Originally Posted by Sidecar Jockey
Like has been previously said, there is no differential, so the sidecar wheel MUST slip when 2wd is engaged. The drive ratio of the sidecar wheel is LOWER than that of the rear wheel of the bike, so if the sidecar wheel can't slip you will either drive in a circle or blow out your tranny. I know Ural owners that had the latter happen...
Really? I'd be interested to see their Urals. Every one I've ever seen (including my own) has a driveshaft straight off the rear end to the axle stub on the sidecar. I'd like to know where their gear reduction is hidden.