I have put about 9,000 miles on my Mavic Ksyrium ES wheels in just over 2 years. While the rear wheel rotates very smoothly, I am hearing some bearing noise. I don't have any looseness or tightness in the hub but there is some very slight ball movement noise in the bearings as the wheel rotates freely without the chain on.
What type of life should I expect on these bearings?
Who supplies replacement bearings for Mavic Ksyrium ES wheels?
The bearings are all standard sizes that can be obtained from a large number of sources. The front requires two 6901 bearings and the rear requires one 6903 and one 608. The right end of the cassette body also has one number 608 bearing in it.
If you have never relubed the freewheel mechanism, I'm amazed it has never squealed while coasting. Check the pawls and the cassette body for wear. The plastic bushing at the left end of the cassette body can wear excessively and the only solution is a new cassette body for about $50. If you buy that, I'd get new pawls and springs (about $15). Then you don't need the second 608 bearing.