La Sportiva Solar II Alpine Touring Boots

The shell and cuff of the Solar II Boots are made with Pebax Rnew which is a bio-based polymer that's lightweight cold-resistant and provides a combination of toughness and flexibility.

La Sportiva has integrated a BOA Fit System over the forefoot of the Solar II Boots to save on weight and provide a micro-adjustable fit that is quick and easy to use. The BOA wire connects the tongue to the shell and is able to compress the boot over a wide area of your forefoot. These strong yet lightweight cable laces are routed through three low-friction lace guides for an almost instant fit. Thanks to the cable lace's innovative routing pattern your foot is subtly pulled back into the heel pocket of the boot for an impressive fit.

On the spine of the Solar II Boots, you’ll find an innovative and patented ski/walk mechanisms that La Sportiva calls their Swing-Lock Closure System. Instead of the traditional vertical locking arm, the Solar II uses a swivel rotation design that provides a fast and secure closure while limiting the external stresses on the mechanism and its exposure to snow and ice buildup. When open in walk mode, the Swing-Lock Closure System provides an impressive 68° of cuff rotation, allowing for maximum freedom of movement. This is helped by La Sportiva’s EZ 3D Flex Tongue which is also made from bio-based Pebax Rnew and connects the upper and lower boot with an overlap cuff system for a custom fit.

Above the Swing-Lock Closure System, you’ll find a removable spoiler which allows you to easily adjust the boot’s angle of rotation. By adjusting the height of the spoiler the angle of inclination is either increased or decreased—La Sportiva calls this their Progressive Grade System.

In order to secure the Solar II’s cuff there is a traditional micro-power strap along with what La Sportiva Calls their Easy To Wear System. This consists of a velcro strap and buckle that you can fine-tune your fit with and to facilitate easy on/off of the boots there is a quick-release tab to quickly disengage the entire strap from the cuff, which provides a more generous opening for your foot.

Under the Solar II Boots are La Sportiva’s Grip-Guard Outsoles which have abrasion-resistant inserts in the heel and toe. The soles of the Solar II’s are rockers and of course, have integrated tech fittings.

• EZ 3D Flex Tongue is Pebax® Bio-Based Rnew® 1100
• Cuff is Pebax® Bio-Based Rnew® 1100
• Liner is Thermomoldable High-Density PEE & Open Cell Low-Density PU with Flex Inserts
• Sole is La Sportiva Grip Guard™ (complies with ISMF standards)
• Buckles and closures are SWING-LOCK Closure System™/ BOA® Fit System / Easy 2 Wear Closure System / Optional power strap

• 3 forward lean positions of 12°/14°/16°
• 68° Range of Motion
• WarmSole™ Insert is a removable insole made of insulating polyurethane.
• Power Strap
• Swing-Lock Closure System allows fast and simple lock-out
• Pebax® Bio Based Rnew® 1100 shell and cuff provide a stiffer flex than the ultralight weight suggests
• La Sportiva Grip Guard™ Sole provides needed traction for walking perilous ridge-lines
• Ez 3D Flex Tongue™ with BOA® Fit System with the joint between the upper and lower sections, as well as Overlap System, customize the fit
• Progressive Grade System™: Quick forward lean boot angle with adjustable height spoiler insert

Having not skied the previous Solar Boots, I cannot comment on how the new Solar II compares for fit and performance but I can say that it more than holds its own when stacked up against other lightweight AT boots such as those mentioned below at the end of this verdict. Straight out of the box, I found the Solar II Boots to be very comfortable with a roomy toe box and a firm foothold thanks mostly to the BOA Fit System. The liners were adequately padded which is not the norm in most lightweight touring boots as this is typically where I see a lot of brands cut corners to shave off grams. While the BOA Fit System does save on weight when compared to the previous forefoot Spider Buckle Evo it doesn’t give up any performance or foothold. I was able to micro-adjust the dial to find the sweet spot for my feet and also reef it tight when I needed to maximize support for more challenging skiing. The top buckle/power strap is an innovative take on traditional velcro straps in that it is a set-it-and-forget-it operation. Once the desired tension is achieved the velcro does not need to be reset as the attached buckle provides all the leverage to close the cuff and firmly hold your foot/shin in place. For easy in and out of the boots, this top buckle can be opened and the pull tab on the other end of the strap can be unhooked so that the strap is fully released—brilliantly simple.

With a flex rating of 90, the Solar II Boots provide a somewhat stiff flex relative to their weight, but for more advanced and hard-charging skiers you may find yourself asking for more. In deep pow and hero runs the Solar II Boots perform exceptionally well, it’s only on steeper more technical terrain or when the pow gives way and I was confronted with chunder and broken crud that I found I was maximizing the flex and wanting more rigidity. Thankfully this is more than made up for in the boot's weight and insane 68° of cuff rotations.

The patented Swing-Lock Closure System is very intuitive to use and provides a much more rigid closure when in ski mode than traditional mechanisms. Climbing on the skin track is effortless although there is some noise and friction from the overlap design but not anything that compromises the experience. The best part of the cuff rotation is that you don’t need to unbuckle or loosen the power strap in order to enjoy the full range of cuff rotation. Like most other La Sportiva boots I’ve reviewed the Solar II is a 'buckle it at and forget it' kind of boot—set the buckles at the trailhead and don’t fuss with them until you are done your day.

The Solar II boots ski really well, the flex is fairly progressive with only minimal shell bulge and they are able to drive skis in the 100mm range. It was only when encountering less-than-ideal conditions that I ever had to really focus on the task at hand to get the boots to deliver the power I needed.

Overall the Solar II Boots were comfortable with impressive foothold and skiability considering their weight, they of course walk uphill with little effort and will not impede your thirst for vert. Other lightweight alpine touring boots that you might also want to consider would be the Scarpa F1 XT Boots, Tecnica Zero G Peak Carbon Boots, Dynafit TLT X Boots, Atomic Backland Carbon Boots, Dynafit Radical Pro Boots and the Dalbello Quantum Free 110 Boots.