This is a continuation of my story about trying out
SRAM's sintered metal brake pads.
For information on the types of SRAM disc brake pads
（→here）,
and on the break-in of sintered pads
（→here）, please check those out.
Right after the sintered pads finished bedding in,
with the pad lightly rubbing the rotor
and the brake lever slightly pulled,
there was a small フ～ン sound on first contact, but
after using them for a while, the depth at which that sound occurs
shifted slightly deeper.
With a very light touch there's no sound,
and pulling a bit more creates a smallフ～ンat a certain point.
When squeezing the brake lever firmly—
not an emergency stop, mind you,
but normal riding—
even passing through theフ～ンzone, there's no noise.
With the bike stationary, pulling the lever to the depth
where that sound occurs and rotating the front wheel backward
reproduces the sound 100% of the time,
but strangely, in the forward direction there's almost no noise at all.
Even approaching a stop with the brakes applied,
there's almost no sound, so within normal riding range
I've reached a state where the sintered pads operate almost silently.
That deafening noise from when the disc pads and rotor were both brand new
seems like a distant memory.
If only the story ended there.
Over this past month, I've ridden twice not just in wet conditions
but in actual rain. The second time was this morning.
And in those situations,
from the moment the pad touches the rotor
all the way until it stops,
there's a continuous ear-splittingSCREECH!!!
It's the same kind of noise as when the pads and rotor were brand new.
The possibility of incomplete bedding is virtually nonexistent.
Just how loud is this? When stopped at a light
in the left lane (or even the passing lane)
next to a car that's already waiting at the red light,
even with windows closed, the people inside
will definitely hear the brake noise—
it's that kind of loud.
Pedestrians on the sidewalk turn around and look.
SRAM does explicitly state that sintered pads
are noisy by nature, but
once bedding is complete, they run almost silent on dry days,
so this "noisiness" might be referring specifically
to wet weather use.
The day after the first loud rainy day,
I rode on dry pavement and it returned to almost silent.
It seems that when water gets trapped between the disc rotor and pad,
it switches into loud mode.
Just wet pavement after rain doesn't trigger loud mode.
I've even confirmed that clearing the water film off the rotor
makes it go silent for a moment.
Depending on the grade, on a clear downhill of about 20-50 meters
where I squeeze the brake lever hard, the SCREECH!!!
at some point just goes...sshhh and disappears.
If the downhill continues, it stays almost silent even in the rain,
but ride 100 meters on flat ground and loud mode returns.
I tried clearing the water film on flat ground at 40 km/h
with strong hard braking (after checking behind),
but that didn't clear the water film. Trying firm modulation
while still maintaining forward momentum showed no sign
of the noise weakening at all—just continuous SCREECH!!!
Since I only use the front disc brake anyway,
I've only been attempting this water film clearing with the front,
but even so, on flat ground (as long as rain keeps falling)
I can't clear the water film and achieve silent mode,
so except for serious downhills,
it seems practically impossible to clear the water film
with both front and rear brakes together.
On my way back there's a section where the road passes under a highway,
and while wet, no rain actually falls there.
I applied hard braking several times in that section,
cleared the water film with a sshhh, going silent,
and the silent mode continued until I rode back out into the rain.
As for the sintered pads after bedding completion,
at the deeper end of brake lever pull,
they do have more stopping power than organic pads—
that's factually true as SRAM states.
But in wet weather, except for very specific downhill sections,
about 99% of riding time is in loud mode,
so unless you're the type who doesn't mind the embarrassment
or doesn't care about disturbing others with loud noise,
using sintered pads is tough.
Besides, organic pads also have better braking in rain than rim brakes,
and organic pads have better
initial bite against the rotor
—that solid grab feeling right when they make contact.
I doubt it's the case, but there's a possibility that bedding isn't actually complete yet
and that once proper bedding is achieved,
loud mode won't trigger even in the rain—
so I'm going to stick with the sintered pads a bit longer.
SRAM says not to use a different type of pad on a rotor bedded to a particular pad,
but next time I might try removing the iron particles from the sintered-bedded rotor
without any special cleaning and switching to organic pads.
