GTA: Vice City - Bikers spawning on foot in Downtown

All you have to do is edit the pedgrp.dat file which will be located in the data section of your GTA Vice City folder, just keep in mind that the highest amount of ped entries is 16, so choose the 2 peds you want to delete from that area in this case it's called bikarea and the biker peds are called BKA and BKB.