Here is my Aero HB in goat. I collected it in the UK and wore it in a very rainy Xmas period. it sheds water fantastically well.
For me it is the ultimate travelling jacket.
It all depends on how much range of motion you want. The armpit gussets allow you to raise your arms without the whole jacket lifting up and the bi-swing helps a lot when reaching forward.
Whether the gussets are effective or not depends somewhat on the depth of the fold.
for them. I don't like the full action back. What really works great for me are the underarm gussets.I can't say if gussets will be better or not for your purposes but I do know that goat stretches as well as being more supple than horse or cowhide. Goat is most likely the leather that least requires gussets assuming the jacket is properly fitted. Here is a little bit about goat compared to horse from this maker.
Exactly. I’m hoping that the underarm and shoulder gussets will work in harmony with each other.
I wouldn’t count myself in the “clean backs”club though I’d be reluctant to put a full action back on the Sheen since it’d be such a deviation from the style. I’m hoping the shoulder/underarm gusset combination will be more subtle yet still effective.
Do the underarm gussets help at all with reaching forward or just with lifting your arms vertically?Whether the gussets are effective or not depends somewhat on the depth of the fold.
I don't find the short ones so effective that I would give up the clean back
Right. Part of me wonders if goat gussets are overkill though I guess the military didn’t think so. Thanks for the info link. Interesting that they describe horse as stronger than goat while Aero’s site describes goat as tougher than horse when the same thickness.
That’s a beautiful, rich brown!
Good question. Logically, they should only help the upward movement. I have only two jackets with underarm gussets, but with both I can also stretch forward without problems. And that, although the jackets are rather tight. I assume that this is also due to the high armholes.
John Lofgren Monkey Boots Shinki Horsebuttt - $1,136 The classic monkey boot silhouette in an incredibly rich Shinki russet horse leather. 
Grant Stone Diesel Boot Dark Olive Chromexcel - $395 Goodyear welted, Horween Chromexcel, classic good looks. 
Schott 568 Vandals Jacket - $1,250 The classic Perfecto motorcycle jacket, in a very special limited-edition Schott double rider style. Shoulder gussets have elastic bands between the lining and the jacket. Otherwise, the folds would not return to their original shape.
Yea I agree. I don’t really like the idea of having elastic in the jacket. Might just go with underarm gussets after all. Combined with the easy wearing goat, I’m thinking it will still be fine...
What do you need the perfect range of motion for? A sports jacket would probably be more sensible.
