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How can I try to tighten a little the bearing ? (not too much though, I know!)


Your best course is to replace the stock, existing bearings with the tapered roller bearings that are available, unless you are experienced with bearing set up, and have the appropriate puller set and press to install, I would find a capable mechanic to do it for you. The manual calls for a neutral preload setting, but I have found that to be slightly tight, with a dial indicator mounted static on the frame spine and the probe 90 degrees to the tree shaft, slightly less than half a thousandth of an inch shaft wobble to be the best all around. I also use waterproof boat trailer axle grease for exposure to the rain in the long term. Go with the new style bearings and a proper set up and you will never have to mess with that aspect of your bike again. Just so I am not ignoring your initial question, remove your speedo bracket and speedo as one, via the two 6 mm bolts where they attach under the front of top tree plate and let the unit hang over headlight, remove your risers/handlebars as one, by the two bolts that are under the tree top plate and secure the bars, wires and assorted cables on a blanket atop your tank, I have found securing them with a rope hanging down from above to work well if you can manage it somehow. Remove the chrome nut and washer (the large one in the middle on top of the plate), loosen the fork tube cap bolts that secure the top plate and tubes, slightly spread the slits with a appropriate wedge, both sides (a few drops of light machine oil, applied to the tubes/tree plate will help things slide). Work slow and evenly drive the top plate up and off the tubes and middle nut you removed. A small plastic dead blow hammer works the best or a piece of wood and a regular hammer will work too. Drive the plate off side to side and tap the middle underneath but go lightly and be patient, did I mention your progress must be kept as evenly as possible. Once the the plate is off you will see two nuts, the top one is the jam nut to hold the bearings preload set of the one underneath it, the thickness of the nuts are 7-8 mm thick so having the thin factory wrenches, come into their own at this stage. Loosen the jam nut, set your preload via the one that is under it, than without losing (allowing the bottom nut to move) your desired set, retighten the jam nut, reassemble everything in reverse order and go ride. If I have forgotten a step, I'm sure somebody on here will edit my, IIRC sequences. Always remember, bearings that are set up too tight, tend to fail prematurely, one reason is the lubricant/grease is displaced from the mating surfaces by the lack of internal clearances. However you decide to proceed, best of luck to you in all endeavors.