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[paulhaines]

If any of you have a Mavic wheelset (XC range of Crossmax, Crosstrail, Ride etc) and also some of the road wheels and experience a very loud howl/scream when freewheeling here is the cause and fixes.   The symptoms are: * when freewheeling, usually fast (30Km/h plus) * loud howl/screaming from the rear hub, bike vibrates and there is resistance to the wheel rotation, cassette might rotate and slacken the chain * when you pedal it stops   The cause: The freehub body has a nylon ring bushing which rotates against the inner hub body. That bushing can wear, particularly if exposed to regular dirty ride conditions.  If you grab the cassette and try to rock it side to side, and see that the whole cassette has some play, it means the bushing is worn. I assume when freewheeling at speed, this play will cause the freehub to vibrate/resonate and cause the howling noise.   Prevention & cure: Firstly, regular servicing of the freehub is strongly advised.  Clean out the freehub body and bushing surface, and lube with MINERAL oil only.   It must be mineral oil for its low viscosity. Grease will trap dirt and has too high a viscosity. If the bushing is just dirty but not too worn, a service & lube can cure it. If the bushing is truly worn, it can be replaced either as a unit on its own (independent parts makers have too) or a whole freehub body. There is one permanent solution - replace the bushing with a ceramic bearing unit - and one parts maker called HubDoctor offers just this.  HubDoctor also makes bushings they claim are longer lasting as are harder and lower friction   Links: How to service: http://roguemechanic...mechanic-m.html http://www.5min.com/...ic-Hub-66770570 Hubdoctor parts: http://cgi.ebay.com/...5#ht_1217wt_907   Hope this helps you all out there!    

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[The Wrench]

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This is still relevant information even though MAVIC has moved most of their high-end MTB wheels from a 2-pawl system to a 4-pawl. Always remember to avoid rebuilding high-end wheels with grease (even lightweight grease is too gooey=high viscosity). Hub oil, from the manufacturer, is still the answer. And, keep an eye on nylon (plastic) bushing wear.