Step 1: Select a Diameter
In general, a thicker diameter means a stronger, more durable rope. It's also heavier.

* Typical single ropes measure 11, 10.5 or 10mm. These ropes are appropriate for rock, ice and glacier travel

* Lightweight, 9mm single ropes are used for simple glacier travel but are too thin for holding falls on vertical rock

* 8.8mm ropes are used in pairs, clipped to separate protection pieces to reduce rope drag on circuitous routes. These ropes should not be used singly

Step 2: Select a Length
Depending on the types of routes you typically climb, choose a rope length.

* Longer ropes allow longer pitches and rappels

* Shorter ropes weigh less and take up less space

Step 3: Select a Strength Rating
Look for ratings of static elongation and maximum impact force:

Static elongation measures the amount a rope stretches when weighted with a standard load (80 kilograms/176 pounds).

* Ropes with low static elongation stretch less (useful in aid climbing)

* Higher static elongation means ropes have more stretch (cushioning the impact of a fall)

Maximum impact force refers to the amount of force transmitted to a climber during a fall.

* Low maximum impact force means the rope (not the climber or the protection) absorbs more of the energy generated in a fall. However, such ropes stretch more, increasing your chances of hitting the ground or a ledge

Step 4: Choose Dry or Non-Dry
Soggy ropes are heavier and less able to absorb falls. In cold conditions, absorbed water can freeze and make a rope weak and unmanageable.

* Dry-treated ropes last longer than non-dry ropes and are easier to handle when wet. However, they are not completely waterproof, and treatments do wear off over time. (Wash-in products are available for re-waterproofing your rope)

* Non-dry ropes are less expensive and ideal for use in dry conditions

When to Consider a New Rope
Ropes aren't cheap, but neither is your life. Follow these basic retirement guidelines even if your rope shows no visible signs of wear:

* Occasional Use (every other weekend or so)—Replace after four years

* Weekend Climbing—Replace after two years

* Sport Climbing—Repeated, short falls can be very hard on a rope. Replace about every six months. Many climbing gyms replace ropes every few weeks

* Hard Falls— Replace your rope after ANY hard fall. Also replace it if it has flat or soft spots, becomes stiff or shows sheath damage

* In Doubt?—If you're not sure, replace it!