epnnf

you know how disc brakes work great when the pads are new, then slowly fade, then it's so bad you have to replace the pads? I replaced the pads today, but the old pads still had plenty of material left! I even tried an experiment: on the old pads, roughened up the surface a little with a file > reinstall > no difference. Install new pads > work great. My ?- why are they designed like this? It's wasted pad material. Can anything be done to make then work effectively longer?

AEO

did you get any oil or lube on it by accident?

well biked

I don't know what disc brake you have, but I often have customers come in our shop and wonder why their Avid mechanicals aren't performing well despite a fairly recent pad change, and all we have to do is turn the adjustment knob(s) a bit and the brakes work great. On these brakes, the adjustment knobs are there partly to allow you to adjust for pad wear (i.e., maintain the same braking performance as the pads wear).

Drop2Flat

It's quite possible that your previous pads got contaminated, which means that you would have to replace them before they got fully worn out. Another concern is that if the pads were contaminated then your rotor might be as well. It's always a good idea when replacing pads to fully clean the rotor with a dry degreaser so as to avoid contaminating the next set of pads. Also, look around the caliper for any brake fluid that may be leaking out which could potentially get on the pads. What I've also found is that suspension forks, if you have one, can leak fluid if they haven't been serviced in a while, so it's a good idea to check the lowers for leaks.

epnnf

sorry, I should' ve included more details:

2008 C'dale Bad Boy disc
Avid BB5 pads (the round ones)
mechanical (cable)
I wipe down/blow off the pads/caliper when I change pads- no lube/oil around
I'm familiar with the adjustment knob issue- check
I frequently clean the rotors w/those alcohol pad thingies- similar to the ones they use b4 they give you a shot in the arm

So, why is there so much unused pad material left?

pwdeegan

happens to me, too (BB7s). i wonder if it's because the used pads have absorbed oil from regular riding on the road (well, i ride in a lot of rain, so i'm thinking about road spray). i've cleaned my pads with brake cleaner, roughened them, used compressed air (at different times on different pads to see if one worked better than another) all without great effect. It helps for the first 3-4 pulls. If i put new pads in, then everything is super sharp for a month or so, then it's back to still-better-than-every-other-brake, but no longer this-thing-can-stop-on-a-hair performance.

clearly in my case the difference is not anything vital or related to safety; it's solely the difference between that new sticky feel and something that just works really well if still slightly less sticky.

but you're right; by the time i replace the pads (about 9-12 months) there is still about half the material left on the pads. so again, i wonder if the remaining half has just been contaminated by regular wear and tear. i chalk it up to the cost of existence, and know that i could ride further on the old pads, but i don't need to.

wunderkind

Are they just glazed? If so, just run the pads on some sand paper.