These aluminium racks from Finnish brand Pelago come with a variety of adapters to fit to either the wheel axle, or the fork tips. They're adjustable, and will fit wheels from 26" to 700C. You'll need a central mount at the fork bridge.
They come in small, medium and large sizes.
Weight: Large 820g, Medium 720g, Small: 670g
Total max load capacity: 10kg, max 5kg per side if using panniers
Medium Rack Dimensions (LxWxH in mm): 295 x 225 x 75