KiwiDallas

“There are three kinds of men.

"The ones that learn by readin’.

"The few who learn by observation.

"The rest of them have to pee on the electric fence for themselves.”
― Will Rogers

I thought of this recently. I'm new to road bikes with disk brakes; spent a lifetime on rim brakes.

I thought, "I wonder how hot these here disk brakes get?" So I rode down a very short hill, stopped hard with the front brakes, and touched the disc rotor with my bare fingers.

As my boss once said, "I don't learn real fast - but I learn real good."

=K

MoAlpha

Ha! So now you know skin oil on the rotors will make those brakes squeal like stuck pigs!

Koyote

Yep, don't touch the rotors! But since you have, I think you can clean them with something....Someone else can confirm, but you might need to wipe 'em down with brake cleaner, or maybe isopropyl alcohol will work.

tempocyclist

Sometimes, you just gotta learn the hard way! 😂

cxwrench

IF you touched the braking surface and IF the rotor actually got contaminated w/ skin oil...AND you used the brake again at all it's too late to clean. I doubt they got contaminated badly enough to need cleaning.

Kedosto

As lesson learned the hard way is not soon forgotten.

dabac

Reminds me of ol' Grandma.
They ran a dairy farm, and were the first in the family to have a (industrial) high pressure washer.
I was maybe seven and approached the contraption with awe and curiosity. Was even allowed to run it a little under grandmas supervision. I carefully dabbed my finger at the jet, like you do to check if a surface is hot. Further out first, then closer and closer to the nozzle. Got to a point where the sensation intensified, pulled back and squealed "it burns!"
Grandma said: "don't be stupid, it's hooked up to the cold water faucet".
And to prove me wrong, she put her whole palm straight into the jet, maybe a foot from the nozzle.
She pulled it out fast enough, but not before it had given her a blister that occupied most of her palm.
Grandma went pale, wrapped her hand in her apron and walked off, not to be seen again until dinner time. Even then she kept unusually quiet, and with her hand in her lap.

Now, strictly speaking, it probably wasn't a burn blister. The injury mechanics were most likely something else. But my little dabbling certainly FELT hot. And grandmas blister, when she forgot to hide it, certainly looked just like a whopper of a burn blister.

Still to this day I wonder what made her so eager to disprove a 7-year old who's basically saying "this hurts".
I suppose I should be grateful I hadn't been tapping at my head with a claw hammer....

PeteHski

Clue's in the name, lol

MoAlpha

Any organic solvent works fine, but I was joking.

Koyote

Oh, really? I thought I’d read that you are not supposed to touch the rotors.

MoAlpha

Oh, definitely not, but the guy burned his finger!

Koyote

I think we’re both right. He needs isopropyl alcohol, but it should be applied to his finger. 😀

Trsnrtr

There is a difference between believing and knowing.

eduskator

the Hot way, you mean!