• City:

    Okay, that rules out the steering bearings then.

    Check the bolts which fix the disc rotor to the wheel. If those are not equally tightened then it could make the bike do all sorts of funny things.

    Axle is unlikely. This is a very basic thing. But hope the front wheel is fixed properly. Highly unlikely, but still good to check once. If the wheel is not fixed properly it will wobble a bit. And shake a lot on braking.