There’s an article in the October issue of US magazine  "Climbing" featuring our sponsored climber Tom Randall and his crack machine.

Check out the article below or go to to find out how to get hold of the magazine.

Homemade Crack

Build your own jamming machine

By Tom Randall and Amanda Fox

Britons Tom Randall and Pete Whittaker became well-known in the U.S. last fall for making the first free ascent of what’s considered the hardest offwidth in the world. Century Crack, a 5.14b in Utah’s Canyonlands National Park, required two years of training on “crack machines” in Randall’s cellar, including a six- and nine inch roof crack; a 40-foot, two-inch horizontal crack; a 45-degree-overhanging armbar crack; and a kneebar sit-up machine. Unless you live near Indian Creek or Yosemite Valley, or your local gym has graciously included cracks in its wall plan, specific training for crack climbing can be hard to come by. Here, Randall shares his pointers for how to build and make the most of a crack machine for at-home training.

Note: Step-by-step instructions are beyond the scope of this article, but moderately skilled DIY types should be able to bolt together planks to make a crack machine and assemble a simple frame to support it.

What’s a crack machine?

Generally made of wood, a crack machine can vary in width and length, but is usually no more than six to eight feet long, depending on available space (see below). “You can climb continuously up and down to create the feeling of being on a long crack route,”

Randall says. “The training benefits are immense, as the muscle groups are worked in a specific way, and the potential for endurance laps is infinite.”


How much room do you have? If you’re planning to build in a garage or sizeable room, consider a freestanding apparatus that can be moved around as needed. This also won’t affect the structure of your home. If you’re confined by space, however, attaching the device to the ceiling (if appropriately built) is the best way to go. Look for exposed beams or floor joists in a garage, cellar, or attic.

Wood type

Consider three things when picking out lumber for the crack machine:

1) Don’t buy skinny, flexible wood or your machine will expand when weighted. Randall recommends 2 x 6 planks.

2) The cheapest wood isn’t always the straightest wood. The straighter the planks, the better and easier the construction will be.

3) Pick out lumber that’s smooth (but not too slippery) to avoid splinters. Pine is relatively inexpensive and lightweight. You can paint a nonskid coating onto the wood, but tape up or risk tearing up your hands.


Consider your ultimate goal when creating the machine. A 30-degree-overhanging crack can make you stronger, but it won’t help as much as a horizontal crack if your project is true roof.

“The specificity in this sport is extremely important,” says Randall, “and can dictate your performance massively.”


Build the crack long enough to force you to make at least four to six moves in a row. (Try for an even number of moves to balance both sides of the body.) Randall recommends climbing the moves in reverse in order when you do laps, and repeating until you’re exhausted.


If you know you’ll be spending a lot of time on hand cracks, or finger cracks, or offwidths, build to that specific size, Randall says. It’s easier and quicker to build a consistently sized machine than to try to configure different widths on the same beams and/or build an adjustable machine. If you’re gunning for different-sized cracks, use three or more boards bolted together to create two or more cracks.

Training Ideas

Do “endless” laps on the machine—try to climb in blocks of 20 feet, 50 feet, or even 100 feet. Hold static positions on the machine for 30 seconds, rest, and repeat. Practice your foot jams—hanging from your feet helps with offwidth practice and gives a great core workout.