In Detail: Sauber C31 Rear Suspension mounting clevis


Sometimes the level of engineering in F1 is best described by the smaller simpler parts, an example of this is the humble suspension mounting.  This part being the point where the wishbone meets the gearbox to allow the suspension arm to pivot around it spherical bearing.  This example is a 2012 Sauber C31 rear wishbone mounting clevis, but is typical of several similar clevises in my collection of F1 parts, albeit they appear to get a little more sophisticated in shape each year.


This part (C3131 1051R#12*D) is described by Sauber as ‘Lagerbock PKT F Design POS’ and is recorded as having recorded a mileage of 1437km.  Dense and highly polished the part appears to be made in titanium and fitted inboard to the right rear of the car, although it’s not obvious which exact location is it (upper-lower wishbone, forward-rearward leg).  From its shaping, my assumption is it’s a top wishbone forward leg mount, therefore mounted towards the top-front of the gear casing.


In overall size it is some 100mm long, 50mm wide and 50mm deep.  Mounting to the gearbox with three M7 bolts, the part appears to be substantial, but it’s been heavily machined to reduce weight, so the part weights just 160g.  This weight saving being largely being the thin wall sections and a deeply pocketed rear face.  The flanges forming the mounting points are just 5mm thick and the thicknesses forming the clevis mounting itself being just 7mm thick.  Behind the mounting flange the pocket is some 30cc in volume, by my calculations using the SG of Ti this saves 135g!


The clevis itself is formed around a dia 38mm opening across a 20mm gap, the pivot formed around another M7 fastener. The inner faces being slightly proud to allows the spherical bearing and top hats to slip in between.  Then the M7 fastener screws into a thread formed into the lower clevis flange, rather with a seperate nut.


A small zip tie fitting is bonded to the lower surface, presumably for cabling to emerge from the wishbone itself to join the rear electrical loom.