hello to everyone!
i have the global g-2 and i have bought this sharpener witch have ceramic wheel...it will keep my knife sharp? thanx!!
Globals ship with a convex edge. They make a big deal out of it, but it's more an artifact of the type of sharpening equipment they use, which was more an economic than a performance decision.
The manual and electric pull-through sharpeners Yoshikin sells for Globals (the manual pull-throughs are branded "MinoSharp," the electrics are branded "Global" but are manufactured by the same people who make Chef's Choice), the , sharpen to a 15* flat bevel. Since the factory edge only lasts a few months, and your own sharpening is for the life of the knife, Yoshikin is implicitly endorsing the 15* flat bevel.
As a consequence of the type of alloy used to make the knives, Global knife edges are easily deformed by impact. 15* is not at all conservative. Rather, it's about as acute as you want to take a Global.
Getting back to convex vs flat bevels, there are arguments to be made for each geometry. FWIW, Wusthof claims a big improvement in sharpness since they switched from hand-sharpened convex bevels to laser guided flat bevels.
When everything is said and done, it's a good idea to focus on the best edge you can sharpen as opposed to what comes out of the box. Most people either can't sharpen a convex bevel, or don't want to take the time... so that means a flat bevel. Well, maybe not so much flat, as flatish. Most people have some wobble and other error in their angle-holding, which means that as a practical matter, most knives end up with some degree of convexity.
European manufactures use a wide variety of angles for their knives, depending on all sorts of things which may or may not matter to you. As a sort of rough rule of thumb, I suggest sharpening your Euro knives to a 15* flat bevel. If the edges collapse too easily and need too frequent steeling, try sharpening a 20* micro-bevel over that; in my experience, that works for nearly everything including knives which get used for very heavy-duty tasks.
The micro-beveling advice depends on your skill level as a sharpener. Don't try for fancy-shmancy edges until you can do consistent and effective basic sharpening.