carpediemracing 

That's basically true. It's a matter of which system you can or want to fatigue. I'm definitely less aerobic in terms of my relative strength and more muscular, in other words I can't time trial or climb well (maintain a steady output which primarily loads the aerobic system) but I can sprint okay (loads the muscular system and is totally anaerobic, i.e. I could hold my breath while doing that stuff). For me I need to take advantage of the muscular stuff more else I'll go into the red aerobically. This means that instead of spinning like mad on a short steep climb I need to muscle over it. My riding style reflects this - I tend to stand and roll a bigger gear over short hills. I rely on my power to get me through a short climb (meaning 20-30 seconds long, so really short), and I rely on being able to recover over the top by going easier (by drafting others etc).

On the other hand there are riders that are totally opposite. They can time trial or climb all day but can't sprint as well. They need to put the hurt meter more to the aerobic side, loading their strong side. Typically they're better doing longer, steadier efforts, usually spinning and therefore not taxing the muscles anaerobically.

Regardless of what you do at your max it still makes sense to spin when not loading your legs. This keeps the load on your muscles to a minimum, saving them for those anaerobic efforts. You can recover from aerobic load pretty quickly but muscular loads take time. Spinning works your muscles much less than pushing a big gear. In my better races I'll spin at 100-110 rpm for the harder parts of the race, soft pedal at 0-100 rpm (meaning with low pressure, typically when drafting, especially in high-shelter situations). This way I can save my legs for the big efforts with a lot of resistance, like a sprint in a big gear at the finish.

Keep in mind that for a given situation on a climb (i.e you, on a particular climb, at a particular speed) you put down the same power to the pedals. Try this - go to a steep climb that you can do repeats on, maybe in an industrial park or a quiet road. Go up the climb at your "normal" pace. It can be a hard effort, whatever. Note the speed and gear and cadence. Say you climb it at 90 rpm at 8 mph. Now use a really different gear, either much lower or much higher (let's say you use a much lower gear, 2-3 shifts away). Go the same speed, 8 mph. Note the perceived effort (in a lower gear you might pedal at 110 rpm). Now go the other way, use a bigger gear. Go 8 mph. You might pedal at, say, 60 rpm at 8 mph. Note perceived effort.

What's counterintuitive to the rider (but obvious to anyone watching a tracking signal on a GPS map) is that you are doing the same work each time. 8 mph on that hill, in that hour that you rode it (or whatever short time frame), at your weight, it's the same work. The dot on a GPS map is going 8 mph on the hill. Think about how it felt in the regular gear, the low gear, and the high gear. Perceived effort can be deceiving.

Once you get to a certain point (for me it's about 3-4-5 minutes) it doesn't matter what gear I'm in. At that point my heart rate has caught up to my power output and I'm toast no matter what gear I'm in. 20 seconds, I use big gears. 30-60 seconds I have to spin. After that I just pray and hang on for dear life.

On hour+ long climbs I struggle - I find that since I am going the same speed and the same power no matter what gear I'm using I prefer to use a slightly larger gear. Mentally I have a hard time spinning high effort for 60 minutes but I can push a gear for 60 minutes. I tried using all sorts of gears on the one really long climb I do (Palomar Mountain - it takes me almost 2 hours to get from bottom to top). I found that a 39x23 worked better than a 39x25, simply because I could turn the 23 over at the same speed I could spin the 25 (but I found spinning the 25 mentally taxing - I'd naturally slow down to the "pushing the 23" cadence). I can't turn a 21 over too well so I'd use it only when it flattened out a bit (and higher gears as well). When people talk about "needing" a particular gear for a climb it only reflects an intersection of power output, grade, and pedaling style. Many people can use higher gears than they think, they just haven't tried it.

A story on how I learned that lesson:
http://sprinterdellacasa.blogspot.co...ic-and-me.html

And thanks for the kind words. If I can help someone then it's all worth it.