On my shimano 2300 8 speed gear set I replaced the chain after it started slipping. Thing is the new one has failed twice (bent links, failed pins). Repaired the bad links with some 9 speed links left over from my mtb chain. They fit in fine and work great. They look almost the same size as well.
Thus... would my drive train care if I dumped this weak chain and just put in a quality 9 speed chain? Its getting harder to get quality 8 speed chains these days.