I currently have two bikes - a Surly Long Haul Trucker set up as a pure road bike with skinny high-pressure tires, and a Trek 820 mountain bike.
I usually ride the Surly, and normally go for 30+ mile rides each Saturday and Sunday. I converted the Trek into a Winter/Bad Weather bike with lights and fenders. I really don't do any "mountain biking" per se, but kind of like the option of the wide low-pressure tires for riding on gravel or other "unimproved" surfaces. Still, most of my saddle time happens on the Trucker.
I've been seriously riding for about 1 - 1/2 years now, and when I got started I had chafing issues from the saddles that came on my bikes. The Trek came with some sort of no-name saddle, and it was the worst. The Surly (custom built at my LBS) had a Wilderness Trail Speed saddle on it, and it was quite a bit more comfortable, but I still experienced some chafing.
Of course I tried all of the various chamios-padded shorts, various lubes and powders, etc.
Then I put a Brooks B17 on the Surly, and all of the chafing stopped.
Yesterday we had some major rain. Every time this happens there are lots of gravel driveways, as well as other debris, that end up being washed onto the roads, and the gravel/mud over blacktop is not real friendly to the 700 x 28 tires on the Trucker. This morning I decided to dust off the Trek and take it for a spin. Before leaving, though, I removed the no-name saddle and replaced it with the Wilderness Trail jobbie that came on the Trucker.
By the time I got back I noticed the start of some chafing again.
I noticed that the Brooks B17 leather is very slippery against one's shorts. The synthetic WTB saddle is kind of grippy. I think what causes the chafing with synthetic saddles is that my shorts stick to the plastic and thus rub against my skin, while with the Brooks the shorts slide against the leather and therefore don't rub against my skin.
I just ordered another B17 for the Trek.
Funny thing, though. I just looked through pages and pages of pics of mountain bikes in the pics thread, and I saw nary a Brooks saddle. With the popularity of Brooks saddles on road and touring bikes, why don't more of the mountain bikers go that way?
Also, due to the restricted hand position on the flat-bar Trek I get some numbness in my hands after 1/2 hour or so, I'm thinking about converting to some other handlebar options. I'm torn between just adding bar ends, or going whole-hog with maybe some Trekking bars. Any suggestions?