Chain Drive

Steel gear teeth caught the morning sun. A mountain bike leaned against the garage wall. I rolled straight up to the drivetrain. Massive knobby rubber tire towered high above my roof. Heavy-duty engineering. I lined up square and pressed my front bumper into the lowest cog of the chainring. Slow, deliberate shove. Metal clicked. The greasy chain tightened, steel links shifting with a sharp mechanical snap. The pedal arm rotated an inch, then locked rigid against gear tension. Solid ratio. I backed off two inches and let the suspension settle. Cold iron holding under load. Real machinery.