Twin-608 V-Groove Gate Track Roller
A 64 mm OD, 30 mm wide rolling-gate wheel with a 90° V-groove (12 mm deep) that rides an inverted angle-iron track. It has a root relief slot so the rounded heel of the angle never bottoms out, and two press-fit 608 bearing pockets (22.05 mm) that take an 8 mm / 5/16 in axle bolt. It replaces the grooved wheel on a sagging sliding chain-link or wood gate, which stores usually only sell as a full roller assembly.
mechanism gate 608 roller