Splitboard Mountaineering Hard Boot Sizing

Hey guys I have a question. 

That being, how should hard boots boots fit if I’m going to incorporate ice climbing as well as general riding and touring? 

I got shell fit for a 27 backlands carbon and a 28 backlands carbon. The 27 fit me with 1 finger and a tiny bit shell fit (under 1.5 fingers, maybe like 1.2 or 1.3). The 28 fit me with a nice 2 finger shell fit (snug 2 finger, but not too snug). 

Should I get a 27 or 28? Will heat molding a 27 with an 9mm intuition liners with 2 toe caps and an aftermarket footbed (which slightly increases volume but reduces length slightly) work for the climbing (split mountaineering) as well and give me a better performance on the downhill? 

Or is the 28 the way to go to give a slight bit more space for kicking ice? But what if after I wear out the liner on the 28’s and want an intuition liners, will it work in that shell, since some intuition liners work better with a tighter fit. I could go for a 12 or 15 mm intuition liner though. 

I didn't try the 27 on with the liners in, only shell fit. The 28 fit me well with the stock liners in. When standing straight my toe was just pressing into the front, and then when I bent my knees to a riding position, my toes just pulled off the front (were barely grazing the front). But what would happen with a heat mould and a footbed? 

I eventually want to have a quiver of boots, one for touring and riding, and one for split mountaineering. Would it make sense (not financially, just optimality wise) to have a 27 in either a backlands carbon, Pierre Gignoux Black Snowboard, or maybe a SplitPin make sense for only touring and riding and no climbing? Or does it sound like the fit for the 28 is adequate and would work with 12 or 15 mm liners for this purpose as well. I am unsure of the exact stock linker thickness on a pair of Atomic Backlands Carbon Boots.

I am a bit lost in all of it right now lol, so I really appreciate any and all help!

Thanks!

I ski tour a lot (including plenty of time in crampons), but I don't splitboard, and I don't climb waterfall ice in my ski boots.  Only steep snow and neve.  With that in mind...

Atomic Backland Carbons will have a thin stock liner.  I'm not sure how thin, but all of the lightweight ski boots come with pretty thin liners.  

I'd personally go with the 27.  A bit more than 1 finger shell fit seems pretty good.  If you mold a thin aftermarket liner (like the Intuition 9 mm or a Palau Tour Lite) with toe caps you should be OK.  Although it's hard to say until you try them on with your aftermarket foot beds.  Instep fit is hard to determine until you put them on and walk around a bit.  No reason you can't mold the stock liner as well and see how it rides before buying an aftermarket liner.  And any reason you're limited to the Backland?  Plenty of other light boots that would be suitable for hard booting.

2 finger shell fit is pretty big.  You're more likely to swim around, which could actually lead to more toe bang (plus heel lift and general slop for riding and climbing).  

Unless you're heading to Denali or some other very cold high elevation environment, I think it's generally a bad idea to try to take up excess volume with a thick liner in a shell that doesn't fit properly to begin with.  

Edited to add: I have splitboard buddies who use hard boots in the spring when they're doing a lot of booting/crampon work etc. but they use soft boots to ride pow and for day-to-day mid-winter touring when you're not using pointy things.  Obviously that's a much bigger investment but if you live in the mountains and ride a lot, it's not unreasonable.  And there's plenty of folks who get rad shit done using only soft boots (see Jeremy Jones and Nick Russell).

As a former hardbooter to skier convert you’re running into a sticky situation. A lot of people like to use ski boots to climb because they lack heel flex, some people climb in ski mode. I’d look at the key equipment disruptive’s if you want a beefier ski like boot.

In response to your actually question I’d be concerned about too much space on the toe unless you keep them buckled down / have a good footbed that keeps your foot in place. I’ve kicked off my big toe nails borrowing a pair of boots that were too big. Idk if any of this helps but if you’re sold on the atomics see if you can buy a pair used in 27 and then try them out. A quiver of one is hard and hard boot split boarding is even more niche.

That being said I have a friend who guides on rainier and uses the phantom slippers so you might have to be the guinea pig for all of us.

https://cripplecreekbc.com/products/key-equipment-disruptive-hardboot?variant=43945385918621&country=US&currency=USD&utm_medium=product_sync&utm_source=google&utm_content=sag_organic&utm_campaign=sag_organic&utm_campaign=gs-2019-05-06&utm_source=google&utm_medium=smart_campaign&gad_source=1&gbraid=0AAAAADts0Nng6f1PcFWgUHgYQbwPFrA0-&gclid=Cj0KCQiA-aK8BhCDARIsAL_-H9kJzPAwOGNz1XdHeWoNvlFj-TxKlMkSHeJAhfzFyWG240lCApsK1TQaAhwsEALw_wcB

So, I have a pair of 27.5’s Burton Ion Step on boots. I had them heat molded, albeit without toecaps, but they are very tight, even with aftermarket footbeds. I am unable to comfortably fully extend my toes in them with liners in, meaning that in order to do so I have to press hard into the front of the liner with my toes. And my toes are slightly curled when riding. I will try to mold them again with 1 or 2 toecaps this time.

