Why Motorcycle Helmets Use this Ancient Buckle

A couple of my early helmets in the 1970's had a "Sliding bar" fastening. They are a square ring with a sliding bar where the strap went through the ring over the bar, then returned under it.
Unfortunately the tail of the strap was fastened with Velcro, so many people by passed the bar and just used the Velcro. That is why the tail of today's helmets 'D-Ring' straps normally reverses direction after the rings.

The thing is the other clips were made of plastic tho

I'm not a motorcycle person (or a driving person for that matter) but I've been binging some of these videos

If theres 763 lbs yanking my helmets off my head, my neck is going to break first. So I definitely prefer that strap I can connect on the road with one hand without stopping. It really doesn't matter what latching system your helmet has because at that level of forced your head is coming off before your helmets.

One of my first helmets had a DD. The first time it hit 60mph the tail started flapping and within a second or two it blew off my head. Probably it's fatal flaw was round edge Ds, a slippery strap, open face and no snap to secure the tail. Retrieved, cinched uncomfortably tight it did the same thing. It was my first and last open face. Had DDs since that did fine.

If it ain't broke don't fix it. Hate the ratchet crap.

Is the assumption that the double-D ring broke at 900lb because the strap breaks at 900lb? If so, that assumption is probably incorrect, as the strap is rated in pure tension, but becomes weaker when bent (e.g. knot or buckle loop). The strap probably broke at something considerably less than 900lb.

Myth buster of Motos

Most climbing harnesses use double D buckles too. They are very reliable and fool-proof. But they tend to slip a little bit when under variable load for a long time.

man i love your videos

I'm going to have to disagree, on the part of daily commuting riders. I used to neglect to strap my d-ring helmet all the time, often simply buckling the little snap instead. When you put your helmet on and take it off at least twice a day, and average more like 6 times, the convenience of the buckle is far more important than its ability to withstand (an insane) 900lb. I'd love a fidlock option but I'm pretty happy with my ratchet buckle...and I now buckle my helmet. Every. Single. Time. Because it's quick and easy to do.

So why safety belts in cars have no double d but "garbage"? Same problem, greater forces, reliably working quick-release fastener.
I hate double d and would like to have the quick-release fastener on my first shoei helmet back. Similar to that of a car seat belt buckle.

It's really annoying, so people wont lock it - especially when you have to do it many times in short time.

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I bought a helmet with a ratchet connector. It got broken in approximatively one month of light use. That's absurd.

It's funny you have to pay a premium to get those double-D ring helmets, as if it's some advanced technology that we are paying the price for.

There's a flaw with the test method. With this type of scissor-jack, the force needed to raise a specific load varies with the angle of the scissor arms, due to how the geometry of the how the load is transmitted to the mechanism. For example, if the arms are relatively level the force needed to lift a given load is significantly more than when the arms are more vertical and near the end of their range of movement. For this reason you cannot accurately measure the load on the straps and buckle with a mere torque wrench, unless you also ensure the scissor jack arms are at the same angles at maximum load.
You could get a more accurate measurement if you ensured the length of the tested straps and buckles were the same, but I didn't see any attempt to do that during the test.

I also concur with the outcome. A double-D strap is a strong, reliable and cost-effective way to secure your helmet. I've had the plastic on other types of buckles fail after a period of time due to degradation of the plastic.

If this kind of force rips on yor helmet, your head stays in the helmet. I think its acutally saver that there is a "Sollbruchstelle".

Interesting!

I like the rachet strap. It's just so convenient.

Today I'm failed the exame because didn't tighten the helmet strap😢

ive never seen a helmet with dd rings, or know how to use them xD

... but with a ratchet you adjust it a little every time. Then every now and again ajust it back.

I'll roll the dice and use a ratchet strap cause d-rings are a pain in the ass. I figure the chance that this will one day cause me an issue in a crash is about the same as my chances of winning the power ball.

i forgot to dislike and unsubscribe

Unless the scissor jack is at the exact same geometry (scissors angles) at every specimen's Breaking Point, the torque values recorded at the screw are apples and oranges. Not useful for accurate comparison of these buckles.

i use one of the ratchet quick type ones, but only because i only have a moped at the moment. the instant i get a faster bike and start doing highway speeds im gonna go for the traditional style

Just got back on two wheels after 10 years, didn't test the strap when fitting and ended up with a ratchet clip. It's so finicky about the angle to clip it up that I'm still faster with the rings plus it makes helmet hooks pretty awkward to use.

With a double d i wear my helmet more, just not putting in the work to take it off on short stops...

I don't like to be told what to do. I've liked and subscribed.

shit, that video was so well done.

Your test may prove that Double-D is the strongest with your testing method but then that's about it. According to the fidlock website, the static breaking load of the CE certified fidlock 25 alu motorbike buckle is 1962 N which equals roughly 200 kg. I'm wondering what the breaking strength of a neck is? The 763 lb derived from the torque measured equals 346 kg, the ratchets 555 lb is 251 kg. A load cell would probably be more accurate... The certification requires the strap to hold at least 500 N for two minutes. That's a minimum of 50 kg pulling on the helmet, right.

Hahaha jokes on you... I don't own a bicycle helmet

I disliked, unsubbed, then reported for dangerous activities. Just think how many people are going to go to jail or be fired from work for going around asking for Double D's with strap-ons?

Lol I actually learned to buckle up my helmet after learning to ride it cause the teachers forgot to teach it thinking everyone knew how to

*IF IT AINT BROKE*....

Yay, I own 1 & 2 - how generic am I 😢

Id hate to be in a crash that exerts 900lbs of force on my head.

We lost a local rider due to the quick connect failing. Helmet flew off his head.

should you ever try this again, or something like it. Lay a heavy blanket over the strap. some of the energy should be taken up trying to make the blanket fly..

I’ll take the ease and 13.91 nm of the fidlock. Try navigating the DD with gloves on. Awful

Could you do this experiment with a metal ratchet buckle?

I love how your safety precautions evolved THROUGHOUT the experiment. 😂

In case you had not noticed.. Plexiglass offers a false sense of safety with no safety at all.... Lexan is what you need to be using..

unfortunately for your test the gear ratio of the jack changes as it extends so the torque numbers are meaningless unless compared to the position of the jack at the point of falure :(

still better to have a strap that you bother to lock, than one that takes so long that people don't even bother using it..

All three of these buckles could have been made of metal instead of plastic parts, then they would have fared better in the tests.

Time-tested.

I'd argue it would be better to reengineer the ratchets to get close to the DD shackle forces. Since its quick and easy its the least likely to be left just undone, you can do it up while on the bike in gloves if you forget it, and as long as you're sensible it will always be tight

polycarbonate for impact protection! Nobody makes safety glasses out of plexi ;)

Torque on wrench affects the jack differently as the jack angle changes.