I have the nexus premium in a Motobecane track bike from BD.I really love it-but I am kind of forced to ride it because I ride the beach bike trail,and the sand killed my ultegra bike-if I was fastidious about cleaning them,my bikes might last for a while under these tough conditions-but I'm lazy-but a freind who rides half as far on the trail on a mtn bike says he needs a new chain and maybe a sprocket or two every 5,000 miles.When I first built the bike it weighed 24 1/2 lbs judicious theiving of parts from my other bikes brought it down to 24 a cheap N carbon fork,and new stem have it down to just over 23.Its great!- parts came from sheldon brown-including adapter for drop bars.Shimano is coming out with a new version called Alfine-it has a forged casing,needle bearings for reduced friction,and is lighter-I hope to get one and build a LeMond track bike and come out 20lbs or so.the system works well it is handy to change from,say 7th to 3rd while stopped waiting for a light!