Hi,
It doesn't sound plausible bike handling issues are due to mudguards.
rgds, sreten,
Hahaha! You're right, too!
It turned out to be the bracket that attaches to the through-bolt on the front caliper, which was just fouling on the bottom head bearing cup.
On the way to work this morning I noticed a constant creaking and squeaking, even more persistent than that which comes from my cheapo Shimano shoes. As soon as I realised it increased when I wobbled the handlebars I knew what it was. It just needed a few miles to displace the grease on the bearing cup & cause the squeak.
I thought I'd spaced it out sufficiently with nylon washers but obviously they compress slightly when the nut is done up.
Anyway, it's sorted now; I could have put another washer in there but I elected to bend the bracket with a pair of pliers. Quicker, see!
Bike is great now, once again, and I can hardly tell it has mudguards (which it
won't in the spring!)