Diono Radian RF seatbelt install

Mom_In_SA · Dec 2, 2013

Hi all, I just watched a youtube video which showed the installation of a Radian RF with a seatbelt. I must admit, it doesn't seem all that secure to me

I am used to a seatbelt install where the shoulder portion is routed around the back of an RF seat.. and I am wondering whether the US version causes the seat to move a lot more during turbulence (not necessarily a crash, even sudden hard braking or sharp corners)?

Is this the reason that US seats have top tethers? Even so, Diono states that tethering is not mandatory for their seats :scratcheshead:

tiggercat · Dec 2, 2013

Which video did you watch?

A correctly installed rearfacing radian may have a bit of movement at the top of the seat shell, but will be tight at the belt path. Generally, the seat will not move during regular driving including braking or turning. The seat performs well in crash testing, and meet or exceeds fmvss/cmvss standards, as do all seats on the market.

Rearfacing tethering is optional, and may increase the stability of the restraint.

MammaBear · Dec 2, 2013

We have a 2008 Kia Sedona minivan and for the life of me I COULD NOT get the seat secure RFing in the back row. The belt would be completely tight, but something was up that made it possible to completely turn the seat on its side. I spoke to someone else on here who had the same problem in a different van. NO idea what was going on. My RFing Dionos stay in the captain's chairs. I never had a problem with my MRs rfing in the back....

And maybe I wasn't supposed to pull the seat like I was - my concern was that in a side impact collision the seat would flip right over. I just gave up.

Mom_In_SA · Dec 3, 2013

The video I watched was done by a tech from Diono. I don't think this type of installation is specific to this specific seat, I think all seats from the US have belt paths that are similar?

The seat belt routing that I am familiar with is the european seats (I have used 4 of them rearfacing). We don't use tethers on our seats, so the shoulder portion of the seatbelt comes around the back of the carseat for rear facing - it sort of acts like a tether, and really limits up-down and front-back movement of the seat.

What was also a bit concerning is the video for the use of the angle adjuster - the tech was able to lift the carseat off the backseat in order to put the angle adjuster in.. and so I'm sort of imagining the up-down movement of the seat in a crash? With the euro routing of the seatbelt, there is no way you could get a seat to move up like that after being installed tightly.

Regarding forward facing seats - I've used 2 of them here (european seats). The belt path for one of them is similar to a US seat, except you slide the shoulder portion to a metal loop at the back of the seat - once again, acting as a tether. For the other seat, the belt path is very similar to one that you would use for a booster seat. So in essence, the seat is being held very tightly, as a booster seat, it barely moves at all, and then the child is held by the harnesses.

I realise there are different standards that the seats are tested to, but it worries me that head excursion for the US seats would be too much if used untethered, as in the seat still tests well enough, but how well is 'well enough'?

I am considering buying a Radian RXT, hence my watching all these videos, but I'm not sure about using it without a tether. I read somewhere that using a tether on a US seat could be the difference between a brain injured child and a non-brain injured child... Way to scare us parents!

tiggercat · Dec 3, 2013

Mom_In_SA said:
The video I watched was done by a tech from Diono. I don't think this type of installation is specific to this specific seat, I think all seats from the US have belt paths that are similar?

The seat belt routing that I am familiar with is the european seats (I have used 4 of them rearfacing). We don't use tethers on our seats, so the shoulder portion of the seatbelt comes around the back of the carseat for rear facing - it sort of acts like a tether, and really limits up-down and front-back movement of the seat.

What was also a bit concerning is the video for the use of the angle adjuster - the tech was able to lift the carseat off the backseat in order to put the angle adjuster in.. and so I'm sort of imagining the up-down movement of the seat in a crash? With the euro routing of the seatbelt, there is no way you could get a seat to move up like that after being installed tightly.

Regarding forward facing seats - I've used 2 of them here (european seats). The belt path for one of them is similar to a US seat, except you slide the shoulder portion to a metal loop at the back of the seat - once again, acting as a tether. For the other seat, the belt path is very similar to one that you would use for a booster seat. So in essence, the seat is being held very tightly, as a booster seat, it barely moves at all, and then the child is held by the harnesses.

