Buyers' Guide - Shell Pants

The first choice you need to make is between straight pants and salopettes or bibs with shoulder straps to keep things secure. For most walking use, normal high-waisted trousers should be fine. They're generally lighter and smaller packing, not to mention cheaper than their higher cut brethren.

With harnesses, when climbing though, they tend to slip inexorably downwards as your upper layers levitate. The result is a cold spot in the small of your back. Salopettes or, as the American brands call them, 'bibs' are a solution.

Elasticated shoulder straps keep the waist hoiked up and secure. The downsides are that they're heavier, more expensive, more difficult to take on and off without removing a shell jacket as well and, by creating a double layer of fabric in some areas, tend to reduce breathability. When all hell's breaking loose in a Cairngorm blizzard however, they have a nice, bombproof feel.

A halfway house is a pair of high-waisted pants with braces which share some of the plus points of both designs and are a good halfway house. More protective in the waist area than plain pants and less prone to pulling down, but lighter and simpler than full-on bibs.So here are some pointers to help you choose the ideal waterproof legwear this winter...

The good news is that legs seem less sensitive to breathability than the upper body, so you don't have to agonise quite so hard over material choice. Breathable, waterproof fabrics like Gore-Tex and eVENT will both do a decent job as will many 'own brand' breathables.

As with jackets, Paramo's waterproof legwear tends to be too warm for some, but ideal for the colder-blooded user.

In general, as wtih jackets, the lighter and thinner the fabric, the less durable it will tend to be, so if you're in the habit of thrutching up rocky chimnies then you're probably best off avoiding the really lightweight kit.So here are some pointers to help you choose the ideal waterproof legwear this winter...

Overtight or badly cut overtrousers will restrict your leg movements, a particular nightmare for climbers, but not great for anyone. Fortunately increasingly cunning design means that well-designer variants can off er a good compromise between a snug, non-flappy fit and good freedom of movement.

Look for articulated knees - made to allow acute bending for those high step-ups - and stretch panels in the seat and knees, again to help you move. With high-cut pants, look for a raised section at the small of the back for enhanced protection.

Try before buying and simulate some big steps. Make sure that you have enough length in the legs and that they don't get tight across the knee at full stretch. Try bridging across too, as if climbing. If they restrict your movement, don't buy 'em.

In an ideal world you want to be able to don or remove shell trousers without removing your boots. This is even more important if you need to use crampons or skis, since often it simply won't be possible at all unless you have full-length side-zips.

These are double-ended zips running the full length of the legs. Putting such trousers on is still a faff, but removing them is easy. Next best solution is a pair of pants with a very long side-zip that will allow you to pull them on over your boots. Shorter zips can be problematic unless you're prepared to remove footwear.

If in doubt, we reckon full-length is the way to go. Don't count on putting the trousers on over, say, crampons, being hassle free, but it is, at least possible.

A secondary point is to beware of bulky side-zip systems with double Velcro-fastened flaps which cause bulk and increase complexity. A water-resistant zip with a storm flap should be enough. You can also use full zips as side vents in some cases - great on a hot glacial trudge.

If you're a winter mountaineer or ice climber, reinforcement on the inside of the ankle - some sort of Cordura Nylon patch is the most common version - will reduce the chances of you cramponing your trousers to death in a moment of careless abandon. They're not infallible though and your best hope of preserving the material is simply careful crampon technique.

If you habitually wear gaiters over your trousers then you don't need to worry about these. For non-crampon use, the patches will also reduce abrasion damage from boots. Other commonly reinforced areas include the seat - great for sitting on abrasive things, like, erm, armchairs - and the knees. A great idea if you are terminally clumsy or have awful climbing technique...

At the waist, look for a fastening that's secure, but won't get pressed into you uncomfortably by a harness or pack belt. Big plastic buckles aren't great for this reason. Some elastic in the waist band will help with fit and reduce falling trouser syndrome, particularly on models without braces.

At the ankle, we look for an adjustable cuff that can be worn either inside gaiters - for snowy conditions - or outside when it's raining hard. The difficulty is that anything with that sort of versatility can get bulky, so check carefully for both slimmish lines and for a secure fasterning system. Most use Velcro for quick and easy adjustment.

If that all sounds a bit complicated, you can always buy a cheap pair of lightweights, accept that you won't wear them much and throw them away once you've trashed them. Legs tend to cop more wear than upper bodies and it may simply not be worthwhile investing lots of dosh in a pair of shell trousers...

More Help and Advice

This article should have given you some basic pointers. The good news is that there's a load more advice on OUTDOORSmagic:

• Ask on the gear forum about general issues or specific items.
  
• Check the member reviews section for user experiences of kit.
  
• See OM editorial reviews on the front of the site for our impressions.
  
• Ask Richard Gear if you have a specific question you need answering.