Bit of backstory: Just over a week ago I got my C-bag's strap caught between the front wheel and fender, which then folded the fender in half as it went behind the wheel. The steel stay also got bent out of shape.

The shop convinced to buy a new fender set at a discount, which I did, and they installed it.

However, now I'm finding a steady creaking sound when I go faster than a snail's pace, especially when I lean on the handlebars. This has never happened before the incident.

While I'm planning to bring the bike down on Wednesday to have it checked out (they aren't opened tomorrow), I'm wondering if anyone can suggest what might be the problem. Thanks.

Can you check any part of the fender or mud flap touching your wheel while it turns? Bare hand can be quite useful tool when adjusting this kind of error.

Check the wheel... loose spoke, misaligned rim?

Often the creaking is elsewhere , 1 source the rubber suspension block

a dab of grease on the bolt thru it helps.

My folder creaked when the fold mechanism wasn't done up tightly enough (in the unfold position, of course). I tightened the stem, and the creaking stopped.

It's a Bike Friday, so the fold is different, but it may be worth checking all the nuts and bolts you do up as you go from fold to ride to be sure they are done up tightly.

hmm. sounds like you need a new front wheel.

perhaps the bike shop can sell you one at a discount. come to think of it, this might be a good opportunity to upgrade to a phil wood front hub with titanium axle.

Or start a Dynohub-Light setup with this New Wheel SON XS

a radial spoked small hub dynamo in anodized finish and colors ..

their Polished, flanged Brompton hub gets a cross pattern..

Climb out of a money pit, and fall into another one ...

I simply asked about a weird creaking sound, and some people suggest several-hundred-dollar solutions.

Oh you guys

Thanks for all the suggestions guys, I'll get home and try them out.