Buffalo Systems Special 6 Trousers Review

Overview

The Special 6 Trousers are the bottom half of Buffalo Systems’ famous “shirt and trousers” combo—a Sheffield-made, pile-lined, Pertex-shelled garment designed to be worn next to bare skin instead of over a base layer. They were built for the British special forces and are now a staple for mountain rescue teams, hill walkers, and anyone who spends long days out in cold, wet, blustery UK conditions. This isn’t a garment aimed at gram-counting thru-hikers; it’s for people who prioritize all-day warmth and durability over pack weight.

Key Specs

Spec	Detail
Weight	329 g
Shell fabric	Pertex Quantum
Lining	AquaTherm pile
Construction	One-piece leg design
Closures	Zipped fly, full-length open-ended side zips
Pockets	One zipped rear security pocket
Waterproofing	Water-resistant, not waterproof
Made in	Sheffield, England
Intended use	Military, police, mountain rescue, outdoor professionals

Performance

The Buffalo system works on a completely different principle than a standard waterproof-breathable shell over a base layer. The pile inner absorbs sweat and your body heat pushes it away to create a warm microclimate at the skin, while the Pertex outer is breathable and disperses that moisture to the atmosphere. In practice, that means you skip the base layer entirely and wear these directly against skin, which feels counterintuitive the first time you try it but is the whole point of the design.

Warmth is the standout quality here. One reviewer who tested the combo cycled 16 miles to work during a three-day cold snap at 0F/-18C and reported the gear kept them “warm as toast,” not just tolerably warm but comfortable enough to do all day. Another long-term user logged use in temperatures down to -3°C and wind speeds in excess of 50 mph, reporting the gear performed excellently. That’s a serious cold-weather pedigree, and it tracks with the trousers’ military and mountain rescue origins.

Wind resistance is genuinely excellent—Pertex Quantum is windproof up to 50mph per the manufacturer, and multiple long-term users corroborate this in the field. Where it falls short of a true hardshell is rain protection. As one user candidly put it, these are “warmer than my paramos, but I don’t think they are as waterproof”. That’s consistent with the fabric’s design intent: Pertex is not water-proof, but is highly water-resistant, and the level of warmth and windproofing negates any coldness, even when wet through. So you may get damp in sustained heavy rain, but you won’t get cold—which for many users in Scottish or Scandinavian winter conditions is the more important variable.

The full-length side zips are the trousers’ signature feature, letting you dump heat fast without removing boots or gaiters. One camp-use reviewer highlighted this as a practical safety feature: the design is brilliant for static warmth, easy to put on and off without putting your boots through, using the full length zips and Velcro waist, with no more tumbling over from loss of balance. That’s a specific, real use case—getting warm layers on fast at a rest stop or bivvy without losing footing on uneven ground.

Durability seems to be where the Special 6 really earns its reputation. Buffalo garments are known to last decades; one reviewer compared a 20-year-old smock against a brand-new pair of Special 6 trousers and found “not much difference” between the two even after roughly 20 years of use. That kind of longevity is unusual in outdoor gear and goes some way toward justifying the price and weight if you plan to keep a piece of kit for a long time.

The main practical complaints center on storage and fit adjustment. Pocket space is minimal—just the single zipped rear pocket—and one reviewer coming from Páramo trousers with deep hand pockets found this disappointing, with only one small back pocket, wishing for more and finding it felt very limiting. Sizing adjustment is also fairly basic: a recent buyer noted the trousers lack removable braces or a belt, which other similarly priced trousers include, and wished the velcro straps over the zippers were longer for hip adjustment. Fit is meant to be snug and close to the skin for the system to work properly, which means sizing runs differently than a typical hiking pant—check Buffalo’s sizing chart rather than going by your usual waist size.

Pros & Cons

Pros:

• Exceptional warmth-to-bulk ratio for static and low-output cold-weather use
• Genuinely windproof Pertex Quantum shell, tested to 50mph+ in the field
• Full-length side zips allow fast venting or removal without taking off boots
• Reputation for extreme long-term durability—decades of use reported
• No need for separate base layer, simplifying your layering system

Cons:

• Not waterproof—will get damp in sustained heavy rain, even if you stay warm
• Only one small zipped rear pocket; minimal storage compared to competitors like Páramo
• No included belt or braces; adjustment relies on velcro tabs some users find too short
• Snug, skin-contact fit sizing takes some getting used to and limits layering flexibility
• Heavier and bulkier than a standard shell/base-layer combo—not built for weight-conscious backpacking

Who Should Buy This

This is a specialist garment for people who spend extended time static or moving slowly in genuinely cold, wet, windy conditions—mountain rescue volunteers, winter hillwalkers, wildfowlers, high-seat deer stalkers, or anyone who needs to stay warm through long stationary periods outdoors. If you run cold when inactive and sweat heavily when active, the Buffalo system’s moisture-transport approach solves a problem that a standard shell-and-baselayer setup doesn’t handle as gracefully. It’s a poor fit for ultralight backpackers or anyone prioritizing pack weight, and if you need serious rain protection over wind/cold protection, a proper waterproof shell will serve you better.

Verdict

The Special 6 Trousers aren’t trying to be lightweight or waterproof—they’re trying to keep you warm through brutal, wet, windy conditions for decades, and by most accounts they succeed at that singular job. If your use case matches theirs—military, mountain rescue, winter hillwalking, or long static cold exposure—they’re worth the weight and the learning curve of the pile-and-Pertex system. I’d rate them 7.5/10: outstanding at their core mission, but the sparse pockets and rain limitations knock them down from cult-classic to merely very good for anyone outside their specific niche.