Anyway, I know that sizing varies vastly from brand to brand and sometimes even model to model in the same brand, but I figured that I would run into a similar issue with the hardboots for split boarding, since the shell fit on the Ion’s and Backlands, both in a 27 felt pretty similar. I realize that I can run a thin 9mm intuition liner and heat mold with 2 toe caps, but I don’t know if it will be enough. That was my main aversion to the 27.

And I knew someone who was selling a pair of brand new Phantom Slipper HD’s in a 28 (the guy who shell fit me). I got shell fit in Atomic Backlands, but that’s fine because the Phantom Slipper’s are built on that platform. I picked them up just to be safe since Phantom is no longer making boots, and I can always try selling them later. But what do you guys think?

His reasoning was that for kicking ice the 27 would be too tight and I might run into some problems with loosing toenails and stuff. The instep fit seemed fine in both 27 and 28.

I know that the 2 finger shell fit could be a bit tighter, but even with stock thin Phantom liners, my toes are just pressing to the front when standing straight up and are just grazing when in riding position. This is without a heat mold or footbeds though. So it’s a bit of a tricky situation and honestly it’s beyond my boot knowledge and experience, so that’s why I came to the internet lol.

I did get fitted at SKIMO Co in SLC Utah, so it was a place that specializes in lightweight touring equipment. And the guy who fit me was a main resident splitboarder and a guide, who regularly does split mountaineering objectives in the Wasatch range and beyond.

So you have a 28 phantom slipper already? If it were me, I'd just roll with that for a bit and tour a bunch to see how it feels. If you go to a smaller shell size like a 27 and need to mold the boot longer, make sure you bring your bindings with you to the boot fitter as there will be a limit to how far you can stretch the length of your boot without interfering with your toe bails on your bindings... Think max 2-3mm maybe? (at least with a phantom setup, I don't know about the sparks)

For reference, I'm in a 29.5 original phantom slipper and have US 12.5 sized feet / 46.5 Euro. The shell is 318mm. These fit me comfortably, a very small amount of extra length for the toes. The stock liner is super thin, I switched to an intuition tour wrap liner... think the 9mm. I notice a dramatic improvement in riding quality by doing this. The boots were already responsive, but the intuition liner filled in any extra void space and was just a much more comfy, softer feeling setup especially when riding on variable terrain.

I have not used the slippers for waterfall ice climbing, I think they would be pretty good as Phantom moved the ankle strap back to the pivot point of boots so that it mimics where a soft boot strap would be placed. When tightened, this sucks your heel very effectively down and backwards to the heel pocket. I don't think many ski boot's lower straps do this to the level the Phantom does.  I'd be totally happy using these boots for neve and the occasional stepped slabby ice section, but I would thoroughly vet these on top rope before leading waterfall ice with them.  

I've had several pairs of Atomic Backland boots over the years and typically I have sized mine down aggressively to reduce toe and heel drag when snowboarding.  My wife ended up with a pair sized up slightly and has gone to Intuition medium volume Tour liners and is much much happier than she was with the stock (sock) liner.  I'm not convinced that sizing them down is the right answer for splitboarding since we could actually use a bit more lateral and medial compliance than a skier.  A little extra room and foam in the heel pocket of the boot is more comfortable when shredding.  I mix my modes of travel between splitboarding and skiing and right now I think I'll try Backland XTDs in the softest women's version as my next split boot.  I'll take a little more weight as long as I have a good fit and great range of motion in the ankle when touring and the softest women's version is something like a 95 flex and comes up to a size 27.5 which happens to be the size I fit in.

The great thing about the Atomic boots is that you have a lot of capability to stretch the shell out by cooking the shell in an oven similar to molding the liner.  My boots look like marshmallows by the time my boot fitter is done with them and they end up more comfortable than my LaSpo Nepals.  It makes it easy to size down.

Since Atomic moved the buckle from the side of the foot to the top of the foot I prefer the buckle closure instead of the Boa on the lower foot.  The first version of the buckle was on the side of the foot and would open up when walking in breakable crust.

I was told by the boot fitter that molding the boot length wise wouldn’t be ideal since it would impact binding and crampon fit/integration.

Trust your boot fitter but also know that they are probably not familiar with splitboard binding systems and the different ways that you pressure your foot in a boot when snowboarding instead of skiing.  

My feet measure 283mm right and 285mm left and I wear a 27.5 shell with the most drastic shell modification at mid-arch for my navicular bone (flat arch, really wide mid foot).  I also ski in the Backland XTD and the Hawx Ultra XTD both in 27.5 and climb in LaSpo Nepals and Trango Techs both in a size 45 just to give you a bit of extra boots to compare sizes against. I had one pair of Backlands in a 28.5 shell and it was still too narrow in my mid foot but I was swimming in it everywhere else, it felt too long.

I'm tempted to try an Intuition liner in my Backlands to get a little more lateral travel and cushioning around my heel when snowboarding.  The stock sock liners aren't very good for shredding.

The boot fitter was an avid splitboarder and a splitboard guide.

You're probably in good hands then.  My bootfitter is not a snowboarder but he has listened to my feedback and worked with me on many pairs of boots.  I happen to be a splitboard guide, I'm not sure that makes me any more knowledgeable on fitting other people's feet beyond my own but I can at least share my experience using my boots in a variety of terrain.  I come from a competitive snowboarding background.