Two component polyurethane adhesives contain (a) at least one alkyl-substituted 4,4′-di(aminocyclohexyl)alkane wherein each cyclohexyl group is alkyl-substituted in at least one position ortho to the amino group, (b) at least one 2,4′-di(aminocyclohexyl)alkane or 2,2′-di(aminocyclohexyl)alkane, (c) a mixture of (ii) at least one alkyl-substituted 4,4′-di(aminocyclohexyl)alkane wherein each cyclohexyl group is alkyl-substituted and (ii) at least one 2,4′-di(aminocyclohexyl)alkane and/or 2,2′-di(aminocyclohexyl)alkane, or (d) a mixture of 40 to 99.9% by weight (a), (b) or (c) with 0.1 to 60% by weight of at least one unsubstituted 4,4′-di(aminocyclohexyl)alkane, The adhesives also contain one or more polyols, in which at least 50% of the hydroxyl groups are secondary hydroxyls. These adhesive provide a useful combination of long open time and excellent sag resistance.