So I have a B&M cyo dynamo headlight but no fork crown hole to mount it. I was considering drilling a hole in the mudguard close to where it is mounted to the fork and mounting the headlight there.

I was wondering if the mudguard is strong enough to hold the light. It is an SKS commuter mudguard.

Thanks

Daven

Add a hoop strut, right where you want the light, so I supports the light,
rather than the mudguard.. , then attach the strut and the mudguard to each other..

mudguards generally don't do too well when you load it up.
They'll stay in place, but they will swing around.

If you attach the fender onto a metal L-bracket and attach the light to the L-bracket, it should hold up quite well.

Daven: I'd try using a P-clamp or two to mount it to the fork leg up near the crown. Or mount it to the handlebar near the stem.

A properly mounted light can work on a fender, and look rather nice if you do it right. If you follow Fietsbob's suggestions, it should be plenty stiff.

Thanks for the advice - can someone point me to a picture of these "hoop struts" as I'm unfamiliar with them and a casual google doesn't seem to turn up anything immediately obvious. I was considering electrical taping the bracket to the fork just above the crown too - hopefully to give it some extra support.

P-clamps might also work.

Thanks guys

How are your mudguards attached to the fork, is there a threaded hole at the bottom of the steerer tube? What kind of forks?

Something like this. With a little creativity you could rig up a mount; actually it might be worthwhile asking Velo-Orange, they might have some good ideas.

The forks are https://www.on-one.co.uk/i/q/FOOOPOMP...ine-steel-fork and there is a threaded hole at the rear for the mudguards to be mounted to.