my car is chain drive , and have chained since 1966 , so if we ''shorten'' the chain by one roller ,basic you cant - so you have to remove 4 rollers (2 links) and inset a link and a half (3 rollers . this ''half'' link is available from good motor bike shops , hope that explains links .Because I didn’t know what bit counted as a ‘link’, I thought the two piece counted as a link.