My Orange 224 can for one.. (though it is only advised with correct shock size/adjustment so nothing hits etc) Ive actually tried with a 60deg HA and feels fine as we tend to ride pretty steep stuff where i usually ride. Makes it a lot more stable. I think also suspension setup plays a big part. As i run a tuned Elka shock and it sits very high in the travel so doesn’t sag much initially at all.
Also.. a manufacturers claimed “HA” isnt what usually ends up what it actually is. As soon as you sit on the bike depending on shock setup, sag, your weight etc the bike may sag down considerably more!
eg: most v10’s have a 65.5 deg (i think it is) but because of there design to sag they even themselves out to a more normal rider/HA setup.
One bike which does come to mind is the new Mondraker which you can adjust less than 60deg. And i swear i’ve seen Gee Atherton run something super slack as well..
You're dead right on the 'dynamic head angle' situation, IE once you're sitting on the bike and it's sitting in its sag etc....it's an entirely different ballgame. As you mention the V10 has a 'fairly steep' stock HA (thought it was steeper than 65.5, pre carbon version?) but it's a 10" travel bike so when you're riding it it is considerably slacker, dynamically, than say an 8" bike with the same static head angle.
There are a few production bikes that go super slack, like the Mondraker summum that you mention and the orange, '09 comencals? I doubt Gee's bike is a factory frame though, it always looks crazy slack...and Barel has run some super slack angles in the past....fairly sure he ran 59 at a world cup a few years ago...with 800ish bars? The dude is an experimenter for sure.
Like I said I think the adjust-ability factor that is appearing with the new bikes is fantastic and is the way of the future. But I also think there is somewhat of a 'it's the cool thing to have' factor related to super slack frames. That said it may become the norm, much like 750 bars have become for the most part.
