So much of it is a mind game. which is why you shouldn't get too caught up in the mapmyride/GPS info. Don't get me wrong it's useful but it can be counterproductive to obsess on it.

I have a really good friend who we have now dubbed "Old Fearing Hills" after a road we saw on a ride once called, "Old Fearing Hill Road" this guy is actually a really good rider but he gets totally psyched out by hills. If he knows there's going to be a long climb on a road ride or tour he starts talking about it the night before. He'll know from his Garmin exactly when we're approaching it, when he sees it he'll start to slow down, say stuff like, "Go on ahead. I'll see you at the top." A little part of him gives up, and off the rest of us will go. Once we're out of sight he climbs really well and when he gets to the top he's in great shape but he'll repeat this routine with every hill.

Over time you'll learn how to "attack" these hills. Maybe some of them will need an immediate shift down into a considerably lower gear, others may need a more gradual change of gears. Occasionally you may want to stand, though I recommend getting used to doing them seated, especially for a commute- its not a race (unless you want it to be).

The main thing is to keep your knees from suffering. Know the difference between "good" pain and "bad" pain. If you're suffering with muscle fatigue that may not be so bad and may be a necessary part of getting stronger but beware of knee pain especially if accompanied by swelling. This is why bike fit and shoe/cleat fit are so important. And also why it's important to "spin" up them (another reason why I don't recommend standing- riders tend to grind their way up standing and it can be really bad for your knees.)

Have fun! I get a great vista at the top of my climb and it makes it all worth while, hopefully, you get some rewards from all the work!

I think it has more to do with cya than anything else.
I have been running that cassette on T660 Deore LX touring hubs, Velocity Dyad, hand built wheel set w/o problems on my Origin8 CX700.
On lots of hills, loaded bike, trailer, chariot child trailer, etc.....
I think potential problems would come in to play in the 29'er setting, off road, running a 22 tooth ring up front. Loads of torque possible.
Not what I am doing with mine, though. 39, 50 teeth up front, here.

I feel exactly opposite, I watch people sitting hills and cringe, standing is just like walking up a steep hill or stairs, a natural position, no unnatural stresses on the knees, sitting... now you're torquing the knees unnaturally, and the hips, when I watch Lance(?) or Alberto on a hill, standing and either keeping tempo or attacking I see balance and strength. Not trying to start an argument, just offering a different view, imho, the two types of riders are~ sit on hills vs stand on hills

Those are fair points, and it's possible that Shimano is simply being conservative, as they are known to be. I'm curious why you're running a 50/39 and 12-36 rather than a 50/34 compact and a 12-34... better front shifting? I was running 50/39 on my main road bike up until recently (changed to a 48/39.)

The kind of standing you're describing (ie. the TDF) takes miles of training to do proficiently, IMHO. I stand on some hills at times, especially really long climbs so my cautions about standing had to do with developing techniques for hill climbing as someone getting used to it. The kind of seated grinding you describe is exactly what I am suggesting the OP avoid. Again, IMHO, I think it's best to develop the ability to climb seated, while spinning, strengthen the legs, get some climbing technique and then, when you want some extra power work on your standing technique.

Since the OP admittedly is not practiced in hill climbing I made the suggestion to remain seated because the kind of error I've seen most often is a kind of desperate alternation between seated pedaling in too high a gear, standing on the pedals for some relief, sitting back down when fatigued by standing and now pedaling in the same high gear at an even slower RPM. All of which is brutal on the knees. By all means, feel free to disagree, ultimately, the OP will develop his own approach to these hills so as many suggestions as possible are probably helpful.

Would be, however many compact doubles will not fit the Origin8 CX700 due to curved chain stays to accommodate super fat tires.
Mine is actually an ultegra triple, minus the inner ring. What I had and could make work with the constraints on this bike. 39 teeth is the fewest I can find for the middle ring......
Changed the cassette to a 12-36 to drop the gearing for pulling my two boys up the hills in austin, although I really don't use this bike for that purpose much anymore.
I could have also replaced the crank set with a deore lx or deore with touring gearing, just didn't want to drop the $ unnecessarily because I already had a new ultegra crank set, rings, and bottom bracket that I could make work for this build.....
I also really like the top end on this bike @ 50/12.......should not technically be possible according to the manufacturer, 48 teeth listed as max chain ring size....

I don't recall ever hearing a warning about using a 12-34 on a road hub, and, I have seen plenty of people do it. I don't think the "massive" torque of one gear inch is going to matter.

I totally agree with you on that. There's so much more muscular engagement when standing.

The OP (and anyone else) is welcome to do whatever they want with their bikes, I just felt like passing the manufacturer's thoughts along. /shrug

Like I said earlier, I think a smaller granny ring is a better solution anyway. That, and getting in better shape if they're considering such low gearing.

I am a hill-o-phobe myself, I see myself in that mr Old Fearing Hills! That might just be my Indian Name. Thanks for writing all that though, I actually found it a little inspiring.

Another thought for 'so much of it is a mind game'. I have young boys (currently 7-12yo) that I am trying to raise right in the cult of cycling, so it is a little bit of a milestone when each of them "finally climbs Fletcher Parkway" or can say "I've conquered Fanita". When I ride loops from the house, I have climbs that destroy me every time. And yet, if I bring a boy along, it's easy peasy. The reason is that I slow down to their speed. So I try to keep perspective in my head, (almost) any hill is climbable. The real limit for me is about 3mph in my 34/34 low gear, any slower and balance becomes an issue. I don't know how to translate that into percentage grade where 34/34 @ 3mph takes my sustainable wattage though. Maybe like 10% or so? I dunno; even though I'm an "Old Fearing Hills" I don't have a good feel for judging grades by eye.

Yes, you're right there. When you stand your muscles are not only doing the work you need to pedal up hill but to support your standing body.

To stand or sit on hills is a much discussed question for racers, tourists and cyclists in general. There is a lot of good information on line about it.

Sheldon Brown has some interesting things to say about it, which may apply to the OP.

I thought about this thread today. I did a long road ride in very hilly country and at the end of a long 3 mile climb, that averaged about 8%, I spun (seated) at a pretty high rpm until just before the crest of the hill, when I shifted up and stood on the pedals and hammered over the top- no doubt its effective and gives power when and if you need it.

I'll repeat that my suggestion is much like what Sheldon Brown suggests- that for the everyday cyclist this may not always be the preferred method of climbing. certainly on those days when you're "feeling your oats" and want to ride like you're in the TDF by all means stand all you want, but for riding to work every day I would suggest learning to effectively climb in a seated position. If you are having problems with a seated position I would check my seat height and bike fit.

Not to mention, the rider, me, apparently isn't putting massive torque on anything hence wanting to drop gear ratios ha!

Seat height was too low, did raise it a bit. Realized it after the first day. Want to know the real kicker? I'm getting transferred across town, opposite direction, almost all flat but 6 more miles. Round trip will be 36 miles, a whole different issue now haha!

the universe is just determined to make you a very fit bike rider with a bike that fits you!