If using a derailleur chain, rather than straight chain, it is unclear why rohloff is concerned with disturbing the chain line by >1 mm. Nevertheless, I could probably find a combination of BB and spacers to maintain the chainline. I understand the reason for the chainglider and thus my interest. However, with surly SS chainrings and relatively new chains having factory wax, or after I clean the chains, the look of all that shiny metal on our tandem is pleasing. To cover with a black glider detracts from that a bit, but of course 'tis aesthetics.