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The Biggest Mistake With The Easiest Fix

by Pete Whittaker
Dec 30, 2025
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I was teaching a class at The Castle in London recently, and it reminded me of the single biggest mistake I see almost everyone make when they start crack climbing.

It’s an easy mistake and easy to fix, so don’t worry.

 

The Fundamental Mistake

Right, that mistake…

You know the concept of making the jamming body part as thin as possible before inserting it into the crack (and if you didn't know that, you do now!).

However, so many people start making the finished jam before the body part is fully inside, leaving part of their hand, arm, leg, etc, outside the crack.

Why do we do this?

Because we want security immediately. We feel the body part enter the crack and our instinct is to twist, tense, and expand. But when you start to "make" the jam, this stops you from pushing it in any further, which leaves you with a shallow and weak jam.

 

The Fix: Depth Over Initial Security

The golden rule is that you must prioritize depth over initial security. You need to get the body part fully inside before initiating any of the next steps. This means ensuring the jamming part is fully contained within the crack—the jamming part should be beyond the crack's edge, so for a hand jam the whole of your thumb pulp must be inside.

 

Here are the steps to a better jam:

Prioritize Profile: Keep the body part doing the jamming action in its thinnest possible profile.

Insert and Push: Insert the body part into the crack (give it a deliberate push and wiggle if it's tight).

Is it deep enough?: Only when you are 100% convinced the body part is fully inside should you proceed.

Finish the Jam: Now you can twist, tense, expand, etc.

 

It all sounds so simple, and it is… But next time you place a hand jam, look at your hand and ask yourself “have I really kept it in its thinnest profile until it’s fully inserted”.

This simple shift in priority depth first is one of the fastest ways to improve the quality of every jam you place.

 

 

Want to learn more about crack climbing technique? join Global Crack School

 Join here

 
 

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