What’s the possible diagnosis for the following problem :
I have mech disc brakes and noticed today during a ride that my rear was “randomly” doing squat when trying to brake.
A couple of quick pumps normally cleared the problem, but I’m wondering what the hell is up. Was definitely not one time thing either.
Not a fan of “selective braking”.
LMR29r
roasted, oily or missing/broken pads can cause this.
broken/snapped cable?
Seems fine right now. Though I’m not barreling downhill.
Just happened to notice that I had it pulled all the way in a couple of times - and nothing.
Googling and You Tube searching possible fixes just makes me want to tinker with things that don’t need tinkering.
"Next thing I knew, my bike was in a thousand parts in my basement. "
LMR29r
How tight are your brakes? Cables tend to stretch, and you lose braking power. Could try opening your barrel adjusters.
+1 for @brightwhite. I’d be checking/replacing pads and cleaning rotors if there are no obvious signs of physical damage.
could be pad wear. when the pads wear thin on my hayes mechanicals and i dial them in to compensate (including readjusting the cable), the caliper will stick closed and i lose all stopping power (and my lever will jam all the way to the bar). i think it’s designed to indicate pad replacement.
chek ur cabels
It was just a matter of time 
Sounds like suspect cable routing, perhaps interacting with the suspension action (assuming FS).
Thanks guys - will take a closer look before my next ride. Been a busy week.
LMR29r
Diagnosis - stretched cable as was mentioned. I guess it creeped up on me a bit and just needed some basic tweaking to bring it back where it should be. Put 12 K on it with no issues afterwards.
Thanks for the tips.
LMR29r