Yep, I'm discovering the advantages to a lower cadence than I'm accustomed to, especially for climbing. I just posted something about this to another thread but I'll try to summarize it here.
I naturally seem to prefer spinning right at 90 rpm, like clockwork. But by last year I'd hit a wall in performance. I could sit and spin alongside stronger cyclists mashing up hills, and sometimes pass them, but my heart rate would peg and I'd be gasping for breath. Nothing I did helped in training. And I consulted every credible theory and training technique.
But at my age and physical condition I'd hit an insurmountable wall. That's partly due to lifelong respiratory problems and probable lung damage (exposure to TB as an infant, many bouts of pneumonia, bronchitis, etc.).
Then there's allergies and asthma problems. Besides that, I also have a deviated septum from amateur boxing. I'm not sure how much it hinders my breathing but it must have some effect. And my nostrils and sinuses always feel congested no matter how much decongestant, Flonase, saline wash, etc., I use. I can rarely smell anything milder than a garbage dump or animal carcass along the road. Maybe once a month my head clears up enough to smell ordinary stuff, which reminds me how much I'm missing. And I can actually breathe on those rare occasions.
That's one reason why I'm switching from high spin to low cadence pedaling. I've read all the theories and lab tests applied to pros. I've tried both methods myself. There are advantages to high cadence but only for folks with really good cardio and respiratory systems. When I try seated spinning on some climbs my heart rate is pegged and I'm gasping for air.
But when I practice high gear, low cadence, seated and standing, on my own, my heart rate stays much lower and I'm not strangling from lack of oxygen. I just needed time to work on adapting to a new technique, including more leg strengthening with squats, lunges, moderate weights, etc. My body resisted the change for awhile and my legs would cramp and burn out quickly. But now I can stand to pedal for up to a half-mile at a time if I'm careful to monitor my effort.
Since the spring I'm mostly riding a '93 Trek 5900, one of their early monocoque carbon fiber frames. Nice bike for what I paid, much lighter than my steel bike. It came with non-original components and a Biopace chainring setup, which I'd been wanting to try. Like some other folks who've ridden Biopace I found it felt more natural at a lower cadence, around 80 most of the time and 60-70 on climbs, even lower when standing to stomp up climbs, around 40-50 rpm. So over the year I've consciously modified my cadence and leg strengthening. Just the past month on good days it seems to finally be coming together.
But I'll need a cadence meter on the Trek to be sure. I have sensors on my steel bike, which mostly sits on the trainer. I ordered one this weekend, should be here in a day or so. It'll put some numbers to my impressions about whether a slower cadence and harder gears is working for me. I do know my average climbing speed is the same but my heart rate is lower and I'm not out of breath. So while I was comfortable with spinning at moderate effort, it wasn't working for me when I had to crank up the effort. And I'm comfortable using both techniques as appropriate.