The present invention concerns processes for reducing water in never-dried fiber comprising copolymer derived from the copolymerization of para-phenylenediamine, 5(6)-amino-2-(p-aminophenyl)benzimidazole; and terephthaloyl dichloride, the process having the following steps in a continuous process, (a) a step of drying a never-dried fiber having at least 0.1% sulfur at less than 150° C. until the moisture content of the fiber is less than 60 weight percent; and (b) a step of further drying the fiber above 150° C. while the moisture content of the fiber is no more than 60 weight percent; and the fiber being further heated to at least 350° C. in either an additional continuous or separate step.