DOUBLE-RING VS. MICROMETRIC: WHICH CLOSURE IS RIGHT FOR YOUR HELMET?
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Helmet safety doesn't end with the shell. The closure system can make the difference between a helmet that stays on your head during an accident and one that comes off.
When choosing a helmet, you probably focus on materials, certifications, and comfort. But there's a detail that many underestimate: the strap closure system . Double D-ring or micrometric? It's not just a matter of convenience—it's a choice that affects safety, ease of use, and areas of application.
In this article, we explain everything you need to know to make an informed choice.
DOUBLE D-RING: THE GOLD STANDARD OF SAFETY
How does it work?
The double D-ring system is the oldest and most proven method of fastening for motorcycle helmets. It consists of:
- Two D-shaped metal rings permanently attached to the left strap of the helmet.
- A strong nylon strap that passes through both rings and folds back on itself.
How to fasten:
- Thread the strap through both D-rings.
- Bring it back by passing it through only the first ring.
- Pull firmly to tighten.
- Fold the excess end to prevent it from flapping.
Strengths
✅ Maximum Security – Considered the most secure system available. It has no mechanisms that can break or fail.
✅ Mandatory in competitions – All racing federations (FIM, Snell, professional competitions) require ONLY the double D-ring. It is the only system approved for track use.
✅ Perfect adjustment every time – You have to adjust it manually each time you wear it, which always ensures the correct tension.
✅ Extreme durability – Nylon and metal: no plastic parts that can break with wear or impact.
✅ Unlimited Durability – Does not wear out or deteriorate. Works perfectly for the entire life of the helmet.
✅ Reliable in all conditions – Works even with thick gloves, wet hands, and in extreme cold.
Areas of use
The double D-ring is mandatory for:
- Racing and competitions (MotoGP, Superbike, track)
- High-performance sport riding
- Track days
It is preferred by:
- Professional and semi-professional pilots
- Sporty riders who seek maximum safety.
- Motorcyclists who travel long distances and want total reliability.
- Those who prefer safety over convenience.
MICROMETRIC CLOSURE (MICROMETRIC/RATCHET BUCKLE): CONVENIENCE AND SPEED
How does it work?
The micrometric closure is a ratchet system with a buckle made of reinforced plastic or metal. It consists of:
- A ratchet buckle attached to one side of the helmet.
- A toothed belt that attaches to the buckle.
- A quick-release button to open
How to fasten:
- Insert the toothed belt into the buckle.
- Pull until the desired tension is reached (the ratchet locks automatically).
- To open, press the release button.
Strengths
✅ Extreme Speed – Fastens and unfastens in 1-2 seconds. Perfect for those who frequently get on and off the motorcycle.
✅ Ease of use – No practice required. Even with thick gloves, it's immediate.
✅ Pre-set adjustment – Once the length is adjusted, it always maintains the same tension.
✅ Comfort for urban use – Ideal for those who make short trips in the city and stop frequently.
✅ No flapping ends – The strap always stays in place, without tails flapping in the wind.
Areas of use
The micrometric closure is ideal for:
- Urban use and commuting (city, traffic, short trips)
- Scooters and city motorcycles
- Riders who stop frequently (deliveries, work, shopping)
- Relaxed tourism
It is prohibited for:
- Competitions and track use (not permitted by Snell, FIM and other racing federations)
- Track days (depending on the circuit's rules, but often not allowed)
TECHNICAL COMPARISON: DOUBLE D VS MICROMETRIC
SAFETY
- Double D-Ring: Maximum – no mechanism that can fail.
- Micrometer: Good – but it depends on the integrity of the buckle.
SPEED OF USE
- Double D-Ring: Slow (10-15 seconds)
- Micrometric: Very fast (1-2 seconds)
EASE OF USE
- Double D-Ring: Requires initial practice
- Micrometrics: Immediate
REGULATION
- Double D-Ring: Manual each time
- Micrometrics: Pre-set
DURATION
- Double D-Ring: Unlimited
- Micrometrica: The buckle may wear out or break.
RACING APPROVAL
- Double D-Ring: ✅ Required
- Micrometrics: ❌ Prohibited
USE WITH GLOVES
- Double D-Ring: Possible but less practical
- Micrometrics: Very practical
RELIABILITY
- Double D-Ring: Total
- Micrometric adjustment: It depends on the quality of the buckle.
HELMET PRICE
- Double D-Ring: Generally premium helmets
- Micrometrica: All price levels
WHY IS THE DOUBLE A-RING MANDATORY IN COMPETITIONS?
Racing federations such as Snell, FIM, and FIA require exclusively the double D-ring for a simple reason: it is the only system that guarantees absolute safety in the event of an extreme impact .
During a high-speed accident:
- The helmet is subjected to enormous forces of traction and rotation.
- A plastic buckle could fail or come undone.
- The double D-ring, being only nylon and metal, cannot break.
Certified data: In Snell tests, the double D-ring system has been shown to withstand tensile forces exceeding 1,000 Newtons without failure.
WHICH ONE TO CHOOSE? IT DEPENDS ON YOUR DRIVING STYLE
Choose the DOUBLE AD RING if:
- Do sport riding, track days or competitions.
- You are looking for maximum security without compromise.
- Do you travel long distances and want total reliability?
- Do you prefer a simple, robust system without mechanisms?
Choose MICROMETRICA if:
- Do you mainly use the motorcycle in the city?
- Get on and off the vehicle frequently.
- Do you want practicality and ease of use?
- You don't do track driving or high-performance sports driving.
MY PREFERENCE: DOUBLE AD RING
Personally, I prefer the double D-ring. Yes, it takes a few seconds longer to fasten, but safety is priceless . Knowing that my helmet will stay securely on my head in any situation gives me a peace of mind that no convenience can replace.
Plus, after a little practice, fastening the double D-ring becomes automatic—and that manual action reminds you every time to make sure it's tight.
PRACTICAL TIPS
If you use the double D-ring:
- Practice tying the knot until it becomes automatic.
- Always check that the strap is well tightened (it should be snug but not constricting).
- Fold the excess end to prevent it from flapping.
If you use micrometry:
- Regularly check the condition of the buckle (cracks, wear).
- Adjust the length each time you change your clothing (thick jacket vs. t-shirt).
- Replace the helmet if the buckle is damaged.
CONCLUSION: SAFETY FIRST
Whether you choose a double D-ring or a micrometric buckle, the important thing is that the strap is always fastened correctly . A helmet that is not fastened or is fastened incorrectly can come off during an accident—and at that point, it doesn't matter how expensive or certified it is.
The double D-ring is the gold standard of safety, mandatory on the track and preferred by professionals. The micrometric buckle is practical and fast, perfect for urban use.
The choice is yours. But safety is non-negotiable.
Because the road is freedom, but freedom requires responsibility.
Selected Style, Inspired by the Road 🏍️
Come and try our helmets with both closure systems at House of Riders.