I Took my sv1000 shock linkage apart yesterday to clean and grease the bearings up, only to find (a mess) the bearings where red rusty and basicaly totaly nackered. the mileage on my bike? 15,000mls. the parts from suzuki to put this right are around £70. This is probably due to suzuki not putting alot of grease in from the factory but id say if you want to keep your rear suspension working nice and dont want to be paying £70 out for parts get those bearings greased every 10,000mls at least, they have a hard time down there with the heat from the exhaust and all the crap off the roads.
