Recently, a Nivex touring derailleur sold on ebay.
The derailleur has a lower "jockey wheel" that looks similar to a cyclo (in side view) in that there are large disks on the side, presumably to retain the chain. The Nivex jockey wheel side disks appear to be fixed. A normal sized jockey wheel appears to rotate between the plates. On a cyclo derailleur the disks are part of the jockey wheel and the whole assembly rotates as the chain moves through the derailleur.
The disks on the Nivex seem to be separate from the jockey wheel.
Can anyone on the list confirm if the Nivex lower disks, rotate? Thanks.