I realise there are different standards that the seats are tested to, but it worries me that head excursion for the US seats would be too much if used untethered, as in the seat still tests well enough, but how well is 'well enough'?

I am considering buying a Radian RXT, hence my watching all these videos, but I'm not sure about using it without a tether. I read somewhere that using a tether on a US seat could be the difference between a brain injured child and a non-brain injured child... Way to scare us parents!

Again, it is extremely difficult to respond to a video without seeing it myself. I can say that when my radian was installed rearfacing, it was very solid. I did chose to brace and tether it, but even without that it didn't have much movement at all. I think there might be some confusion with the video. You can't place the angle adjuster under a correctly installed seat. You have to position everything properly, but just take out some slack. Slide the AA under the back of the seat until it touches the feet of the detatchable base. Then you tighten the UAS or seatbelt until you have a tight install, with less than 1in of movement side to side or front to back.

We know rearfacing seats with a simple belt routing work very well to prevent injury in the event of a crash. RF tethering, ARB technology, euro routing may have some amount of benefit, but the biggest thing is to correctly use an appropriate seat rearfacing.

I am familiar with euro belt routing on RF seats, as we had some infant seats using such routing. Generally, it was difficult for parents to correctly replicate. I think part of the difficulty is how our seatbelts lock. Many belts have switchable retractors, so the belt locks at the retractor. When you install a RF seat with euro routing, the belt will continue to tighten and mess up your install. Seats would need to have lock offs and specifically direct parents to not switch the retractor to locking mode.

I'm Canadian, and top tethers are legally required on all forward facing seat, so I can't address that part of your post. I wouldn't use a FF seat without a tether.

Pixels · Dec 3, 2013

tiggercat said:
You can't place the angle adjuster under a correctly installed seat.

It is possible, depending on the vehicle geometry.

I have one of my Radians rear facing and it is neither tethered nor braced. No big deal. It is very secure, not going anywhere.

As to not being able to lift the back of a seat with a Euro-routed belt, that's absolutely not correct. I've done it personally. It flips up just as easily as if the shoulder belt was not routed around the back. The shoulder belt only resists downward rotation, not upward rotation.

At any rate, that potential rotation in a crash isn't a safety concern. The seat will not rotate downward excessively, as that is tested for. The seat is designed to not over rotate without the addition of anything extra like a foot prop or Euro-routed shoulder belt. The upward rotation, often called rebound or cocooning, is not shown to be harmful, either.

Head excursion on an untethered forward facing seat (according to US standards) is the same no matter how it is installed. Doesn't matter if the seat is a booster or an untethered harness, the head excursion limit is the same.

tiggercat · Dec 3, 2013

Pixels said:
It is possible, depending on the vehicle geometry.

Maybe I should have said generally. Radians can't usually be rotated towards the rear of the vehicle much because of how the RF boot and vehicle seat interact, at least in my experience.

Mom_In_SA · Dec 3, 2013

Pixels said:
The upward rotation, often called rebound or cocooning, is not shown to be harmful, either.

Head excursion on an untethered forward facing seat (according to US standards) is the same no matter how it is installed. Doesn't matter if the seat is a booster or an untethered harness, the head excursion limit is the same.

Is this upward rotation not shown to be harmful because in a rear facing seat, the harnesses keep the baby down in the seat to counteract it? I guess that would be my concern about an untethered rear facing seat secured that way. Also in a different thread we discussed the different design of euro seats for rear facing, so it makes sense they would move differently in a crash. I would still tether though - a seatbelt holding a seat in one plane would be too little for me.

Regarding the upward movement of the rear facing seats.. I've only tried in with one convertible (I was trying to fish something out that had falled through the front of the seat), but perhaps the degree of movement that we are referring to is different - I cannot get the video to open now, I will post back when it does, but in the video, the tech did tighten the seatbelt after inserting the angle adjuster, so I suppose it wasn't installed tightly in the first place, which is reassuring.

My point about head excursion was tethered vs untethered seats. The head excursion is more in untethered seats. In the forward facing seats here, the shoulder belts act as tethers, limiting the movement of the top of the seats, and hence the heads in them. Whereas tethering is optional there (in the US), it seems to be built into the ff seats here.. and I have to question why it is optional if it "can make the difference between a brain injured and non brain injured child".

