Factor 1 Base Layer Leggings

Factor 1 Base Layer Leggings are one of the best lightweight thermal underwear ranges for general outdoor use.

These thermal leggings are manufactured from stretchy tubular 100% polyamide ribbed fabric with a hydrophilic treatment for superior moisture management.

The extra generous waist heights on these leggings help to prevent lower back exposure and give extra thermal protection to your kidneys. The waist itself is constructed with an internal strong rubber elastic core that is seamed over with Factor 1 fabric for a low profile. The double layered fabric gusset provides added thermal protection around the groin, whilst the ends of the legs have flat ankle seams that help to reduce pressure exerted from walking shoes and ski boots.

These base layers cross over in to anything from, skiing, through to hiking and camping, and can be used in combination with Sub Zeros Factor 2 mid layers for extra warmth in extreme conditions.

Please note: These are end of line garments. There may be some slight colour variations where they have been folded, and some may have different versions of our logo, but apart from this these base layers are perfect. We have greatly reduced the price to reflect this. Our Factor 1 Plus legging has superseded this design. 

Scroll down the page for further product details, technical information, sizing, shipping and any washing instructions.

Size
Color

$22

Only 13 left in stock.
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  • Super soft polyamide fabric
  • Lots of stretch
  • Generous waist height
  • Lay flat waistband with elastic internal core
  • Double layered gusset
  • Flat ankle seams
  • Easy to wash
  • Quick to dry
  • Brand: Sub Zero
  • SKU: SZF1BJ
  • TOG: 0.42
  • Fabric: 100% Polyamide
  • Average weight: 130g / 4.6oz
  • Fit: Snug
  • Layer: First - next to the skin
  • Size availability: XSmall-XXLarge
  • Colour: Khaki, White, Black, Cobalt blue
  • Fabric treatments: Hydrophilic wicking management 
  • Made in: Great Britain

SIZING GUIDE
There are no standard sizes for clothing, which is why each brand has their own unique cut and fit. Please do not presume you are the same size between brands for a similar product. If you have a pair of base layer leggings that fits correctly, then use it as a template for these measurements.  

HOW TO MEASURE
Waist - Measure the full circumference of your torso above the hips
Inside Leg - Measure from the top of your groin down the inside of your leg to the ankle bone. 

BASE LAYER FIT
Our base layers have a lot of stretch, so they will contour to most body shapes when worn. You should wear them close fitting but not so they are restrictive. Wearing baggy or ill fitting base layers will lead to the loss of heat and a reduction in their wicking properties.

Please be aware that the inside leg measurements are taken from the garments unstretched. The waist measurement indicates the range of fit. 

We produce our leggings in two versions, with a fly opening and without a fly opening.  The fly is constructed from a double thickness pouch.  

The table below shows the garment measurements for our Factor 1 base layer leggings. There is a tolerance of +/- 5mm.

SIZE WAIST INSIDE LEG WEIGHT
No Fly
WEIGHT
With Fly
cm in cm in g oz g oz
XSMALL 66-71 26-28 61 24 105 3.7 120 4.2
SMALL 74-79 29-31 66 27 115 4.1 130 4.6
MEDIUM 81-87 32-34 71 28 125 4.4 140 5.0
LARGE 89-96 35-37 76 29 135 4.8 155 5.5
XLARGE 97-102 38-40 81 30 150 5.3 170 6.0
XXLARGE 104-107 41-42 84 31 165 5.8 185 6.5

We ship worldwide using Royal Mail & UPS. All UK orders over £35 are shipped free of charge.

For more information regarding our shipping, including charges and estimated delivery times, please visit our Shipping Page

If you are unhappy with your purchase, please return it to us within 180 days of receipt. To be eligible for a return, your item must be in the same condition that you received it, unworn or unused, with tags, and in its original packaging.

For more information regarding our returns policy please visit our Returns Page

Washing instructions for Sub Zero base layers are printed on a white silk tag stitched to the back neck and can also be found knitted in to the waist band. Please follow these instructions carefully as failure to comply with them will make your guarantee void. If you have removed the tag or are unsure of the washing symbol meaning, the full washing instructions can be found below.

  • Machine wash or hand wash in water not exceeding 40°C or 105°F
  • You can use a mild washing detergent but ideally you want to use a base layer specific washing treatment 
  • Wash dark colours separately, do not bleach, do not use fabric conditioners
  • These base layers can be spun dry in a washing machine
  • Do not tumble dry. These base layers will quickly dry on a line or airer as they retain very little water once spun/rung out. 
  • Do not dry clean
  • Regular ironing may be performed at a low setting (110°C, 230°F) only, but we advise against it.

 

GENERAL WASHING TIPS
When you go to wash any garment with a zip, ensure it is done up fully otherwise the exposed teeth may cause harm in the wash cycle. The same can be said for garments containing Velcro. Your best course of action would be to wash these garments either by hand or on their own in a washing machine.

With the advancement in detergent technology, you very rarely need to wash any garments these days above 30°C. It is better to use a specific anti-bacterial wash-in treatment rather than increasing the temperature.

A lot of Sub zero products, especially the base layers and mid layers, can be ironed on a low temperature setting. We would advise against this as the heat settings on irons are not always reliable. In any case, the stretch properties of synthetics helps reduce creases in the wash and if there are any afterwards, they often drop out when worn.

Like most synthetics, Sub Zero fabrics will melt or burn if exposed to flame or direct heat. They are not flame resistant; do not use them near ANY direct source of heat or flame. This includes some of our merino wool products that contain a small percentage of synthetic yarn.

