Headgear is required when climbing rock and ice, per the coach's instructions.
The risk of rocks falling is always present, and it is unpredictable. Everything can fall on your head at any given point in time. Most accidents involve objects falling from above. On the other hand, climbing risks falling or swinging and sustaining a head injury. You also run the chance of hitting your head on the ground.
Can bicycle helmets be used for climbing?
First and foremost,
rock climbing helmets are designed to prevent falling rocks and cushion impact.
Sweat and ventilation are prioritized in the design of cycling helmets. However, the gap above is too large to fill with little gravel and large stone.

Secondly, because the bicycle requires a lot of spine bending, the cervical spine must bend backward. The back of a bicycle helmet should be less covered than the back of a rock climbing helmet. Otherwise, the extra component will cause you to bend your neck.
Bicycle helmets must also take wind resistance into account. The primary purpose of bicycle helmets is to reduce wind resistance. Rock climbing helmets, which cannot block pebbles, have far fewer ventilation openings.
Bicycle helmets are not recommended for rock climbing due to the differences in characteristics between rock climbing and riding.
Why do you need to wear a special climbing helmet for climbing?

Helmets work on the same idea of protection. To protect the head, they all use the rupture of helmets to absorb the impact force during a collision. On the other hand, rock climbing helmets are designed and tested differently than other helmets.
All climbing helmets made in Europe and America must meet European Union (CE) or UIAA standards. All helmets marketed in Europe must pass the CE standard test, which the European Union mandates. Even though the government does not have similar required rules, all climbing helmets marketed in the United States should pass the CE or UIAA standard inspection due to market competition and legal issues.
Union Internationaledes Associationsd'Alpinisme (UIAA) is the governing body of international mountaineering. The European Union (CE) standard on climbing helmets is En12492, and the matching UIAA standard (UIAAStandard106) is based on the CE standard, but it is more strict than the CE standard, which is briefly introduced as follows:
1. Positive impact test
A 5kg blunt head weight (blunt head radius 5cm) falls freely from a height of 2 meters to strike the top of the helmet, and the impact force on the dummy's neck (wood) must be less than 8 kN (UIAA standard); must be less than 10 kn (CE standard). A thousand Newtons (9.8 Newton = 1 KGF) is around 100 kilograms of force. To put it another way, the impact force on the dummy's neck must be less than 800 kg (UIAA standard) and less than 1000 kg (UIAA standard) (CE standard).
2. Side impact test
: Test from the front, two sides, and back at a 60-degree angle with the positive direction (top of the head). The blunt head weight must fall freely from a height of 50cm, and the impact force on the dummy's neck must be less than 8kN (UIAA standard); it must be less than 10kN (UIAA standard) (CE standard). The sensor detects the impact force borne by the neck in positive and side-impact tests. It demonstrates that, like the power rope, the helmet is essential not only to prevent impact but also to absorb kinetic energy and slow down impact. The impact on the wearer's cervical spine and spine is reduced via helmet shock absorption.
3. Penetration test with a sharp object
: A 3-kilogram cone with a 0.5 mm tip is dropped freely from a height of 2 meters, and the helmet must withstand at least one impact. Damage to the helmet is permitted; however, sharp items must not come into close contact with the scalp.
4. Stability test (also known as fore-and-aft displacement test)
: A 10 kg weight is thrown at the helmet from the front and back, and the helmet must still fit the dummy's head properly (record the moving angle of the helmet after being hit during the test). Please pay close attention to the test standard's clauses 1 and 2. The sensor here detects the impact on the neck. It demonstrates that, like the power rope, the helmet is essential not only to prevent impact but also to absorb kinetic energy and slow down impact. In addition, the helmet's shock absorption feature is intended to reduce the impact on the wearer's cervical spine and spine.
A decent climbing helmet can take more punishment. Durability is crucial for long mountain hikes or large-scale wall activities.
As a result, it's best to use a climbing helmet.