The grooves cannot have any aerodynamic purpose as they are covered by the sticker.
What no visible groves in your Quark? I checked the picture again that I posted earlier. Since I just borrowed it from another
post of yours in another thread I figured this is what you have. And indeed there is no visible groove.
My theorie on all this mess now goes as follows:
- ta0 you have the tungsten quark. That has a smaller diameter I read. I have the brass Quark that is somewhat larger.
- the Quark top was produced with different bodies, depending on the flywheel in use. The picture in my post earlier probably shows bodies for the brass Quark
- only one sticker was designed for the Quark. It fits the tungsten top perfectly, but in my brass top it leaves the outer grove partially uncovered.
-
So, no physical finesse here it seems. Just some laziness in designing a second sticker. Like my laziness in taking a photo of my own Quark right at the start.