  • Super soft polyamide fabric
  • Lots of stretch
  • Generous waist height
  • Lay flat waistband with elastic internal core
  • Double layered gusset
  • Flat ankle seams
  • Easy to wash
  • Quick to dry
  • Brand: Sub Zero
  • SKU: SZF1BJ
  • TOG: 0.42
  • Fabric: 100% Polyamide
  • Average weight: 130g / 4.6oz
  • Fit: Snug
  • Layer: First - next to the skin
  • Size availability: XSmall-XXLarge
  • Colour: Khaki, White, Black, Cobalt blue
  • Fabric treatments: Hydrophilic wicking management 
  • Made in: Great Britain

SIZING GUIDE
There are no standard sizes for clothing, which is why each brand has their own unique cut and fit. Please do not presume you are the same size between brands for a similar product. If you have a pair of base layer leggings that fits correctly, then use it as a template for these measurements.  

HOW TO MEASURE
Waist - Measure the full circumference of your torso above the hips
Inside Leg - Measure from the top of your groin down the inside of your leg to the ankle bone. 

BASE LAYER FIT
Our base layers have a lot of stretch, so they will contour to most body shapes when worn. You should wear them close fitting but not so they are restrictive. Wearing baggy or ill fitting base layers will lead to the loss of heat and a reduction in their wicking properties.

Please be aware that the inside leg measurements are taken from the garments unstretched. The waist measurement indicates the range of fit. 

We produce our leggings in two versions, with a fly opening and without a fly opening.  The fly is constructed from a double thickness pouch.  

The table below shows the garment measurements for our Factor 1 base layer leggings. There is a tolerance of +/- 5mm.

SIZE WAIST INSIDE LEG WEIGHT
No Fly
WEIGHT
With Fly
cm in cm in g oz g oz
XSMALL 66-71 26-28 61 24 105 3.7 120 4.2
SMALL 74-79 29-31 66 27 115 4.1 130 4.6
MEDIUM 81-87 32-34 71 28 125 4.4 140 5.0
LARGE 89-96 35-37 76 29 135 4.8 155 5.5
XLARGE 97-102 38-40 81 30 150 5.3 170 6.0
XXLARGE 104-107 41-42 84 31 165 5.8 185 6.5

We ship worldwide using Royal Mail & UPS. All UK orders over £35 are shipped free of charge.

For more information regarding our shipping, including charges and estimated delivery times, please visit our Shipping Page

If you are unhappy with your purchase, please return it to us within 180 days of receipt. To be eligible for a return, your item must be in the same condition that you received it, unworn or unused, with tags, and in its original packaging.

For more information regarding our returns policy please visit our Returns Page

Washing instructions for Sub Zero base layers are printed on a white silk tag stitched to the back neck and can also be found knitted in to the waist band. Please follow these instructions carefully as failure to comply with them will make your guarantee void. If you have removed the tag or are unsure of the washing symbol meaning, the full washing instructions can be found below.

  • Machine wash or hand wash in water not exceeding 40°C or 105°F
  • You can use a mild washing detergent but ideally you want to use a base layer specific washing treatment 
  • Wash dark colours separately, do not bleach, do not use fabric conditioners
  • These base layers can be spun dry in a washing machine
  • Do not tumble dry. These base layers will quickly dry on a line or airer as they retain very little water once spun/rung out. 
  • Do not dry clean
  • Regular ironing may be performed at a low setting (110°C, 230°F) only, but we advise against it.

 

GENERAL WASHING TIPS
When you go to wash any garment with a zip, ensure it is done up fully otherwise the exposed teeth may cause harm in the wash cycle. The same can be said for garments containing Velcro. Your best course of action would be to wash these garments either by hand or on their own in a washing machine.

With the advancement in detergent technology, you very rarely need to wash any garments these days above 30°C. It is better to use a specific anti-bacterial wash-in treatment rather than increasing the temperature.

A lot of Sub zero products, especially the base layers and mid layers, can be ironed on a low temperature setting. We would advise against this as the heat settings on irons are not always reliable. In any case, the stretch properties of synthetics helps reduce creases in the wash and if there are any afterwards, they often drop out when worn.

Like most synthetics, Sub Zero fabrics will melt or burn if exposed to flame or direct heat. They are not flame resistant; do not use them near ANY direct source of heat or flame. This includes some of our merino wool products that contain a small percentage of synthetic yarn.

Factor 1 Base Layer Leggings are one of the best lightweight thermal underwear ranges for general outdoor use.

These thermal leggings are manufactured from stretchy tubular 100% polyamide ribbed fabric with a hydrophilic treatment for superior moisture management.

The extra generous waist heights on these leggings help to prevent lower back exposure and give extra thermal protection to your kidneys. The waist itself is constructed with an internal strong rubber elastic core that is seamed over with Factor 1 fabric for a low profile. The double layered fabric gusset provides added thermal protection around the groin, whilst the ends of the legs have flat ankle seams that help to reduce pressure exerted from walking shoes and ski boots.

These base layers cross over in to anything from, skiing, through to hiking and camping, and can be used in combination with Sub Zeros Factor 2 mid layers for extra warmth in extreme conditions.

Please note: These are end of line garments. There may be some slight colour variations where they have been folded, and some may have different versions of our logo, but apart from this these base layers are perfect. We have greatly reduced the price to reflect this. Our Factor 1 Plus legging has superseded this design. 

Scroll down the page for further product details, technical information, sizing, shipping and any washing instructions.

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