Swarf mudguards need drilling for the brake mount fittings, so the answer is yes. The instructions are to drill a hole using 'a sharp 6mm drill bit' - drilling a pilot hole with a 2mm bit is recommended but not essential. I have pair that I've never used because the guard is too wide to fit between the fork legs under crown and I didn't fancy hacking at them to get them to fit.
Swarf mudguards need drilling for the brake mount fittings, so the answer is yes. The instructions are to drill a hole using 'a sharp 6mm drill bit' - drilling a pilot hole with a 2mm bit is recommended but not essential. I have pair that I've never used because the guard is too wide to fit between the fork legs under crown and I didn't fancy hacking at them to get them to fit.