Pavel,
I have found my Brooks saddles -- being largely the result and construction of a natural product (leather) -- vary widely. I have a B.17 in the "sell on eBay" box I carefully re-riveted with Brooks' best copper rivets that looks sooooo fine, but alas, is too soft for my needs. 'Just beginning to dish under my ischial tuberosities (sit bones). My hardest is a B.17 Champion Special in honey-brown belt-leather thickness with skived edges and the "will break, just a matter of when" chrome rails.
I find I prefer a harder B.17 to the softer ones, and tend to sell them just as most people would crave them. Hmm. There may be a market for Danneau's Break-In Service. For those taking note, my favorite is the plain old B.17 Standard. In black. My comments apply to them specifically and Brooks generally.
At any rate, Brooks saddles do vary, Pavel. Some are skewed. Some are made from slightly thicker cuts of leather, according to my digital caliper. Some have barb-wire scars and such that tension the leather, and -- yes! As you suspected! -- the initial bolt tension does vary a bit as well. There isn't a single magical setting, but a "by eye" calculation by the maker. Some are tighter or looser thanks to error aggregation...they are riveted at one extreme or the other of their hole tolerances and so leave the shop more or less taut.
I am a traditionalist, so much so, I mourn the loss of red Proofide, which really was different (and I cannot be convinced otherwise). The white paste that passes for Proofide now is simply not the same, and lacks the exquisite parfum of the original. I've never done drugs, but I swear a person could get high off the original, the smell was that good. But then, I also follow my late maternal grandfather in loving the smell of hot-tar, fresh asphalt, and skunk. Road-kill isn't bad. Go figure.
To hear if such Brooks treatments as Neatsfoot or motor oil causes me to erupt in a deprecating moue of protest, but I do admit it gives stellar results for some and the great number of saddles treated this way indicate it can't be fatal to the leather. Truly, to each his own; if it works for oneself, that's all what matters.
Pavel, I'd be interested in hearing how it goes with loosening the tension bolt. I would hesitate myself, based in my experience re-riveting a number of these saddles (the large copper rivets looked prettier and don't rust, unlike the earlier generations of poorly-plated small steel rivets. They're better now and don't rust, so they get to stay on my recent saddles). When you loosen the tension bolt prematurely and by design, the saddle is de-tensioned, meaning that under the load of a rider's weight, the sides flare. The real trick with a B.17 is to try and keep the sides narrow whilst creating little dishes for your sit-bones. If the saddle flares unduly between the legs, well, it's all over prematurely. Then, Drastic Measures such as hole-punching the sides and lacing them together are called for, else one's thighs will rub and chafe. <-- This is initially wonderful for the ego (Look! I've cycled so much I've developed Sprinter's Thigh!), but is not so great in practice when those same-said thighs begin to chafe and bleed (yes, it happens).
As for water, I am not thoroughly convinced, but I have come to a growing accommodation it may not be as bad for the leather as we might think. My former neighbor, Toshihiko, brought-back from dead a number of secondhand saddles by soaking them in a bucket of water and reshaping them as they dried. It has been about 15 years but as I recall, be de-tensioned them, soaked them, then hung them to dry in a cool-dry place to avoid mildew and mold, binding the sides together at the "neck" (narrow part of the shaft leading to the nose) with old t-shirts (stretchy cotton). When thoroughly dry, he re-Proofided them and was good to go. I wouldn't have laid bets on one old Ideale 90 he found for his Herse replica, but it came out fine. One thing to keep in mind: Wetted (or wet) leather does stretch, but it also dries, so be sure to re-treat it in some way, however lightly.
Also, excess application of any leather treatment leads to stretching and advanced shape-molding well ahead of what would naturally occur, and sometimes (often) it.does.not.stop. It just keeps going, and then one is riding a hammock, not a saddle. This is all something to keep in mind if you prefer a harder, stiffer saddle as I do.
Hope this helps,
Dan.
