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Jam Session

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Sink your mitts with these helpful hints


Jamming isn’t something you learned by climbing trees as a child. Instead of grabbing normal holds, you wedge body parts into cracks. It’ll take some practice, but once you learn the techniques, cracks become your roads to success on all kinds of rock. And when the crack is hand-sized, it can be a highway to heaven.

Hand jams in constrictions

On easier, more featured hand cracks, the rock will do the wedging for you. Imagine your hand as a big piece of passive pro, like a nut. Insert it into a wide part of the crack, karate-chop style, thumbs-up. Then, tuck your thumb into your palm and let your hand wedge at the narrower bottom of the slot. Pull on it and repeat.

Parallel-sided hand jams


Hand-sized slots with narrower constrictions make for easy jamming, but many cracks are parallel-sided, requiring you to actively press your hand against the walls of the crack, with friction holding the jam in place. To do this, insert your hand into the crack, and then tuck your thumb and firmly flex your fingers so that the heel of your hand, your fingertips, and the back of your hand and/or knuckles form a “magic triangle” of pressure points inside the crack.

Simple, but not easy, at least at first. With enough practice, however, you should be able to hang from jams like this as easily as from a pull-up bar.

Warning: hand jamming hurts a bit, especially when you are new to the techniques or the rock is very coarse. Do yourself a favor and apply a light tape job before setting out to learn.

Thumbs-down hand jams


In addition to the classic karate-chop style, you can also do hand jams thumbs-down, which you’ll find especially useful if a crack slants. Thumbs-down jams are useful in vertical cracks, too, since they apply a twisting force that can help your hand stay wedged in less-than-ideal jams. Look for sweet spots in the crack: wider or narrower sections that feel good on your hand, ideally tapering down below the jam to help you wedge. Try different hand orientations; a good jam should feel secure and comfortable. Many additional techniques are possible. For example, try to “undercling” from a low, thumbs-up jam to make a long reach past a bulge or off-sized section of crack.

Foot jams


Good in-the-crack footwork separates the true crack climbers from the thrashers. Handsized cracks usually fit feet well. To jam a foot, begin in the “crack-climbing Lotus position” by raising your foot to shin level and dropping your knee to the outside; the sole of your shoe should be parallel to the crack. Insert the toe of your climbing shoe sideways into the crack. Once the toe is in, cam it firmly into place by bringing your knee back into plumb.

Warning: It’s easy to get a foot stuck in a hand crack. Leave a little bend in your knee when you stand up so you can drop the knee to remove the jammed foot. Don’t over-wedge, especially in wider hand cracks. Place feet as you’d place pro: solid enough to do the job, but easy to extract when it’s time to move on.

Wide and thin cracks

With a little grit, you will soon master your “perfect” hand crack size—mine is about 2.5 inches—but it will vary with the size of your mitts. Add or subtract one half inch from your optimum size, however, and you will begin to face new challenges:

“Thin-hands” cracks don’t allow you to slide your thumb into your palm, so your ability to apply a wedging force is greatly compromised. The keys to thin-hands jamming are: 1) twisting techniques such as thumbs-down jams; 2) meticulous footwork, using pointytoed shoes; and 3) letting go of the idea that the jam should feel secure.

Wider hand cracks—a size sometimes called “cups”—force your hand into a fully flexed position where your fingers are completely cupped around your thumb. Two of the three points in the “magic triangle” are the same: the fingertips and heel of the hand. On the other side of the crack, however, only the back of your knuckles, instead of the whole back of your hand, touch the rock. Because of this one sharp point of contact, wide-hands cracks are painful. Tape over the knuckles is highly recommended.

The keys to successful cups jamming are: 1) tape; 2) taking full advantage of the perfect foot jams that usually come with the package; and 3) creative use of forearm jams and deep hand wedges to ease the pain and pass tricky wide spots.

Finishing tips: in all hand jamming, keep these points in mind:

  • Don’t just pull down on jams; pull out. Leaning back on your jams will allow you to press your feet into the wall, helping you use tiny footholds or smear on holdless sections of wall. When good face holds appear, however, use them. Combining crack, face, and stemming moves will distribute the strain across different muscle groups, plus give your ankles and feet a much-needed respite from twisting into the crack.

  • To move up the crack, you can jam hand-over-hand or “shuffle”: one hand high, leading the way, and the other low, with the bicep in its power position. There’s often no “right” way to climb a crack, so try mixing it up with different techniques, shift muscle groups, and see what works best.

  • Learn to place good pro fast. When you stall in one position, hand and foot jams start to feel slippery. Get the small gear out of the way, carry plenty of hand-sized pieces—up front or on your harness—and plug them in at chest or waist level for fast and easy rope-clips.

  • If you start slipping, improve your foot position. Raise or lower one or both feet, locate a helpful face hold, or remove and reset your foot jams more aggressively. When your feet are solid, even marginal hand jams feel a lot more secure.

  • Don’t think too far ahead. Hand cracks can be steep and intimidating. Take them one jam at a time, but keep moving. Pace yourself and don’t get psyched out by how long the climb is, or how far until your next piece.