Mounting spacer and angle guide for SKS raceblade pro mudguard set

I just bought this removable mudguard set from SKS, and I found it difficult to adjust the placement properly. The first tool (use as a pair) helps by keeping the mudguard in the right position, perfectly aligned with the tire, while you position the strut holder and adjust all the screws accordingly. The second tool materialize the incidence angle to give to the struts.

I suggest using ABS rather than PLA, to avoid damaging the mudguards with a hard material. Print two spacers (0.2mm layer height, no supports required). The spacers do not maintain the mudguard firmly, they rather act as a positioning guide. Use one hand to press it against the wheel while adjusting the mount.

This will only work for the raceblade pro model (not XL) and with 20mm tires (actually, 22). If anyone is interested in other variants and doesn't know about OpenScad, I can help.

Alternative adjustment steps

The difficulty with adjusting everything comes from the many degrees of freedom that the system has. For each strut, the length and the angle w.r.t. the holder are both adjustable. Additionally, for each pair of struts, not only the position along the mudguard is adjustable, but the “incidence” angle w.r.t. the tangential to the outer circle is not fixed either, until you secure it with the provided screw, which will set it approximately at 62°.

So, I used the following procedure to adjust the position of each mudguard element, which has some difference with the one described in the manual:

1. Loosen all screws
2. Immobilize the tire (I simply used a rubber band around the brake handle for that)
3. Position the mudguard with the spacers, which should be spread roughly evenly along the mudguard: far enough for each other, but not too close from the ends. Using the spacers, you just need to adjust the distance to the brakes (1cm)
4. Determine the position of the strut holder that will allow you to position the struts with a 62° incidence angle without exceeding the length adjustment range. Mark this position on the frame on both sides
5. Attach the strut holders to the frame on both sides
6. Adjust the position of the top struts along the mudguard, so that it makes a 62° incidence angle when the strut holder is pressed against the frame. With the angle guide placed as on the picture, its bottom edge should be parallel to the strut.
7. Fasten the top struts' screw
8. Proceed in the same way with the other struts
9. If any of the 62° angle cannot be achieved, or if the strut holder and connectors' position does not appear to be “balanced”, try to raise or lower the strut holder as appropriate, and adjust everything again
10. I marked the position of the strut holders on the frame with white tape once I was sure that the height was OK