What is a Double-D ring helmet fastener?

D-ring or Double-D ring fasteners are one of the main – and best – types of helmet fasteners you’ll find on modern motorcycle helmets.

They’re pretty low-tech but by using solid components that won’t break and masses of friction between them, they make for great helmet fasteners.

They consist of two metal D-rings on one side of the fastener and a simple strap on the other. Pass the strap through both D-rings, then round and through the centre of the first D ring and pull it tight to fasten. This forms a tight slip-knot around the D rings which is infinitely adjustable and very resistant to pulling: pull the helmet away from the head and the strap tightens against the D rings.

If you’ve not come across a D-ring fastener before, here’s a step-by-step guide of how to fasten them.

Double-D rings are a simple but effective way to secure a helmet and because they use few movable parts, they’re cheap to make and reliable in use.

They’re also easy to open too. Older D rings are opened by pushing the D rings away from the neck which loosens the mechanism and allows the strap to slide free.

Most modern Double-D rings also come with an attached red removal tab. Pull down on the strap and it’ll release the D ring.

Many also come with either a stud or magnetic strap end to secure the loose end of the strap and stop it flapping about.

Pros of D Ring fasteners

Strong & reliable components

Infinitely and easily adjustable

Encourage correct tightening with every use

Cons of D Ring fasteners

Fiddly to tie in the first place

Fiddly to loosen (until you’ve got the hang of it)

Need user to ensure correct adjustment – with every trip

Not as easy to use as a micrometric fastener

Double-D rings and Micrometric fasteners (sometimes called ratchet fasteners) are the most popular fasteners on crash helmets today. Whichever you opt for, they’ve both passed either ECE (European) or DOT (US) testing and offer good levels of safety. So, it’s really down to personal preference.

However, if you’re new to buying a crash helmet, we’d suggest that a micrometric fastener is probably easier to get the hang of. But make sure you read our micrometric fastener page to check out all pros and cons.

For all our motorcycle helmet reviews and previews featuring helmets with double-D ring fasteners, visit our D-Ring fastener page.