On my Commando/Featherbed frame I get very long life out of my rear chains, the chain I am running now has been on my Norton for 5 years now when the Norton was rebuilt but it had been on the Norton for a few years before the rebuild, since the rebuild it has done 25,000 miles and probly has done 5,000 mile before the rebuild, so 30,000 miles so far, its not a brand name chain, its just a heavy duty chain that I brought from a chain supplier in Brisbane and cost about $40 at the time.
A lot of poeple might disbleive me that I get this sort of milage out of my chains, but I do, I run enough slack in the chain for the up and down movement of the swingarm as well I keep the maintenance up on the chain, I pull the chain off every service and give the chain a good degrease and a good soak over night in oil before putting it back on, I have only adjusted the chain 2x in that 5 years now, look after your chain and it will look after you.
I am just about to replace my chain with one of Andy's chains as I lost a joining link from my chain a few months ago while giving the Norton a good rev out in second gear, it got caught up on my sliding seal in the primary case (the new inner case was short of a shim), I just shake my head when poeple say they only get 2,000/3,000 miles out of their rear chains, in 39 years of owning my Norton I have only replaced the rear chain 5 times, the rear sprocket and front sprocket 2 times and my Norton has well over 140,000 miles on it.
Ashley