It's funny that no matter how much cycling experience we gain, we remain susceptible to those silly mistakes and those "duh!" moments. I am sure I have many, but the most recent one really had me smacking my forehead.
For the past month I had been favouring my vintage Raleigh and not riding the Pashley as much. When I finally did take out the Pashley last week, I noticed that it felt more sluggish than I remembered. I thought this was strange, but chalked it up to my having gotten out of shape and the vintage Raleigh being easier to ride. But the sluggish feeling kept growing worse, and neither of us could figure it out. Until finally, cycling behind me, the Co-Habitant realised what was wrong: My tires were nearly flat! There were no punctures; they were just low on pressure and neither of us had noticed.
I know it's absurd to overlook such an obvious thing as tire pressure; it is the equivalent of wondering why your computer is not working only to realise that it is not plugged into the wall. We do usually top up the air in our tires at reasonable intervals, but my Pashley slipped through the cracks. I wonder whether the cold temperatures played a role in it as well? Now that my tires are re-inflated, the Pashley flies again (really, the difference in speed and handling is amazing). However, I do think that I will replace its native Marathon Plus tires with Delta Cruisers come springtime; the latter just feel livelier and more enjoyable to me. In the meantime: If your bike is feeling slow, do check your tire pressure before looking for more complicated or sinister explanations!