UKH

So Scarpa say the flex on the new Maestrale RS is 125.

Is this on the same scale as piste ski boots?

I figure it should be, and therefore that if I want a piste boots that are a bit more rigid, I need to go to a 130 flex piste boot.

But I seem to recall something somewhere saying it is not directly the same scale, that a touring boot with 125 flex is equivalent to roughly 115 for a piste boot.

Thoughts? 

Thanks.

As far as I know there is no universal rating scale for flex. A given rating can very between manufactures, models etc.  Anecdotally I've also heard that touring bindings are generally softer for a given rating. I guess just need to try them on and get a feel as best you can. 

As Alex said, from what I gather from professional reviews, its all a bit subjective it seems.  Particularly when it comes to how progressive the flex is along its movement.  From what I've read, it seems a lot of touring boots (presumably due to the lighter construction) tend to be softer at the limits of flex.  I.e. they don't stiff up as much.

For what it's worth, last year I got myself touring boots (wanted Maestrales but they didn't fit, so got Fischer Ranger 130s which are pretty similar) and found them a little softer than 130 flex downhill boots, but more than enough to cut up the slopes at speed.  

Got the Maestrales in a 110 flex as my Lange alpine boots are 100 even at 58kg they are nowhere near as stiff as my Lange boots. But they are closer to the weight of a single alpine boot and the range of movement in walk mode is excellent. Hybrid boots which are pin compatible are much closer to the alpine boots they are based on, for anything more than side country they were too heavy for me.

As others have said, flex isn’t a universal index but more to dictate how stiff the model is relative to other models in the brands lineup. I’ve got a pair of Lange RS130 race boots that are miles stiffer than any “130 flex” piste boot that I came across while working as a ski tech and make my Superguide Carbons feel soft. Likewise the Nordica boots tend to come up really soft, whilst the Atomic boots tended to come up stiffer. Best advice would be to find a good boot fitter once shops are open and try a few models.