I'd check tyre pressures first then steering head bearings - whilst they may feel ok (sometimes it's difficult to really tell if the cables and wiring are acting as a 'damper' when swinging the bars from lock to lock); it may not have noticeable play but they may be very dry and probably haven't been not greased since leaving the factory.

I was amazed at how dry the head bearings on my three year old bike were when I did them recently.

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Simon

Brighton, UK