SRAM's sintered metal brake pads.
For information on the types of SRAM disc brake pads
（→here）,
and on the break-in of sintered pads
（→here）, please check those out.
Right after the sintered pads finished bedding in,
with the pad lightly rubbing the rotor
and the brake lever slightly pulled,
there was a small フ～ン sound on first contact, but
after using them for a while, the depth at which that sound occurs
shifted slightly deeper.
With a very light touch there's no sound,
and pulling a bit more creates a smallフ～ンat a certain point.
When squeezing the brake lever firmly—
not an emergency stop, mind you,
but normal riding—
even passing through theフ～ンzone, there's no noise.
With the bike stationary, pulling the lever to the depth
where that sound occurs and rotating the front wheel backward
reproduces the sound 100% of the time,
but strangely, in the forward direction there's almost no noise at all.
Even approaching a stop with the brakes applied,
there's almost no sound, so within normal riding range
I've reached a state where the sintered pads operate almost silently.
That deafening noise from when the disc pads and rotor were both brand new
seems like a distant memory.
If only the story ended there.
Over this past month, I've ridden twice not just in wet conditions
but in actual rain. The second time was this morning.
And in those situations,
from the moment the pad touches the rotor
all the way until it stops,
there's a continuous ear-splittingSCREECH!!!
It's the same kind of noise as when the pads and rotor were brand new.
The possibility of incomplete bedding is virtually nonexistent.
Just how loud is this? When stopped at a light
in the left lane (or even the passing lane)
next to a car that's already waiting at the red light,
even with windows closed, the people inside
will definitely hear the brake noise—
it's that kind of loud.
Pedestrians on the sidewalk turn around and look.
SRAM does explicitly state that sintered pads
are noisy by nature, but
once bedding is complete, they run almost silent on dry days,
so this "noisiness" might be referring specifically
to wet weather use.
The day after the first loud rainy day,
I rode on dry pavement and it returned to almost silent.
It seems that when water gets trapped between the disc rotor and pad,
it switches into loud mode.
Just wet pavement after rain doesn't trigger loud mode.
I've even confirmed that clearing the water film off the rotor
makes it go silent for a moment.
Depending on the grade, on a clear downhill of about 20-50 meters
where I squeeze the brake lever hard, the SCREECH!!!
at some point just goes...sshhh and disappears.
If the downhill continues, it stays almost silent even in the rain,
but ride 100 meters on flat ground and loud mode returns.
I tried clearing the water film on flat ground at 40 km/h
with strong hard braking (after checking behind),
but that didn't clear the water film. Trying firm modulation
while still maintaining forward momentum showed no sign
of the noise weakening at all—just continuous SCREECH!!!
Since I only use the front disc brake anyway,
I've only been attempting this water film clearing with the front,
but even so, on flat ground (as long as rain keeps falling)
I can't clear the water film and achieve silent mode,
so except for serious downhills,
it seems practically impossible to clear the water film
with both front and rear brakes together.
On my way back there's a section where the road passes under a highway,
and while wet, no rain actually falls there.
I applied hard braking several times in that section,
cleared the water film with a sshhh, going silent,
and the silent mode continued until I rode back out into the rain.
As for the sintered pads after bedding completion,
at the deeper end of brake lever pull,
they do have more stopping power than organic pads—
that's factually true as SRAM states.
But in wet weather, except for very specific downhill sections,
about 99% of riding time is in loud mode,
so unless you're the type who doesn't mind the embarrassment
or doesn't care about disturbing others with loud noise,
using sintered pads is tough.
Besides, organic pads also have better braking in rain than rim brakes,
and organic pads have better
initial bite against the rotor
—that solid grab feeling right when they make contact.
I doubt it's the case, but there's a possibility that bedding isn't actually complete yet
and that once proper bedding is achieved,
loud mode won't trigger even in the rain—
so I'm going to stick with the sintered pads a bit longer.
SRAM says not to use a different type of pad on a rotor bedded to a particular pad,
but next time I might try removing the iron particles from the sintered-bedded rotor
without any special cleaning and switching to organic pads.