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La Sportiva

La Sportiva Mens G5 Mountaineering Boot

La Sportiva Mens G5 Mountaineering Boot

£472.50 £525.00
10% off

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The G5 is an ultra technical, stiff, waterproof and quick drying boot designed for high altitude mountaineering and working outside in freezing temperatures. A layer of insulation keeps you warm while a low volume reduces weight.


Season : 2020W R

Code : SP21C9991-

Weight : 0KG

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The G5 is an ultra technical, waterproof, B3 rated, insulated boot designed to be used for high altitude mountaineering and working in sub-zero temperatures. The G5 is comprised of two layers; the inner boot and an outer shell. The inner is a 4-layer insulating design which features a waterproof Cordura membrane to keep your feet warm and dry, an insulating felt, an insulating polyethylene barrier and an abrasion resistant, breathable mesh. These 4 layers combine to provide warmth, comfort and protection while in freezing, wet conditions. Providing further insulation is a Carbon insulated 3mm thick footbed; this thick footbed insulates you from the cold but also increases comfort for all day use. 

The way this boot is constructed is in many ways similar to an insulated glove. The inner provides the comfort and warmth, while the inner provides a protective and durable shell. The G5's outer shell (or gaiter) is made from a super tough Cordura stretch fabric which is waterproof, abrasion resistant and perfect for mountaineering boots due to it's low weight. Durability is further enhanced by a 360° rubber rand which wraps itself around the entire lower half of the G5, offering exceptional abrasion resistance and overall durability.

Zip away the outer shell and you reveal the inner boot's BOA lacing system. BOA ditches the classic lace technique and replaces it with a durable wheel. When you twist the wheel on the leg of the boot, it tightens a series of laces which thread their way down the boot. It's primary function is to allow you to tighten, adjust and perfect your laces without having to take your gloves off to tie a bow. Another benefit to a BOA lacing system is that the wheel will tighten the whole boot all the way down to the toe area, meaning a snug, accurate feel is only a few clicks away. 

Increasing vital comfort is La Sportiva's Flex Zone technology. When you think of B3 rated boots, your mind probably jumps to heavy, stiff and uncomfortable (but essential); however the collar of this boot has been designed to flex freely forward and backwards, but still maintain it's rigidity and support side to side. Essentially, you get the best of both worlds, stiff and supportive during side motion, flexible and comfortable during walking motions. Further increasing stability and support is the ultra grippy Vibram Matterhorn sole with Braking System lugs. The sole uses various sized lugs and a sharp heel to dig into the ground while descending. 

  • Waterproof and stretchy Cordura gaiter
  • Highly abrasion resistant
  • 4 layer insulating inner boot
  • Warm and protective
  • Ideal for freezing temperatures
  • BOA lacing system provides a snug fit
  • Waterproof zips
  • Vibram sole with braking system
Care & Advice

Here at Trekitt we know all too well of the difficulties people face when purchasing footwear online. The hardest part is being confident that you have picked the correct fitting footwear, so that is what we will cover in this blog (or if you prefer you can CLICK HERE to watch our video).

In our Hereford shop we offer a professional boot fitting service where we assess your feet, find a selection of boots that match you foot shape and most importantly we make sure that they are comfortable. This is easy to do in the shop, where we have access to the right tools, the option of letting you try on as many styles as you like and a knowledgeable member of staff that can communicate directly with you regarding your needs.

But let’s not dwell on what you don’t have, instead we shall teach you how to ascertain your size using some common household objects.

What you will need:

  1. A piece of A4 paper
  2. A pen or pencil
  3. A floor and a flat wall
  4. A ruler or tape measure

What you need to do:

  1. Put on the socks that you intend to use with the footwear you have selected
  2. Place the paper/cardboard on the floor with one end flush against a wall
  3. Stand on the A4 paper with your heel pressed firmly against the wall and your foot pointed forward with the edge of your big toe aligned with the edge of the paper.
  4. Draw a line just in front of your big toe
  5. Measure the distance from the wall edge of the paper to the line you drew
  6. Repeat the process for the other foot
  7. Finally, check the longer of the two measurements against the table below to find your size
Your measurement (cm) UK Size EU Size
21.7 3 35
22.1 3.5 36
22.5 4 37
22.9 4.5 37.5
23.3 5 38
23.7 5.5 39
24.1 6 39.5
24.5 6.5 40
24.9 7 41
25.4 7.5 41.5
25.8 8 42
26.2 8.5 42.5
26.6 9 43
27 9.5 44
27.4 10 44.5
27.8 10.5 45
28.3 11 46
28.8 11.5 46.5
29.2 12 47
29.6 12.5 47.5
30 13 48
30.4 13.5 49

NOTE: The above table is only a guide. Manufactures don’t like to make it easy as every single one of them strays from the measurements above.

