Hi Matt!
Wonderful photo and a fabulous trip -- so glad you were able to go.
About spinning. Yep, that's me, with my hummingbird cadence.
I take this to mean being in as low a gear as possible?
Mmmyeah kinda. Mostly, it means I shift to keep my cadence where it is comfortable for me, which means high and fast with light pressure on the pedals.
In brief, I came to cycling long ago as rehab for knees injured in a car accident. I'm glad I did, 'cos it imprinted on me the need to take care of my knees.
To do so, I found a fast, smooth cadence with little pressure in low gears did the trick. It's been some 37 years since that car accident, but I have ridden this way for so long it has not only become a habit, but my default style. I tend to naturally fall into a cadence of 110-120RPM, and my cruising gear (my Gear 11 on the Rohloff) is only 55 gear-inches, with my other favorite -- Gear 12 -- being 62 gear-iinches. On my other bikes, I tend to most frequently fall between 58-62 gear-inches for nearly all my riding, shifting up or down as necessary to keep to my 110-120RPM cadence. When I drop below that, I shift down. When I feel like I'm spinning-out, I shift up.
With these gears and pedaling cadence, I tend to ride in a "speed window" of 17-21mph/27-34kph and can go pretty much all day at that when riding unladen. When touring with a heavy load on fairly level ground, I cruise along closer to 15.6mph/25kph. When I'm tired or the terrain climbs or wind comes up when unladen, my speed will also drop down to about 15.6mph/25kph, and when it is really steep and I'm winching a full touring load up very steep slopes, I tootle along at about 5mph/8kph, still withh a high cadence. When my cadence drops to about 80RPM or less, I stop and take a break to rest the ol' knees.
Some hills are so steep that with a touring load, it is a series of stops and starts as I slog onward at what seems to me to be a grinding cadence of 60RPM. It doesn't happen often, but it does sometimes, and then I rest often to give my knees a break. If I don't, I really pay for it afterward. They feel all grindy inside, like there's swarf in the lubricant, and that scares me, bringing back unhappy memories of Knee Rehab.
This has all been a factor in choosing my gearing. I much prefer low gears and generally pedal seated rather than standing, but will sometime "honk" up a steep hill by standing. Realistically, I can't pull much beyond am 82 gear-inch high, so why include them? Well, on my derailleur bikes, including a
potential high in the low-90s (large ring, smallest cog) means my middle-range gearing hits the sweet spots even if I don't ever use the high. On the Rohloff, being realistic about what I can pedal at the top end allowed me to go with a 36x17. It tops out at 80 gear-inches, gives me a low of 15in, and put every single gear in-between right smack-dab where it needed to be to match my favorites on my derailleur bikes.
When I went with the 36x17 Rohloff combo, something "clicked' and it became the perfect gearing for me. I do almost all my riding in the top 7 Rohloff gears (my "high range") and then I have 7 Rohloff gears for use in wind and hills when loaded touring. It has been ideal for me, I rarely make the 7-8 shift (which on my hub seems no different than any other shift), and I avoid the slightly greater noise and vibration of the low range in most of my riding -- most of the time, I'm in Gear 11 (55in) or Gear 12 (62in) anyway.
What makes this possible for me (high cadence in low gears; "spinning") is having my feet firmly affixed to the pedals. I'm old-school and have narrow feet that fit poorly in most modern, wider cycling shoes. I've a supply of old Detto Pietro Article 74 cleated cycling shoes and use them with toe clips and straps on my SunTour Superbe Pro pedals -- I have...six? seven? pairs of these pedals, all with sealed roller- and Conrad-style deep-groove bearing combos and they just won't wear out, so I'm sticking with them for now. To change pedals on every bike would be a horrendous expense.
Because my feet are firmly attached to the pedals, I try to pedal in quadrants so my "spin" is smooth. It also allows me to rest my legs while on the bike by switching which quadrant I apply pressure to. It also allows me to pedal nicely through the dead spots, pulling back across the bottom of the stroke (as if scraping mud off my shoe sole), pulling back on the upstroke, kicking forward across the top, as well as pushing down as usual on the forward stroke.
In sharp contrast to my style ("spinning") is "mashing". Mashers typically can pull much higher gears than I possibly could, pedal mostly on the downstroke, and have lower cadences that allow pedaling without the feet needing to be attached to the pedals. Hiking boots would do nicely, and toe clips/straps or SPDs are not necessary. Neither method is "better" than the other; it is a matter of style, of comfort/necessity, and of preference, though spinning might be a bit more efficient at higher speeds. Spinning also allows roadies to keep a reasonably high cadence to get a better "jump" on the rest of the pack when an opening for a bell-lap sprint presents itself. I come from a road-bike background, so that heavily influences my whole approach to riding (and also explains my preference for familiar drop handlebars).
I hope this helps, Matt.
All the best,
Dan.