Originally Posted by motolab
Aside from the clarification by Rumlover about exposed area (thanks Rumlover!), also note that except for the DJ needle, the chart seems to be arranged with the tips even, which isn't all that useful. It would be better to look at mxrob's chart with the diameters, simply because the measurements are all taken in relationship to distance from the third clip (when adjustable).
As shimming the needle clip preloads the slide spring beyond standard, it results in lowering the slide rather than raising the needle. I would not shim the needle clip unless the goal is actually to lower the slide for a given intersection of throttle angle and rpm. Note that the additional preload from shimming the needle will also make the slide come off the stop at a later point in terms of rpm and throttle position (i.e. more velocity will be required to get it to come up off of the stop).
The only issue I have with mxrob's chart is that it doesn't show the white spacer (or the metal KTM shim) under the clip. That is the stock configuration, and would put the bottoms of the needles (KTM vs DR) at pretty much the same height.
Just the addition of the white spacer alone would put them a lot closer.
Also I believe the general consensus is that the DJ needle in that chart is meant to sit at the bottom of the slide (along side the shelf, not on the shelf). This would also make its installed height a little closer to (DR) OEM then pictured in the chart.
Not sure how the Procycle needle falls in there height wise compared to OEM. A lot of variables to be sure.