So, once you have received your chosen footwear please take the time to do these simple tests to check they are actually the right size and that they fit the rest of your foot correctly.

The length test

  1. Whip out the removable footbed from the boots.
  2. Put them on the floor about shoulder-width apart.
  3. With your socks on, stand on the footbeds making sure that your heels are right to the back of the heel cup.
  4. You should now be able to see approximately 2 cm (about an index fingers width) of the footbed poking out in front of your toes.

If you can see this amount of space then you are pretty much on the way to making sure that your boots are the correct size. This space between your toes and the end of the footbed ensures that you will not stub your toes on the inside of the boot when you descend. This can be excruciatingly painful. If you can’t see this amount of space then it’s a good bet that the boots will be too small.

The heel lift test

This test will tell you if the shape of the internal heel cup matches your heel to ensure it holds you securely, especially when ascending steep ground. We are trying to eliminate the dreaded heel blister.

Before you commence this test it is imperative that you have laced the boots correctly.

  1. Tap your heel so it’s as far back in the boot as possible, being sure to keep your foot at a right angle to your leg at all times during the next few steps.
  2. Make sure that the laces have no slack in them across the forefoot by starting at the front of the boot and working the slack backwards and to the top. You should just be able to squeeze the end section of your finger under the laces, not easily, but just about.
  3. If you are wearing shoes then ensure the last upper part of the lacing is tight, not cutting off your circulation tight, but certainly comfortably snug as this will hold your heel back in the heel cup and will reduce any excess slipping (If you are wearing boots, this will be the eyelets that sit just below/inline the ankle).
  4. Please also make sure when trying out boots that use all the lace hooks, don’t be tempted to leave the top one undone as your foot needs to be held securely right in the back of the boot.
  5. Now that your boots are done up properly stand up on your tiptoes and walk on the spot on the balls of your feet as if you are walking up a steep hill. If your heels lift more than approximately 5mm from the footbed you may need to pull the laces tighter, or the boots may just be the wrong shape for you.

The toe wiggle test

This test is designed to check whether you have enough room around your toes. Your toes need to be in a happy place, they need plenty of room to wiggle without being squashed together, or cramped in from above. However they don’t want to be swimming around in acres of space either, this will cause friction blisters and stability problems when traversing hillsides. So, with the boots done up properly, walk around your house and make sure that your toes can wiggle freely.

Home Trial Period

However, even after the most rigorous assessment and testing, there is no better way to be absolutely sure than to have the boots on your feet for an extended period of time. We therefore offer our Home Trial Period which gives you the opportunity to wear the boots around your house to give you an indication of how they feel before you venture outside. We recommend that during the Home Trial Period that you wear the boots for as long as possible and at different times of the day, wear them up and down stairs, when moving around and when resting, you can even sleep in them if you want. 

IMPORTANT NOTICE: During the Home Trial Period we insist that the boots are worn indoors only. All footwear must be returned in a new and perfect condition with the original packaging and a proof of purchase. We retain the right to refuse to refund or exchange if footwear shows any sign of being worn outside.

For full details on footwear aftercare please check out our related blog here.

Technical Information

protective outer shell consists of a Cordura® stretch, water-repellent and anti-abrasion + functional, stretch fabric + waterproof membrane 

Inner Shell:
4 layer insulating structure: waterproof Cordura® + insulating felt + insulating polyethylene barrier + abrasion resistant, breathable mesh

Lacing system:
Velcro at the top, Boa quick lacing system at the bottom, external, waterproof zip

Carbon insulation, Honey-Comb Tech 3mm

2mm Polyurethane with different thickness on the toe and heel for crampon compatibility 

Vibram® Matterhorn with Impact Brake System lugs

Sizing Information
EU Sizing UK Sizing 
41 7.5
42 8
43 9
44 9.5
45 10.5
46 11.5
47 12


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La Sportiva Mens G5 Mountaineering Boot

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Excellent customer service. Really detailed easy to understand product descriptions on the Trekitt website, and gear reviews on the Trekitt YouTube channel made it so easy to choose the right backpack for me.
Emily - May 2020
Amazing service! Very helpful in regards sizing and what most matched my needs, despite this being done over the internet. YouTube videos of products being examined are very useful also. Would definitely use again, very fast and efficient delivery. Brilliant! Highly recommended!
David R - April 2020
Highly recommend. I usually go to the shop in Hereford as staff are alwasy very helpful and knowledgeable. So this was the first time I have purchased online and the service was just as good as the shop.
Grizzy - April 2020


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