I must admit I'd given up on getting the CG to work, but I will have another look at it tomorrow.
It seems to me in the light of my experience of several years now that if a Chainglider doesn't work on a Rohloff-equipped bike, the owner has fitted the wrong model of front end (there's a long and a short version to suit various chainstay lengths, and several versions in each length to fit very specific chainring tooth counts) or rear end (there's a specific Rohloff back end it isn't optional, it is essential). It is also important not to try to stuff too wide a chain or chainring into it. You're supposed to cut (especially the long version of) the Chainglider front end to length; that cannot be a criticism; it's a design feature to make it fit many bikes.
Beyond that you can go wrong by fitting it too tight, so the chain drags or (theoretically at least) too loose but this last problem is one of patience: you have to move the notches that lock the thing together in or out one notch at a time until the Chainglider operates silently, litterally by gliding across either the lube or the air inside -- its like magic once you have the thing fitted right..
As much as I like the idea of a clean chain-side, I'm not sure I will tolerate ANY noise, but I really should give it a proper trial
A properly fitted Chainglider makes no noise you will hear over general road noise. You know that sighing noise a Rohloff makes in gears 5-6-7 when it is new, that becomes less obtrusive as it runs in? That's ten times as loud on a run-in Rohloff box as a well-fitted Chainglider. If your Chainglider is audible over the sound of your tyres, you didn't fit it right. Man, I'm maniacal about noise, and I'm happy to stamp the Chainglider "Approved as silent". On the solid white stripe on a smooth road, useful to kill the relative "roar" of the Big Apples (in truth not very loud tyres), my bike, complete with Chainglider, glides like a phantom, zero noise. The four top parameters that persuaded me to spend BMW money on my current everyday bike were low stepover without sacrificing stiffness, steel, lugs (no welding!), utter silence.
(as long as there's no damage to my hub).
This is ancient, ancient street corner gossip being thrown up again and again and again by people who don't pay attention the first ten times they are told. It's been years since Hebie launched the Rohloff-specific rear end for the Chainglider (and equivalents dedicated to several other popular hub gearboxes as well). If a Rohloff pilote damages his hub by fitting the wrong rear end for his Chainglider, he has no one to blame but himself. But the Chainglider damaging a Rohloff hub isn't even a remote possibility, and hasn't been for several year, for cyclists with their brains in gear.
Check your Chainglider rear end against the photos on the Hebie netsite to ensure you have a Rohloff rear end.
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If you don't want the Chainglider because chain-cleaning is your thinking time, or you think only sissies have chain cases, or you don't like the charcoal grey it comes in, or any other aesthetic reason, or plain prejudice, fine. That's a matter of taste. But I sigh when hear technical objections to the Chainglider like noise or damage to particular hubs. The thing, given only that you bought the correct subcomponent specifications for your bike and fitted it right, just plain works, fit and forget.
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All that said, a consideration when fitting a Chainglider to a few particular Thorn models (type and size to be determined in each case -- it may be that all the guys who reported this here have the same size rear triangle) is the possibility that the Chainglider may intersect slightly with the particular geometry of that Thorn frame, and rub paint off the seat stay. But that has been solved by several forum members shaving the Chainglider in the right place with their pocket knives...
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All in all, I think a properly fitted Chainglider is one of those landmark components that everyone should experience at least once in a lifetime.
