This seems like such a noble goal, I spent the past hour retrieving my carpenter's rule, taking a few pictures, and jotting down measurements.
Description:
The cover is comprised of four pieces of leather
One rectangular piece
Two pennant-shaped pieces: I <
One piece that is pointed at either end (fitting into the two pennants): < >.
The rectangular piece has two identical strap-flaps close to either end. The pennant-shaped pieces each have identical (but slightly different from the rectangle flaps) strap flaps at about the midway point of their lengths. All four of these flaps are on the same edge that we'll call the top. It ends up being the inner circumference of the front face when the cover is on the steering wheel.
Measurements:
The leather is flexible enough, and the construction imprecise enough, that variation of 2-3mm was not uncommon. I tried to take several measurements and list the mean when a part was repeated.
The width throughout is approximately 10.1 cm. Total length of one side (seen in picture) is about 50.5 cm. Stitch holes are exactly 1 cm apart, and 5 mm from the top and bottom edges. Seams were about 2.5mm from the stitching to the cut, and from the stitching to the fold in the leather approximately doubles that, so that most seams bulge about 5mm thick when mild tension was applied.
The
pointed piece < > is 36.7 cm at its longest, and 29 cm at the top and bottom edge. I have no idea why it is pointed at either end, other than a) having four distinctly shaped pieces makes factory assembly much harder to screw up, and b) the angled line on the steering wheel may look sexier.
The
rectangular piece is 36 cm long. Flaps are each attached along a 7 cm portion of the top edge, starting about 8 mm from the seam with the penants. Flaps are 13.8 cm long at their longest using a straightedge. We'll name each half (6.9 cm from midline) of these flaps: Flap A for the part which slightly overhangs the penant and Flap B for the part which is closer to the middle of the rectangular piece, and closer to the other Flap B. The width of each flap is 2.8 cm at the ends, 2.4 cm where it meets the top of the rectangular piece, curving down to 1.7 cm in width at the midpoint (so that width of the leather there is 11.8 cm total, rectangle included). The bottom edge of the Flap A is 6 mm above the top of the pennant, and so the top edge of Flap A is 3.4 cm above the top of the pennant that it overhangs. I measure the Flap A overhang at 22 mm beyond the seam with the pennant, although I just now calculated it at 8 + 35 - 69 = 16 mm. Something ain't right.
Flap B is roughly symmetrical with Flap A, but higher: lower edge is 1.4 cm above the top edge of the rectangle, and top is 4.2 cm above the rectangle. Therefore, the leather for the rectangular piece plus flap must total about 14.3 cm in width before shaping the flap. Similarly, the total length is 36 cm + 4.4 (overhang either side) = 40.4 cm.
Pennants I < are 15.1 cm long at its shortest, and 19.4 cm at the top and bottom edges. We'll look at the pennant piece to the right of the rectangle, the other pennant should be equal and opposite. Flap D/C is along the top edge, sharing a 5.9 cm border with the top of the pennant, a border which begins 7.6 cm from the pointed piece and ends 5.9 cm from the rectangle. Flap C is directly over the "C" shaped indentation in the pennant shape, where it joins with the pointed piece. Flap D is closest to the rectangle, and resembles Flap B. Flap D/C is 3.1 cm wide at both ends, 2.7 cm wide at the midpoint of its attachment to the pennant, and 14 cm long with a straightedge at its longest. Flap C hovers about 4 mm above the top of the pennant for most of its length, while the top of Flap C is 3.5 cm above the top of the pennant for most of its length, widening to a 4 cm shoulder about 2 mm to the left of where Flap C joins the pennant.
Flap D's lower edge is 8 mm above the pennant, and its upper edge is 3.9 cm above the top of the pennant. The overall Flap D/C is assymetrical: Flap D extends 3.7 cm to the left of where it joins the pennant, while Flap C extends 4.4 cm to the right of its meeting point with the pennant.
If you have any questions, post them. I'm planning to install this over the weekend.
