Ski Mountaineering Crampon Boot Fit

Looking at buying some Sportiva Siderals. I will need to climb alpine ice.

The boot has an asymmetrical rockered sole with very small welts for the crampon bail.

Q: What automatic (step-in) crampon will fit these boots best? Stories? Experience? Wisdom? Do I need to consider something like the Petzl Lynx?

T.I.A.,

I believe this boot is nearly the same but cheaper version of the Spitfire. I have seen some mentions online of people having trouble getting crampons to fit properly on the Spitefire. There is one in the reviews here: www.backcountry.com/la-sportiva-spitfire-alpine-touring-boot

Amigo if you're buying them at a shop best bet is just to fit in person--I think thats the most valuable, either go into US outdoor or Mnt. Shop and mess with what they got there or bring your boots in if you are ordering them from online. If you don't mind carrying a credit card balance for a bit you could place an order from bc.com or such and ask for a free return-shipping label and get 2-3 pairs of crampons and test them yourself and just keep the one that you like/fits the best.  I've been eying the G22 or G14s.

Dane's blog (Cold Thistle) and on Teton Gravity Tech Talk forum has gone over this into the deep end you may be looking for--though not necessarily with that exact boot.

Limited experience old chromolly sabertooths with a toe basket were not happy campers on my garmont ski boots, fit 'ok' but fudged up the rivets for the toe basket.  The camp alu fully autos work like a charm on the garmonts and dynafit ones.  The camp ones Lman got with toe baskets, last time i saw, fit terribly on on his boots (large gap between front points and toe of boot--scarily so imo--hope he was able to tweak it and improve.

Thanks Water.

You can always use straps,
......the French do, and they rock!

Not that I'm old fashioned or anything, but having had automatic crampons torque off in exposed spots makes you into a believer in practicality over technology.

Lynx comes with strap bits too, but in my humble opinion they suck for snice mountaineering as the cylindrical bolt housing at the front prevents good hook-up on snice, & the front points have no significant horizontal component. Technical ice however is great.

My 2 cents, feel free to ignore

i've never seen the siderals in person but just looking at photos online i'd be surprised if they didn't accept most standard crampons on the market.

like jake the brit says, if you intend to climb alpine ice, definitely consider a crampon with horizontal front points. the petzl vasak, sabretooths, or g-12s are good options. (the front panel of the vasak is slightly curved and fits the rocker of my boot perfectly.) crampons with vertical front points like the grivel g22 or g14 are optimized for water ice and mixed climbing and will shear through neve and sun-baked ice. most alpine ice routes in the cascades entail a fair amount of snow and neve climbing. for something like the north ridge of baker you could probably even get away with aluminum crampons, depending on conditions.

in my experience, automatic (toe strapless) crampons work great on ski boots. totally locker fit.