Ah of course, cost - I didn't think of that one! Everything's always about money!! In regard to noise, I'm sure if they're worn they may rattle about a bit, but then you know it's time to change them! As soon as my bike used to rattle, I'd either adjust the tensioner or put a new chain on there - nice and simple. And when running properly it didn't make a racket or anything like that. As for my brother's engine, which has some 'Duplex' chain with fancy nylon bits all over it - that's as quiet as any other engine I've heard. I just think it's a pain thats all! I suppose there's no way of getting a chain replacement...?
