Hydrogen bridges of the type X-H...A...H-X, as have been observed in amide-templated rotaxanes, are investigated. The acceptors A are systematically varied by electron withdrawing and electron donating substitutions. A fairly linear relationship between the charge on A or its Is energies with the bonding strength of the hydrogen bridges is found as long as the X-H moieties retained their character and are placed in a sterically favorable position. The strength of the twofold bridges is about 1.5 times that of a corresponding single hydrogen bond. Changes in the relative position of the two X-H moieties relative to the acceptor A show that steric requirements can dominate charge-transfer properties in hydrogen bonding and point out the importance of proper steric concordance in twofold hydrogen bridges. A search for twofold bridges in biological systems is suggested.