Just a short comment on how letting the bike get a little out of shape can affect the ride.
I believe I had let the tires get low on air, from 'tight' to 'pressable' when you squeeze
it by hand.
I also had some rubbing on the front brake; minor, but noticeable when coasting on smooth pavement
as a slight noise.
Finally I hadn't greased the chain in three months.
A little air, adjustment of the front wheel, and some WD-40 on the chain and deraileur, and
behold...the timed portion of my ride went from 18min 32sec. to 16min and 15sec.
That's a pretty amazing improvement in time over just a little tune-up, IMO.
Hope everyone's having a good Holiday. ;-)
-B