It is inevitable that before any event your bike starts to develop ticks and squeaks, the gears suddenly don’t click through properly and the saddle gets uncomfortable.
The reality is you are just getting worried and looking for problems. That inaudible tick becomes a hammer blow, the slight delay is shifting becomes an insufferable gear problem, the saddle is tiny, of course it is uncomfortable, it always is.
That didn’t stop me from panicking over a couple of ticks and frantically switching to my back up bike. This involved swapping over the wheels, having to change over the cassettes becasue they had worn to the chain, changing saddles, swapping over pedals for the recessed spd ones, changing the tyres to make sure I have the best puncture protected ones and moving my saddle bag mount. When I came to run through the gears I found adjustment impossible becasue the chain on the back up bike was worn so I had to fit a new chain.
When I test rode the bike the next day it not only ticked but squeaked as well. It was also sluggish and the set up was all wrong. I swapped everything back.
Now my number one bike seems fine, apart from the minor tick, the slight imperfection in gear shifts and the tiny discomfort of the saddle.