I think it's just overwhelming, as an international consumer to look at all the extra safety options that you have listed and just feel mind boggled. Like why does someone get to choose 'safer' options over someone else. Surely there should be the highest standards that all the seats have to meet to begin with and the optional stuff should be comfort and padding and accessories and what not?

MommyShannon · Dec 3, 2013

Some of our rules/laws definitely don't follow best practice. You will see the techs here STRONGLY recommend top tethering all forward facing seats. It's definitely safer.

canadiangie · Dec 3, 2013

I've watched a few manufacturer how-to videos, and I generally chuckle at how simple things appear to be. Based on what you're saying your perceptions are having watched whatever video you watched, I think my best advice is just to erase it from your brain.

Now, a rear facing Radian installed correctly will be quite solid. The further you move from the point of installation the more movement you'll have, but that is the case with all seats - even those that are tethered rear facing will have a smidgen of give at the top, whereas down along the belt path things (can be) rock solid.

I couldn't slip an Angle Adjuster under my installed Radian if you paid me. I can lift it off my vehicle seat maybe 1/4 inch, and that's with me forcing it. Will the seat still rebound during a collision? Yes, of course it will. And a bit of rebound is what we call allowable movement; not unsafe, and to be expected. If you intend to tether your rear facing Radian then it will rebound that much less during a collision.

Here's what I think: when you get your Radian, come back here and we can walk you through the process of installing. If your seatbelts cannot be locked manually we can help you use a locking clip. Heck, I could even have my dh record me installing my Radian with either a locked belt or locking clip and then email it to you.

Yes, this is new territory for you - using a North American based seat, but I promise it is a well made, very protective seat if used and installed correctly.

You've come to the right place for both reassurance and help.

Unregistered · Dec 3, 2013

Are you in South Australia? Do you have a Kia Carnival as they are slightly different to the Sedona layout that is in the US? Do you have isofix points on both sides of the back seat? The gap between these is within the limits for sharing the latch (as long as you aren't using it for either side) and you may get a more secure install due to the lapbelt placement of the middle position of the Carnival (if you are in Aus). If not just ignore my post

Pixelated · Dec 3, 2013

Unregistered said:
Are you in South Australia? Do you have a Kia Carnival as they are slightly different to the Sedona layout that is in the US? Do you have isofix points on both sides of the back seat? The gap between these is within the limits for sharing the latch (as long as you aren't using it for either side) and you may get a more secure install due to the lapbelt placement of the middle position of the Carnival (if you are in Aus). If not just ignore my post

Reference for anyone in the US or Canada reading this -- Kia does not allow borrowing of lower anchors as described. This particular model, which we do not have, may be different though.

Unregistered · Dec 3, 2013

Interesting about the borrowing. In my car manual (Kia Carnival NZ) it states to refer to the child restraint instructions.

Mom_In_SA · Dec 4, 2013

@ Canadianangie : Thank you so much for your reassurance. The videos have not dissuaded me from getting the seat, it was just a bit of a shock to see how much the seat could move, and from what everyone is saying on here, that doesn't seem to be normal anyway.

Remember your words, I might turn out to be quite a pain in the butt once my seat arrives

!

canadiangie · Dec 4, 2013

Mom_In_SA said:
@ Canadianangie : Thank you so much for your reassurance. The videos have not dissuaded me from getting the seat, it was just a bit of a shock to see how much the seat could move, and from what everyone is saying on here, that doesn't seem to be normal anyway.

Remember your words, I might turn out to be quite a pain in the butt once my seat arrives !

Sounds good

Unregistered · Feb 18, 2015

I agree with original poster, the video on Diono website on how to install angle adjustor has the car seat already positioned, and you are supposed to slide the AA under it by lifting the car seat. I installed my Diono Radian with seatbelt, with AA and it toppled over sideways when took a turn quickly. Seatbelt is in there tight, but there is still a lot of side to side movement. Even without AA there is a lot of side to side movement. Obviously doing something wrong. I tried to make sure feet of base are well in to the back slot of the seat, but maybe it's not catching. I don't have it tethered.

Diono Radian RF seatbelt install

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