I was very interested in the 525 chain option that Kemizz is using.
I seem to get 4000miles out of a chain then it suddenly wears/stretches.
I oil weekly and clean the outside surfaces with paraffin occasionally. (maybe not oiled regularly enough?)

Anyway, I like the sound of these.

http://www.off-the-road.de/XT-660-Z-...660-HEAVY.html

Thanks Kemizz for the link. ;)
(for some reason I lost OTR, lol couldn't find by typing in 'OTR' or 'off the road' was getting fraustrated.... missed out the hyphens ... Doh...)