days in a coma last May.
wayne
The Older I Get, The Less I know. (in honor of MikeCam
'05 RT
'04 R
'03 R
CB750
KZ750
HD 350 Sprint
garr2 wrote:Did a wheel circuit flush and so had to remove the front and rear disc pads.
I noticed that on all three pairs of pads the inside pad was more worn than the outside pad.
On one of the front pairs of pads the outside pad had plenty of meat on it but the inside pad was so badly worn that I had to replace the set.
The picture below shows on the left one set of front pads - the outside pad at the top & the inside pad below. Nothing unusual there. On the right however you can see that the outside pad (top) has plenty of meat but the inside pad below has very little - necessitating the replacement of the pair.
Anyone got an explanation for -
1) why in general the inside pads wear more than the outside pads?
2) why on one set the outside pad had plenty of meat left but the inside pad was shot?
The inside pads are manufactured with less pad thickness than the outside. I have a brand new set of stock (rear pads) here and the inside pad is about 1mm+ thinner in wearable material. That way the inner pad will wear to the (brake pad thickness check) sight hole before the outside pad.
Same thing happened with my front calipers - inside pads worn while outsides were still half good.
Calipers seems to slide smoothly on the pins, and our calipers use four fluid-pressurized pistons so they really shouldn't need to slide much to equalize pad pressure on the inside and outside - the fluid should do that...
My right disc has a little bit of runout (warpage) but not bad, and has been there since I bought the bike 6 years ago. Interestingly, the right inside pad was thinner than the left inside pad by maybe .5 mm.
I blow the dust out of the calipers when they start to squeal (about every month), so there should never be a lot of dirt in them.
Sunbeemer wrote:Same thing happened with my front calipers - inside pads worn while outsides were still half good.
Calipers seems to slide smoothly on the pins, and our calipers use four fluid-pressurized pistons so they really shouldn't need to slide much to equalize pad pressure on the inside and outside - the fluid should do that...
My right disc has a little bit of runout (warpage) but not bad, and has been there since I bought the bike 6 years ago. Interestingly, the right inside pad was thinner than the left inside pad by maybe .5 mm.
I blow the dust out of the calipers when they start to squeal (about every month), so there should never be a lot of dirt in them.
Hopefully someone knows...
Reading the last post may put your mind at ease. The pads for the R1150RX are created (inside Vs outside) unequally for a reason.
Reading the last post may put your mind at ease. The pads for the R1150RX are created (inside Vs outside) unequally for a reason.
When you buy a pair of rear pads you can see that they were indeed created different (to each other). One (inside) is thinner than the other and the backing plates are asymmetrical mirror images of each other. This means that the thinner inside pad can only be fitted on the inside. So the back pads may very well be made in this way for the reason you give.
The front pads however are different - not compared to each other but compared to the back.
A set of new front pads are exactly the same as each other - same thickness friction material, identical symmetrical backing plate. This means that there is no inside pad or outside pad - each pad will fit on the inside or the outside .
And so - for the front pads at least - the mystery of the faster wearing inside pad remains just that : a mystery
60% of the art of conversation is knowing when to say nothing
Thanks...I stand happily corrected, as (based on your scribe) I can now switch my inside pads to the outside, and vice versa, on the front calipers and run more miles on the front pads. This is good news for us frugal folk...thanks again.
I'm especially frugal (sounds so much more professional than "tight as hell") so I solved my premature brake pad wear by simply dragging my feet in stops. Also helps keep my feet warm in the winter. It does seem to be hell on my boots though.
The Older I Get, The Less I know. (in honor of MikeCam
'05 RT
'04 R
'03 R
CB750
KZ750
HD 350 Sprint
towerworker wrote:I'm especially frugal (sounds so much more professional than "tight as hell") so I solved my premature brake pad wear by simply dragging my feet in stops. Also helps keep my feet warm in the winter. It does seem to be hell on my boots though.
The pads are of different thickness is a fact, but applying low pressure to the brakes will tend to cause the inner ( piston side) to wear more then the outboard pad and combine this with thinner pads already and you have what you see in the photos ( nice photos by the way!). This is due to friction of dirt, dust and corrosion that builds up on the caliper slides hold the caliper assembly with enough friction to cause the inboard pad to contact the rotor but not the outboard pad.. In a perfect world, the caliper clamps both pads with equal force, and that happens for the most part on normal to hard applications. Its those foot dragging the rear brake times that kill the rear pads quickly. Not to mention allot of folks do not apply enough front brake when stopping.
Thanks...I stand happily corrected, as (based on your scribe) I can now switch my inside pads to the outside, and vice versa, on the front calipers and run more miles on the front pads. This is good news for us frugal folk...thanks again.
Is there any reason why you couldn't just reverse the pads on the calliper that has very uneven wear (eg the right hand pair above) as ebincia suggested?
Clymer rather than being frugal says that both pairs of front disc pads should be replaced at once - which means that if 1 out of 4 front disc pads is worn all 4 should be replaced at the same time.
Any thoughts?
60% of the art of conversation is knowing when to say nothing
Is there any reason why you couldn't just reverse the pads on the calliper that has very uneven wear (eg the right hand pair above) as ebincia suggested?
I'd be reluctant to do this for the same reason that new pads need to be broken in during the first couple of hundred miles. If you look closely at any used pad you'll notice it has a set of grooves in it caused by rubbing against a conversely grooved rotor. If you remount that pad on another rotor, it wouldn't contact the rotor anywhere but on the highspots until, after many miles, it wore into the grooves of that rotor. This would take even longer than a new, flat pad would, since the old high spots must wear off before it can start wearing into the different rotor's grooves. Meanwhile, your braking force would be decreased by the lesser amount of surface area contacting the rotor.
Of course if your rotors are perfectly flat and the old pads likewise perfectly flat, this problem diminishes, but is that a realistic expectation?
Remember, these are your brakes...you may need them to save your life. How much is that worth to you and your loved ones?
