July 2026

Goal for today: true the rear wheel on my commuter after it started rubbing the brake pad on the drive side — about 1.2 mm of lateral hop that had been there for weeks and finally got annoying enough to fix.

Pulled the wheel, mounted it in the truing stand, and went through the process in order:

1. Checked dish first with the dishing tool. Rim was sitting 2 mm toward the non-drive side — not catastrophic, but worth correcting before chasing the hop.
2. Adjusted dish by loosening non-drive spokes a half turn each, then tightening drive-side spokes a matching half turn. Three passes around.
3. Marked the hop with a rubber band on the stay and worked inward from the endpoints — tightening the two spokes nearest the high point by a quarter turn each, loosening the one at the peak.
4. Tension check by feel and by plucking: drive-side spokes should ring higher than non-drive, which they did. No deadeners — good sign.
5. Stress-relieved by pressing down on crossed pairs with both thumbs. Got two small pings. Normal.

The failure was on step 3. I over-corrected on the first pass — tightened too aggressively, about three-quarters of a turn instead of a quarter, and introduced a new 0.8 mm hop 90 degrees away. As it turned out, I'd been counting spokes wrong in low light. Put on the shop lamp after that. The correction took two more passes and added about twenty minutes I hadn't planned for.

What got me unstuck was slowing down and marking each adjusted spoke with a small piece of blue painter's tape so I wasn't guessing which ones I'd touched. Simple fix, obvious in retrospect.

Lateral runout ended at about 0.3 mm, which is fine for a commuter wheel with 28 mm tires. Not show-room, but good enough for daily use and a year of riding before it'll want attention again.

Next time I'd set the shop lamp up before starting, not after the first mistake. Twenty minutes is a cheap lesson but I've paid it twice now.

#workshop #bikemechanic #wheeltruing #diy

Goal was to bleed the rear hydraulic on my neighbor's commuter — a Shimano MT200 lever and caliper gone spongy over eight months of wet commuting, lever pulling almost to the bar on a descent.

Set up on the bench with the wheel out and the caliper level. Shimano SM-MM-1 bleed kit: funnel, syringe, genuine mineral oil. Not improvising the fluid — DOT cross-contamination dissolves the seals. Nitrile gloves; mineral oil stains everything.

1. Pulled the pad, inserted the bleed spacer, confirmed both pistons moved evenly.
2. Threaded the funnel into the lever port (7 mm), filled to the line.
3. Attached the syringe to the caliper nipple, hose submerged in oil — backflow stays fluid, not air.
4. Opened the nipple a quarter turn, pressed the syringe slowly upward. Not a pump; a steady push.
5. Lever feel returned around 20 ml throughput. Closed the nipple, removed the syringe.
6. Worked the lever a dozen times, topped off the funnel, waited two minutes.
7. Capped and torqued the lever port to 0.3 Nm.

The failure came at the caliper nipple. I used an open-end 7 mm wrench for speed, and the aluminum nipple turned a half-rotation past expected resistance before seating — aluminum on aluminum, no thread prep. Spec is 4 Nm; I'd delivered five before the seat feel registered. It seals, no leak, but the threads are soft. I'll replace the nipple before this bike returns.

The bleed itself went cleanly. Lever feel is firm and consistent, no sponginess at the top of the stroke. The whole mistake was on the tightening end.

Next time I'd use a flare-nut wrench on that nipple — grabs two more hex faces, slows things just enough to feel resistance change — and I'd torque to 3 Nm first, check the seat, then go to 4.

#workshop #bikemechanic #brakebleed #hydraulic