Setting pad alignment and cable tension
Okay. We cleaned everything, we sorted out why one side was grabbing with the barrel adjuster. Now we're doing the real fix, which is getting the pads actually lined up and the cable pulling the right amount. This is the lesson where your brakes go from "usable" to "actually good," so stick with me.
Pad alignment first
Whether you've got rim brakes or mechanical disc, the idea's the same. The pad needs to hit flat and even, not at an angle, not just skimming the top or bottom edge.
Rim brakes. Squeeze the brake lever slowly and watch where the pad lands. You want the whole pad face contacting the rim at the same time, sitting maybe a millimeter or two below the top of the rim, nowhere near the tire. If it's hitting the tire, you're going to chew through a sidewall eventually, and that's a bad way to find out.
Most calipers have a bolt holding the pad on. Loosen it just enough that the pad can pivot, angle it so the whole surface touches the rim evenly, then snug it back down. Some people do the "toe in" thing, angling the front of the pad in slightly so it hits first and quiets down the squeal. Honestly, for a commuter bike or a kid's bike, I don't sweat toe-in much. Get it flat and even, that'll get you most of the way there.
Mechanical disc. Same concept, different geometry. Loosen the two bolts holding the caliper to the frame, squeeze the lever and hold it, then tighten the bolts while the caliper is centered around the rotor. The lever does the centering for you. Let go, spin the wheel, and check the rotor isn't rubbing on either side. If it is, nudge the caliper a hair and try again.
Now the cable tension
This is where a lot of people either give up too early or crank it too tight and wonder why the brake won't release.
Pull the brake lever. You want it to grab with authority somewhere in the first half of its travel, not down near the handlebar, and not so stiff you can barely squeeze it. If it's loose and mushy, you need more tension. If it barely moves before it's locked up, you've got too much.
There's a pinch bolt where the cable clamps into the caliper or brake arm. Loosen that, pull the slack out of the cable by hand, and retighten while holding the tension. Small adjustments here. You're not muscling this bolt, you're finessing it.
And here's the thing, this is low key the part people mess up, because that bolt is small and it's tempting to just crank it down hard to make sure it holds. Don't do that.
I rounded off a bolt once doing exactly that. Wasn't even this bolt, it was a different job entirely, but same mistake. I had the wrong size Allen key, it was close enough that it seemed to fit, and instead of stopping to go find the right one I just leaned into it. Rounded the head clean off. Had to drill the thing out afterward, which is not a fun way to spend a Saturday afternoon and is definitely not a three-dollar fix anymore.
So: right tool, gentle first. If a bolt is fighting you, stop. Check the size. Most of these pinch bolts just need snug, not crushing. You're clamping a cable, not building a house.
Fine-tuning after the pinch bolt
Once the cable's clamped, use the barrel adjuster we talked about last time to dial in the last bit of tension without loosening the pinch bolt again. Turn it out a little if the lever feels loose, in a little if it's dragging. That adjuster exists specifically so you don't have to keep messing with the pinch bolt for small changes. Use it.
Spin the wheel. Pads should be off the rim or rotor completely when you're not braking, no drag, no ticking sound. Squeeze the lever. Should grab solid, evenly, no more grabbing on one side than the other.
The opinion part
I'll say it again because it's true here more than almost anywhere else in this class: your brakes are probably fine. You don't need new pads, you don't need a new caliper, you need this ten minutes of alignment and tension work. I see people ready to buy parts when the actual problem is a pad sitting crooked or a cable with too much slack. Do this first. Spend money later if you still need to.
Before next time
Do this on both brakes if you haven't already, front and back, and actually test them in the driveway before you call it done. Squeeze hard once at low speed and make sure nothing feels off before you trust it on the trail.