Printing horizontally on its side (more supports) would be ideal for more strength.
See my other Suntour guard if you need a reference.
A fender for my RockShox Lyric RC on my 2021 Trek Slash.
Printed on a rigid TPU (PRILINE TPU - 230c - 80c) Scaled in Cura at 1000%.
Attached with two zip ties. Supports only needed for a clean bridge on the lower mount teeth.
For really hard riding, I've noticed it flexes a bit; it needs added material in areas.
Absolutely fine for lower-grade trail riding; I only found it would flex and hit the tire at times on steep, chattery sections.
For those struggling with print size, use the ones shown in the slicer screenshot I have.
The author marked this model as their own original creation.