I'm designing a custom 29er frame primarily for endurance racing & multi-day stuff (so, all-day comfort is important), but also something that's still going to be fun for short singletrack blasts and useful for XC racing. I'm pretty sure about most of the dimensions, but thought I'd sanity check (is there any sanity on STW?!) my idea on head tube angle. I don't like a really twitchy ride that I think some 29ers can suffer from. In particular I don't want to feel like I'm going to be pitched over the bars on steep technical descents & small drops, but of course I still want it to go round corners. With that in mind, I'm looking at a 70.5 degree HA with 470mm axle-crown rigid fork (45mm offset) or sagged 80mm Fox F29 suspension fork. Also thinking something like a 105mm head tube (this is on a 17.5" / medium type frame size).
70.5 degrees seems pretty slack by 29er standards (or perhaps it isn't?), but from what I can tell I *think* it's what I want. Any thoughts before I make an expensive mistake? Cheers!