1VP34.3/4 Gates 1 groove variable pitch light duty sheave 3.15 (in) outside diameter, 3/4 (in) bore. Use with 3L, 4L, or 5L v-belts. Gates Product Number 7810-1312. Gates variable pitch sheaves are engineered for mechanical drive speed variations that are efficient, easy to install, and easy to adjust for your light-duty applications.