Question Non-Locking shoulder belt in sudden stop?

So, on the way home from getting dinner, I was nearly in a crash. Totally my fault, and thankfully the other vehicle was being very aware and defensive and saved us all from a collision. So, they literally, as in, within the last week, installed a brand new traffic light on a street i drive all the time. I've literally driven the road thousands of times, and simply did NOT see it...I wasn't expecting it to be there. I know, my fault entirely. I'm not making excuses. :sorry!:

Anyway, I was right up on this brand new light - which happened to be RED, when my brain processed the fact that OMG there was a RED LIGHT right there in front of me
So, I slammed on the brakes. Like, STOMPED on them, went from 35-40mph to 0-dead stop in just a second or so, in the space of a couple carlengths. I left much tire on the road
Anyyway, my concern is that dd, who was in her turbo, FLEW forward. Her belt did not lock. Isn't the seat belt supposed to lock? Mine did. Hers didn't. The booster fit remained perfect, belt stayed right on shoulder, but her entire upper body came straight forward, then she rebounded back. The belt moved with her the entire time, forward and back.
It's a switchable retractor, 2007 kia, I know it works because I've pulled it out too fast before and had it lock on me. But yet, somehow, it didn't lock up today? What's up? Shouldn't a sudden stop like that cause it to lock up?

NAK*



If yours locked I would assume hers would as well. That is concerning. I would consider locking her in if the retractor is switchable. If it isn't, can you mover her and have i checked? I don't know how that would work, but I'm sure it can be done.

Glad no one was hurt. We all make mistakes. They put up a new stop sign right in front of the park in our neighborhood. They turned a 1way stop into a 3 way intersection. I never speed through there (there are also massive speed bumps big enough they can eat the bumper on large suvs and trucks). I have run the stop more than once, but probably as much as 3 times. I'm going 15mph, but it happens. I know plenty of people fly through though, that is how I know of the damage the speed bumps can do, I've seen them.

I've had it happen to me in my Honda, which has very touchy retractors. It will only lock if the webbing is playing out fast enough. You've found this in your vehicle when you yank the belt a bit too fast. Anyway, when it doesn't lock on me in my vehicle, it's usually because I'm using some of my torso muscles to resist the forward motion. That slows down how quickly the belt plays out and therefore doesn't quite get the belt to lock.

On a different day, a less-sudden stop that I don't try to resist, the belt will lock. I have no doubt that my belts will lock properly when I really need them to.

Pixels said:

I've had it happen to me in my Honda, which has very touchy retractors. It will only lock if the webbing is playing out fast enough. You've found this in your vehicle when you yank the belt a bit too fast. Anyway, when it doesn't lock on me in my vehicle, it's usually because I'm using some of my torso muscles to resist the forward motion. That slows down how quickly the belt plays out and therefore doesn't quite get the belt to lock.

On a different day, a less-sudden stop that I don't try to resist, the belt will lock. I have no doubt that my belts will lock properly when I really need them to.

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That crossed my mind, but I couldn't process it into words.

Sometimes the belt can get hung up in the belt guides and have slack behind it. If that's the case, it may not have pulled out fast enough to lock.

:yeahthat:

I had to rearrange my boosters into different cars becasue the JANE ( headrest in the lower positions) in my Civic causes slack behind the booster headwings. It's like the seatbelt is pinched between the booster belt guide and the car's built in headrest.

I'd check that on yours.

If it's not that, I'm left scratching my head.

I DO know that of I stop too suddenly my girl's belts lock. we aren't going fast, but if I just break hard, I'll hear "mommy, you made my seatblet lock!" from the backseat.
Her belt definitely should have locked during your breaking.

theres definitely no slack in the belt. hmmm...she probably was "resisting", as pixels said.
I guess i still have to assume/hope tghat it will work when truly needed.

I remember reading somewhere about this being pretty common, and a reason that it's not so bad to lock seatbelts on booster riders :/.
Here's a fascinating, if not totally related study on rear seat safety... http://www.sae.org/events/gim/presentations/2008hong.pdf In short, I gather that rear seatbelts aren't really up to the tough standards that front belts are, and that adults are way safer in the front seat, but that's just a random factoid.

joolsplus3 said:

I remember reading somewhere about this being pretty common, and a reason that it's not so bad to lock seatbelts on booster riders :/.
Here's a fascinating, if not totally related study on rear seat safety... http://www.sae.org/events/gim/presentations/2008hong.pdf In short, I gather that rear seatbelts aren't really up to the tough standards that front belts are, and that adults are way safer in the front seat, but that's just a random factoid.

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Some cars prohibit locking the belt on booster riders.

DahliaRW said:

Some cars prohibit locking the belt on booster riders.

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Do share more, please?

DahliaRW said:

Some cars prohibit locking the belt on booster riders.

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And I would sort of question if their intent is not that the locked belt is dangerous, but that they are trying to clarify the difference between an installed, harnessed seat which MUST be locked, and a booster which doesn't have to be. I've never gotten a really clear answer on that, and I suspect SafetybeltSafe would warn against it more strongly (rather than recommend it if needed for a new/wiggly/sleeping booster rider) if there were any known danger, kwim?

joolsplus3 said:

And I would sort of question if their intent is not that the locked belt is dangerous, but that they are trying to clarify the difference between an installed, harnessed seat which MUST be locked, and a booster which doesn't have to be. I've never gotten a really clear answer on that, and I suspect SafetybeltSafe would warn against it more strongly (rather than recommend it if needed for a new/wiggly/sleeping booster rider) if there were any known danger, kwim?

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The manual for my Sienna specifically says:

When installing a booster seat
-Do not fully extend the shoulder belt to prevent the belt from goign to ALR lock mode
-ALR mode causes the belt to tighten only which could cause injury or discomfort to the child

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The next paragraph starts "when installing a child restraint system"

So no, not decifering, it's saying it could injur the child!

Meh, ok, I'll believe it, sort of, except I still think it's more them covering their butts in case kids get entangled/strangled in them or something, not because it fails crash testing dramatically.

The thing is we don't know. And we don't know how the seatbelt reacts on a BODY when in ALR mode in a crash. It may be designed to have a little give like it would in ELR mode. It's different when used to install a car seat, since it would be the shell of the seat that would impact the belt and not a body. But, if my car manual says don't do it, I'm not doing it. To me it's not a big deal. I know my ds's belt has locked when we've stopped suddenly, so it works.