Is there any way...
Hi Dave; I'm delighted you've joined the discussion! Always good to have you on-board.
I think what you've outlined is the way forward, and my mind has been working along similar lines at this end. I was out in the shop last night, using my miniature bending brake to put some nice, tight corners on some sheet stainless I cut to fit with the electric bandsaw and die-grinder. It looks promising.
What I was thinking was something that would resemble (with regard to position, of course) the Rohloff chain guide (Vik Banerjee, late of this Forum, has a nice photo of one here: http://www.flickr.com/photos/9932605@N08/2472121373
) and attach it to the right dropout. Folded out of sheet stainless, it wouldn't be very thick.
The right dropout on the Nomad has two threaded bosses, and Thorn have a stainless adapter that bolts to them to provide a single 6mm boss for mounting the rear rack. It might be possible to use longer adapter bolts to capture the chain guide on the inside using a couple nylock nuts.
I like your approach as well, and perhaps something in the middle will do the trick. You've got me thinking a small block of polycarbonate could be milled to do the job in that same location. If I did this, I'd take care to chamfer the entry and exit to avoid snagging the chain if it came off, something like this: ) (
I'm really a "bug" for keeping my derailleur drivetrains clean and well-adjusted, so it is unlikely I will ever let the Rohloff chain stretch enough to come off. On the other hand, a person can't always foresee all problems midway on a long tour, and it would only take once. I'd really hate to have the chain tear up the beautiful black-anodized finish, so a little "chain watcher" would surely do the trick.'
Thanks, Dave; brilliant idea as usual!
All the best,