Originally Posted by Bob the Mech

Saddle fiiting:

1) On line research and reviews.
2) Buy one on line, ride with it and hope it won't cut you in half.
3) Buy one from a good LBS which will provide a saddle fit service, ride with it and still hope it won't cut you in half.
4) Already have a well fitted saddle and make sure your next saddle is 'like for like' or that the lenght, width, shape (waved, flat, cutout etc) are as near as damn it.
5) Make sure your cycle shorts padding is up to scratch...the best fitting saddle in the world can't compensate for poor designed chamois padding (like riding 6 hours in bibs designed for 2-3hrs of butt pressure...).
6) Years of riding...sometimes you just know what will work for you just by looking at it...like some kind of Jedi Saddle Master...
7) Impulse buying a saddle because it's the lightest, most technically advanced perch...ever...and it will make your bike look 'way cool'...NO, just no...

Disk pad replacement:

Parktool recommend changing disk pads at 1mm and less of pad material...the thickness of three business cards apparently