Getting better at steep stuff, without a steep wall

So at my local hometown gym (which is very small), both the sport and bouldering walls are pretty much vertical, with no real overhanging sections. This weekend I went out of town and visited a much bigger gym for the first time. The biggest difference was the huge amount of overhanging bouldering, and I was totally out of my element. I could climb near my max (V4-5s) on vertical problems, but when I tried overhanging problems, especially those at 45*+, I struggled badly on V2s and 3s. I guess it's no surprise, it takes a whole new level of technique that I am yet to master, but I noticed I'm just super weak in "body strength" or "body tension" as well. Just had a hard time keeping my feet on the wall. So...
My question is, without having a steep wall to train on back home, how can I train to be stronger on those problems when I get to them? Or is that just really unrealistic? I'd love to make more trips to a bigger gym but during the school year when it's a few hours away it's just not too practical unfortunately.

Front levers on a pull up bar. Nuff said

I’m going to go with “no”, you can’t train for steep overhangs without climbing on them. You can do supplemental exercises and get a strong core, which will help some. But you’ll waste a lot of strength if you don’t practice the technique for overhangs.

As you noted, keeping your feet on the wall becomes vitally important when you’re climbing the steeps. This requires the right body position, good body tension, and higher utilization of twist-locks, drop knees, back steps and flags, heel hooks, toe hooks, sometimes even bicycles. On vertical routes, you can often get away with being very frontal to the wall, without using any turning motion, and just pull really hard (the classic frog position). When you’re climbing the steeps, there are moves that require you to lock off and pull hard, but if you do that for every move, it is very inefficient.

Toeing-in also becomes important when you’re on an overhang. On vertical routes, you usually just stand up on a foot hold by pressing it away from your body. However, on steep stuff you need to dig your toe into a foothold and press it towards the earth (not simply away from your body), and essentially pull your lower body into the wall. This toeing-in, along with keep the right body tension, is what keep your feet on the wall. This is not something you can train effectively on a vertical route, because you just can’t get the feedback if you’re doing it correctly or not.

A lot of people train “core strength” by doing crunches or leg lifts. That may be great for getting a six-pack, but I don’t think they are very specific to climbing. Leg lifts may be useful when you cut loose and need to bring your feet back on the wall, but usually the idea is not to cut loose in the first place, and you need to keep body tension with your body extended in order to do that. That’s not the position your body is in when you do crunches or leg lifts. Mark Anderson put together a blog post on some useful core exercises that also incorporate other muscle groups, most of the exercises require you to keep your torso rigid, which mimic what we do in climbing pretty well.
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