GriGri

Key takeaways

GriGri belongs to science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect GriGri to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of GriGri from memory before moving on to harder problems.

Reference excerpt

A Grigri (styled as GriGri or GRIGRI) is an assisted braking belay device manufactured by Petzl designed to help secure rock-climbing, rappelling, and rope-acrobatic activities. Its main characteristic is a clutch that assists in braking under a shock load. The success of this device has led to grigri becoming a common name for devices of this type. In 2011 a new version, the Grigri 2, was released to replace the original 1991 model. Petzl released the Grigri+ in 2017, adding new safety features to the original design. However this made the device heavier and many climbers felt the new safety features (specifically the anti panic handle which stopped the device from lowering when the handle was pulled too far back) got in the way of normal operation when lowering. 2019 saw the release of an updated version of the device, simply called the Grigri. It is named for the African amulet gris-gris, believed to protect the wearer from evil.

Mechanism of operation The Grigri is a belay device. It works by generating a pinching force from the force imparted to the device's live end. When a sufficient force is applied to the live end such as in a fall, the device locks up and prevents an uncontrolled fall. This function distinguishes it from traditional belay devices such as a Sticht plate or an ATC, whose braking mechanisms depend entirely on the user controlling the rope in a specific manner to increase or decrease friction. Inside the Grigri, the rope runs along a disc cam; the cam allows the rope to pass if moving slowly enough in order to not generate a drag force over the device's threshold. Because some force needs to be present in the live end of the rope in order for the device to work as intended, it is very important for the belayer to keep a grip on the brake end at all times. This ensures there is always enough seed tension in the rope for the device to work correctly. In other words, the Grigi also has a user dependent braking mechanism.

Uses Petzl recommends the device for lead belaying and top-rope belaying, according to EN 15151 standard. When used correctly, the Grigri's camming mechanism can assist in holding a climber that is working a route, or hanging on the rope while trying to figure out a climb. When belaying, the same technique for "taking in" that is used with an ATC or similar device is used. While paying slack out into the system, if the device is held open by pressing on the cam and the climber falls, the device will lock as long as the belayer is holding the brake strand. However, the device will not lock should the belayer let go of the brake strand while holding the cam in the open position. Each generation of the GriGri has a lower limit for the rope diameter for which the cam will engage, and an upper limit for maximum rope diameter to allow for feeding. - The original Grigri is stamped MIN 10 MAX 11. - The manufacturer recommends the GriGri 2 to be used only with 8.9 to 11 mm diameter ropes. - Grigri+ and Grigri (2019) expand that lower range to be used with 8.5 to 11mm diameter ropes, with the 'sweet spot' being 8.9 to 10.5mm.

Limitations, prohibitions The Grigri has just one place for installing rope and it cannot be used in climbing with half rope. This device is not suitable for left-handed belay technique. There is a sharp edge on the side that will fray rope if used left-handed, but a smooth flange to protect the rope while belaying right-handed. However, there are special techniques that allow left-handed belayers to use this device, like reorienting it to face the other way. Some big wall climbers such as those climbing Yosemite's Half Dome or El Capitan have "invented" novel ways to extend its use and compromise its safety. For example, some rope soloists use the Grigri sometimes slightly modified as a self-feeding hands-free self-belay device. It has also seen use by the second to self-belay while jumaring the rope as one half of the ascender pair. The manufacturer holds uses outside of those validated come with considerable risks, and its official documentation goes so far as to expressly prohibit certain uses.

Parts of the GriGri and GriGri+ There are seven parts that the GriGri and the GriGri+ have in common.

Moving side plate Cam Cam axle Friction plate Handle Fixed side plate Attachment holes The GriGri+ has two additional components:

Selector knob Lock button

References

External links

Grigri (rock-climbing) Video: Belaying the leader with a Grigri Petzl GriGri Review with videos

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Illustrations

Worked examples

Example 1 — a first encounter with GriGri

Start with the simplest possible case. Write down what GriGri claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to GriGri before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about GriGri ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of GriGri

In research: GriGri appears in science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses GriGri in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: GriGri is common in secondary-school and first-year university syllabi. It links to neighbouring topics Caving equipment, Climbing equipment, Mountaineering equipment, so understanding it makes those chapters shorter.
In everyday life: Look for GriGri outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

How to study GriGri in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what GriGri means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain GriGri out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is GriGri in simple terms?

A Grigri (styled as GriGri or GRIGRI) is an assisted braking belay device manufactured by Petzl designed to help secure rock-climbing, rappelling, and rope-acrobatic activities. Its main characteristic is a clutch that assists in braking under a shock load.

Why does GriGri matter?

Because it connects several science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study GriGri?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on GriGri.