Chainslinger

I just got a new mail order bike with disc brakes which are new to me and while trying to set them up with a pad alignment tool I touched the rotors several times with my bare hands not realizing how much of a no no that is. I thought I had them working well on the stand but then I took the bike for a short test run in my culdesac and there's basically no stopping power at all.

I haven't tried bedding them in yet but they should have at least some effectiveness at this stage shouldn't they? Can the skin oil residue I left on the rotors be causing that? If I wipe them down with isopropyl will that make them ready enough to start the bedding process or do I need to clean or replace the pads now also?

redlude97

its fine, you want to avoid grease and brake fluid contamination but a bit of skin oil transfer while not ideal is not an issue. the bed in is key to stopping power and setup.

dsbrantjr

Cleaning the rotors, and pads for that matter, will do no harm and might be beneficial, so why not?.

TimothyH

Touching pads with your fingers isn't a big deal as long as your hands are clean, not greasy. Just try not to.

You don't want to touch metallic/sintered pads because the metal fibers can get into your skin like fiberglass insulation or wood splinters.

jimc101

Go on, which brand of Sintered pad has loose fibers like fiberglass, having used Sintered pads for many years now, have never had an when handling them

TimothyH

"Lose fibers like fiberglass" are your words. Those are not my words.

I said "metal fibers can get into your skin."

Run your hand over a semi-metallic automobile brake pad. You won't do it a second time. Sintered bike brake pads differ only in size.


-Tim-

Canker

Bedding in disc brakes is way over hyped. If your brakes are crap right out of the box bedding them in isn't going to make them awesome, they will still be crap. Yes you should do it but almost nobody does in the real world, cars, and your brakes will be fine if you don't.

We need more info. Are you running hydro or cable brakes? How much slop/spongyness do you have in the levers? If your brakes are crappy it is either a setup issue, they need bleed, or they got contaminated and no touching the rotor shouldn't be enough to do that.

redlude97

YMMV, but all of my disc brakes, bike and car get better and are less likely to vibrate or squeel after a proper brake in, both mechanical and hydro, resin or sintered.

Slightspeed

Clean the rotors with rubbing alcohol. Remove the pads and lightly sand them on a flat block with medium to fine sandpaper. Don't touch any braking surface with your fingers. Reassemble, adjust if necessary, go for a ride. I have cable operated TRP Spyres which occasionally squeal, but they do stop well, even better with clean dry braking surfaces.