Originally Posted by samurai
...that does NOT mean that most people should mount anything +2 or -1 or whatever based on someone's review. Foot size/BOF is the second main factor after knowing exactly where the ski's center-balance-point is.
If people really are concerned about where to mount, please take the time and do it right. It's not about reading 10 reviews and finding your mounting spot. It's all about matching your BOF with the ski's center-blance-point. And it's not nearly as difficult as many assume if it is broken down and simplified in that manner.
Not based on random reviews...
More and more skis, especially twins, are being marked with a range. You get to pick where within the range to mount based on preference, your size, etc. The Mantra should probably be marked in this way.
If you poked around enough, you might find that the 1 - 1.5 back suggestion for certain riders and uses just might be endorsed by your local Volkl tech type folks. One of my kids just had his Mantras mounted 1 back - after our favorite shop checked with their connections at Volkl. The other has been skiing his 1.5 back for a year based on comments at TGR and here. He's got railflex bindings & could move to the mark - if he wanted to...
As for the BOF common wisdom, this might deserve a thread of its own - but I'm pretty skeptical of the whole BOF on center of "running surface" thing at this point. Today's skis vary greatly in any number of parameters. The nature and placement of sidecut. Degree of taper (some "conventionally shaped" powder skis today can have as much as 25 or 30mm of taper...). Flex characteristics. Etc. My strong suspicion is that the BOF on center of running surface is an old carryover that today is more superstition than justified by any engineering reality. I'd love it of someone with appropriate engineering knowledge could explain to me why my intuition on this is wrong...