Sealed versus unsealed

A sealed bearing keeps its lubricant in and contaminants out. In a studio environment full of skin cells, dust and cleaning residue, that seal is doing most of the work of keeping a carriage quiet after year one.

Unsealed bushings and open wheels are cheaper and perform acceptably when new. They degrade in months rather than years, and no maintenance reverses it.

Wheel count and placement

Most carriages run on four to eight wheels. More wheels spread load and reduce individual wear, but placement matters more than count — wheels positioned well outboard resist the lateral rocking that makes a carriage feel loose.

Test for this by rocking the carriage side to side at the far end of its travel, where the support is least. Near-zero movement is what you want.

  • Sealed bearings — the key durability marker
  • Wheels positioned outboard resist lateral rock
  • Machined rails, not folded or stamped sections
  • Wheel material: polyurethane runs quieter than nylon

The rail is half the system

A good bearing on a rough rail is still a rough ride. Rails should be machined and smooth to the touch along their whole length, with no seams, welds or fixings in the running surface.

Rails are also the component most easily damaged. Grit trapped under a wheel scores the surface permanently, which is why rail cleaning is the highest-value maintenance task on the machine.