You don’t have to climb outdoors for very long to find out what “rope drag” is. Rope drag is the friction caused as the rope passes through the quickdraws. This is made worse by placing lots of gear or by placing several pieces of gear that aren’t in line. With a single rope, if protection is placed in a zig-zag fashion, out of line of the climb, the friction increases dramatically.This can make upwards progress harder, as there is a force pulling downwards on the climber. Many climbers get around this by using “half ropes” – two ropes used together, clipped alternatively (clipping protection on the left side with the left rope and vice versa), however there are ways to minimise rope drag using single ropes. The easiest way to do this is to extend gear placements.
Extending a gear placement does two things. Firstly, it brings the placement back in line with the route of the climb, decreasing rope drag. Secondly, extending gear makes it less likely to pop out when the rope pulls on it as the climber continues upwards. The longest common quickdraws are 25cm in length and the next size of sling that most people carry are 120cm, which can be too long (and what if you need it later on?)
Enter the trad-draw:
2 x Snapgate karabiners
1 x 60cm sling
2. Loop the other end of the sling through the snapgate:
1) Unclip all but one of the loops on the bottom snapgate:
Trad-draws are an easy way to carry longer slings for recessed placements and reducing rope drag on single ropes. Adding a couple to your rack gives you more options when placing gear. You can make a trad-draw by starting off with both snapgates attached to the sling and passing one through the other, but I left one off for clarity.
I certainly do not suggest using rubber bands or similar to hold the karabiner in place. The sling can twist around, so that all the weight is placed on the rubber band, not the sling, with potentially fatal results. See this video for more.