Last couple of freewheels and chains have been only lasting about 1500 miles to 1700 miles I am using KMC Z51 chain and Shimano 7 speed 14 34t Megarange freewheels but they don't seem to be lasting as long as they used to. I over lube every 100/120 miles and let in penetrate a while then wipe excess just as always. I used to swap two chains to one freewheel now I have to swap both at once. I always swap out at 1% "stretch" and that is now every six to seven weeks.


Is SHIMANO or KMC quality changed ??? Any ideas ???