Wemoto stock Tenere parts,�34.50 for a head bearing set.I've always been happy with their quality and service.

http://www.wemoto.com/bikes/Yamaha/X...8-09/#BEARINGS

I thought my head bearings were going but after removing them they looked okay but were lacking in grease.A regrease and refit and they feel fine again.

I did remove them when I first bought the bike and found little grease on them from the factory, slapped loads of waterproof grease in there but after 20000 miles most of it was gone again, those outer seals aren't the best designed.

In praise of the Tenere, I've done 23000 miles, a lot of wet greenlaning and 5 long distance trials and haven't had one bearing or cable fail yet.