This is a controversial topic on here, and I just thought I’d relate an experience from today.

Built up a new frame, had to shorten the hoses and on the test ride the brake were awful. Tried a solvent or two and some soap and water to no avail, so I resolved to clean the pads as best I could. Good scrub with washing up.liquid then I burned them in the gas flame. Properly clean.

But.. Put them back on and they are rubbish. Severe power loss, and interestingly no sound, no rubbing noise when I applied them.

So I did a couple of heavy stops going down hill and they started to return to normal, plenty of power and the rubbing sound on application came back.

So, given that they were completely clean to start with, this adds weight to the idea that pad material needs to be deposited on the disc.

I don’t think its the pad material being transferred more that the pad surface gets a much closer working tolerance to the face of the disc (ridges and lumpy) then works better. I reckon on 10 really hard stops to bed a set it in.

So, given that they were completely clean to start with, this adds weight to the idea that pad material needs to be deposited on the disc.

Or, the pads need to be matched to the surface of the rotor to provide maximum interference. I don’t see how the pad ‘deposits’ material on the rotor.

These were the same pads in the same positions on the same rotors. I didn’t sand them off or antyhing.

What’s weird is the massive difference in power. I’m not talking about just getting a bit sharper, I’m talking about dangerously not slowing down at all to working fine. I’ve had mismatched reused old messed up pads before and they’ve always worked just a bit less well – never like this.

Anyone have access to an electron microscope?

Magura recommend 20-30 sharp stops from a fair lick to bed their pads in. It makes a helluva difference.

Yes, some of the pad material transfers/smears onto the disc.

See here

Hmm, now they squeal like a mofo when wet.. Never used to. Still, hoping a real ride will sort them out.

Pad material tranferrance onto the disc is well known in cars etc, why would it be any different to bikes?
Obviously with new dics / pads then there is also the task of conforming the pads to the disc surface, but this had already been done in Mogrips case.
If bedding in is a myth, why do you notice a reduction in initial power when you put new pads? Then after a few hard stops the power returns?

I dont understand why people still argue that bedding in is unnecessary when science can prove that it is.

Yep, any decent car garage will offer advice on bedding in car brakes if they fit pads/discs – usually along the lines of ‘no sharp stops or big motorway braking for first 100 miles or so plz or you iz squealing’ which is a little at odds with recieved wisdom on MTB brakes but certainly in the same ballpark. I’m not sure this even needs questioning anymore. Put it in the same box as not using DOT fluid that’s been open for any length of time unless you like lowering the boiling point.

Coke works for me. New pads.fit them..pour coke on them ( the sugary beverage not the sugary looking drug!) go for a ride…cant remember where I read it but works for me.

I dont understand why people still argue that bedding in is unnecessary when science can prove that it is.

Do people actually still argue this?. Thought it was a given.

This IS STW remember. Some people would argue black is white if they could!

…cant remember where I read it but works for me.

Maybe in a dream?

😉

Nobeerinthefridge – Member

Do people actually still argue this?. Thought it was a given.

i’d argue that:

yes, new brakes may need a little use before they’re working at their best. But they don’t need special treatment.

(mind you, i do live at the top of a massive hill, maybe it’s got the perfect combination of contours and corners for bedding-in brakes)

Just take them for a ride down the Trans Pennine Trail, although they might just go from “bedded in” to “nothing left” after 40km!!

Forgot how gritty it was down there. Very much like riding at Kielder in the wet!! 😯

Rarely bother these days. Just ride mince around for a few miles & they work Ok for me

I’ve a big hill I ride down pulsing the brakes to bed in pads, about half way down they go from almost not braking to lock up. It’s important on to drag them though, on & off is best

Coke works for me. New pads.fit them..pour coke on them ( the sugary beverage not the sugary looking drug!) go for a ride…cant remember where I read it but works for me.

Probably does as diet coke removes oils stains from concrete a treat

What about the oft-quoted idea that they’ll wear away quickly if you don’t bed them in then?