Tech tip: "hillbilly" upper links for XRAY X4'24/25

Lately, our team has had good success with mounting the upper link arms, instead of to the standard upper clamp position, to the actual bulkheads - which makes them a lot longer.

Our team (and I can confirm) reports on improved cornering speed and exceptional stability. The reason for this being the "softer" overall geometry which gives LESS initial grip but MORE overall grip, which is particularly useful on higher grip conditions. The best way to describe it is that everything in the roll movement happens a bit slower.

To build this configuration, you can use the standard upper link arm plastics and ball studs, however, you will need to use the longer turnbuckles from the steering assembly (part number 302612). For mounting the upper links to the upper clamp as well topdeck, you need to use 10mm long ball studs (part number 362652).

The next step is how to determine which heights of shimming you need to use on the inside points. 0mm on FF/RR, and 3.0mm on FR/RF equals to 1mm on the inside points with normal upper arms/links. For reference, see this set-up sheet which is attached (for use with standard upper arms) and how it converts to long upper link arms:
FF: 1.0mm
FR: 4.0mm
RF: 3.0mm
RR: 0.0mm

Don't forget that the thickness of the topdeck has an influence as well, so a 1.6mm topdeck will require 0.5mm additional shimming to achieve the correct height. The reference points above were made for when using a 2.0mm topdeck.

Please note that the caster eccentric inserts and screws need to be removed (for clearance) when mounting the longer upper link arms.

Filip Hudy has mentioned this in his tech report from the MIBO International, as he used this configuration on his X4 with great success.

On a side note - please excuse the derogatory term used above. It's been the term used to refer to the above mentioned links by our team. The story goes way back to T2/T3 days when Paul Lemieux was, as always, ahead of his time, in using extra long upper links on his touring car - and thus - the term dates back to that era.