Multi-tech as a booster - question

I'm in the process of making a couple of decisions re seats. One of these is whether or not I'll use the MT as a booster.

I like the idea of a LATCHable booster, because it just seems to me that in the event of a crash, the weight of the untethered booster would add forward force to the child. (The MT does not have a top tether).

So, can anyone tell me why I shouldn't consider using the LATCH belt from another restraint to secure the MT in booster mode.

I'm after a physics type response here, rather than "because it hasn't been tested like that and it's not part of the seat" - I appreciate that point, but am more interested in the nuts and bolts of why I shouldn't. (I've never been good at accepting "because you can't" - I always want to know the reasons).

In essence - is it safer to have a booster move with the child in a crash, or for the booster to remain put?

OK, so after posting this I went and had a look at the seat, and I don't think there is actually a path which I could run a LATCH belt through anyway. (sheepish grin...) SO, can we please have this discussion anyway, but not specific to the MT? I'm still curious. Thanks!

I'm sorry, but the answer really is 'BECAUSE YOU CAN'T.' LOL.

We are not privy to the private testing the child restraint manufacturers do to their child restraints. They might have tried some sort of LATCHing system and discovered it had a deleterious effect on child passengers.

'Rigging' something up is an extra layer of egregiousness....you never add a component to a child restraint that wasn't designed to be used with that restraint.

As an aside, the Canadian tests awhile back indicated that rigid LATCH may increase abdominal load, although Clek believes rigid LATCH improves side-impact ratings.

However, there is no indication that soft LATCH has any positive effect on the passenger. Flexible LATCH is only to prevent the booster from becoming a projectile when it's not buckled in.

There is nothing to be gained by 'adding' flexible LATCH to a booster in terms of safety....and quite possibly a LOT to lose.

Multitech weighs about 10 kg so I assume that it is heavier than regular Australian boosters. this is because of the supportleg on the back. It moves more in a crash. I would use a dedicated booster seat.

Boosters with isofix result in the booster staying put, which is safer than having some movement.

When a booster is anchored with isofix (rigid LATCH) the outcome in a frontal crash is that the child´s rearend stays far back wheras the upperbody goes forward. This reduces the loads on the neck, as the back of the child can follow suit.

In a booster seat the isofix system only holds the seat in and prevents it from moving forward in a crash. It won´t move very far anyway...

Sideimpacts is where you see the benefits of isofix as the rigid system helps keep the child and the seat at a good distance from the door panel thus minimizing the risk of contact with the car interior.

Multi Tech is approved forward facing until 25 kg so it's fine to use. Most parents use this seat for it's long rear facing time and then buy a dedicated high back booster seat when times come. A HBB weigh less, is cheap and is easier to move. This would apply to all combination seats, not just MT.

Using a rigid Isofix seat is the safest way for an older, 4 and up , child to travel forward facing (except for rear facing of course). Reason is not really that a child behave differently in such a seat but forces on child are lower.

An Isofix seat is tightly secured to chassi of car which means none of the weight of the HBB is moving forward pushing child in the back during a collision. Seat belt can of course handle any of these extra forces pushing forward but it's more force on the child.

Side impact protection in is slightly better for an Isofix seat just as Lena says. Big problem with forward facing seats is that SIP is terrible due to pre-impact breaking which occur in a high percentage of accidents.

You know all those crash tests where the camera catches child sitting still and head being protected by the "wings"? You can pretty much forget about that since collisions in real life are much different. This is one large reason why RF is so superior for older kids as well. A child in a RF seat is pushed further into the seat during a collisions thanks to pre-impact breaking which offer great protection.

Maedze said:

I'm sorry, but the answer really is 'BECAUSE YOU CAN'T.' LOL..

Click to expand...

LOL seriously though, thankyou, at least you gave a valid reasons to back up "because you can't"

Thanks AD and Lena. Yes, am aware of the impact of pre-braking on SIP, (which is why my views on headwings are that they make great headrests for sleeping...)

You've confirmed my thoughts re WHY I actually asked the question in the first place. I just can't get my head around the extra weight behind the child.

Thanks all, the result is that when the time comes I'll use a dedicated HBB, and/or the Frontier which is LATCHable. Besides, DS is already 23kg.