Self Ejecting Child Seat – acceptable?!

I’d be straight on to Hamax and I’ll watch with interest as we use the same seat.

Glad the little ‘un isn’t too badly injured, it sounds like it could have been a lot worse.

I’d love to comment but can see no OP!

Yep, interested here too as we’ve got a siesta and a Baby S #2 is about to be big enough for it.

Yeah, weird…disappearing OP. Basically it said car hit bike @ 10-20mph, seat disengaged from bracket and deposited child several meters away. Minor injuries by the sounds of it.

I can’t see the OP either. It’s not a Zenith seat is it? They were subject to a recall

Edited (sorry)
Got knocked of bike by car, side impact to right side of my bike whilst my 5 yr old daughter was on the back in a Hamax Siesta child seat, strapped in and with a helmet on.
A car waved as out to cross onto the opposite side of the road, as I made out onto the road from the pavement another car came round and drove into us.
I ended up on the tarmac but my daughter’s child seat disengaged from the seat tube bracket and ended up several metres away. Ambulance crew gave her the ok but she sustained a head bruise and several scratched to her legs. Shocked but ok.
Is the Hamax designed to eject on impact and should I contact them?
(I estimate the car was going about 10 to 20 mph)

It was a Hamax Siesta.

Accidently deleted OP on edit 🙁

I think it’s fair to say that it is not marketed as an ejector seat!

It’s not listed in the features http://www.hamax.com/child-bike-seat/classic-collection/siesta

info@hamax.no

which bit actually came apart/disengaged?

The seat has 2 long steel (or allly) rods that engage into a bracket that fits onto the frame seat tube

It means you can have one seat and several brackets. Daughter is within the weight limit too. I tested it out when I got home, if you give enough grunt it pulls out of the bracket without having to depress the big lock button.

Yeah i’ve got a siesta, so did the metal rods come out of their fixing point in the frame bracket?

Are you sure it was inserted properly? just asking the question, i’m sure you’d have checked this.

Hope you’re daughter is ok. did the driver stop?

Edit: just seen you’re post above, sounds like the bracket could be faulty. I haven’t tested mine out like that and have given it to my BIL so i’ll get him to check it out.

I’ll give ours a test this evening and report back.

Being hit by a car is not likely part of safety design brief.
Just an accident and glad the kid is ok!

I’ve got another bracket, fairly unused one too so will test that out if I can find it tonight and report back too.
My daughter is ok but I think it’s fairly unlikely she’ll be willing to get in the seat again!
The driver did stop and gave me his insurance details and number. Police took a report too so that’s all covered.

Ah good, i’d definitely be dropping Hamax and email though.

I had an issue with the fixing bolts when i first got mine and they were very good at sorting it out.

A car waved as out to cross onto the opposite side of the road, as I made out onto the road from the pavement another car came round and drove into us.

Never ever trust someone else.

Yeah, classic mistake.

This is why i won’t take my child on the road. I fully expect to be knocked off my bike one day & would prefer it if my child wasn’t involved.
Glad you’re both ok though.

Plenty of adults commute with their kids on the back round here, pays to super careful.

I’ve had a good look at our Humax Siesta and tried to recreate the failure. I’ve not crashed into it at 10-20 mph or done anything I thought might damage the seat so this test should not be considered exhaustive. My efforts were limited to a combination of twisting, pulling and a good firm jerk from a number of angles whilst the seat is attached to the bike. I then took the clamp off the bike, attached the seat and ‘smacked it about a bit’ whilst repeating the above to try and get the spring-loaded button to activate.

The attachment mechanism in general appears robust and unlikely to fail if everything is in good order and setup right. Assuming the prongs are inserted correctly and squarely and the positive click is heard, I can’t make the seat come out without a firm and intentional press on the square metal release button. The locking plate is firmly engaged in the grooves on the seat prongs and there’s no movement in the system.

Where I can see potential for an unintentional eject as described by the OP is if the clamp is not fitted tightly and correctly to the seat tube. The mechanism works thanks to a metal spring compressed between the square metal release button and a plastic plate inside the clamp. As the four bolts are tightened around the seat tube, the spring is compressed and the mechanism becomes stable. You can see this as the square release button is held firm by the spring acting against it. If the four bolts are not tight there is play in the mechanism and the seat is not held anywhere near as securely.

One potential way the bolts could seem tight but not be is if the nuts into which they screw are not correctly seated in their grooves. I managed to tighten the bolts with the nuts at 90 degrees to the grooves. A sudden jolt caused the nut to jump down into its groove, the bolt was no longer tight and there was play in the release mechanism.

Our seat is not heavily used and the components of the mechanism show no signs of wear. They seem like pretty hard steel that would be difficult to bend, round off or wear down. Have a look at yours though as any damage there could reduce the holding power.

All considered, I’m confident that our seat is OK and will happily continue to blast around with #2 in it. I’m definitely interested to hear from others and how the OP gets on with Humax, please do keep us informed.

I hope your daughter heals fast OP 🙂

Thanks sturmeyarcher, appreciate your efforts.
I’m pretty handy mechanically with bikes, the clamp is very tight, otherwise it turns on the seat tube and it regularly checked. I think as I use it frequently there maybe the opportunity for wear to affect the safety of the locking mechanism.
It is possible a car impact may provide sufficient force to cause the seat to eject?
Anyway, thanks for all the support regarding my daughter, she is now keen on me getting a kiddyback tandem, at least it won’t have an eject mechanism, got to get her back into bikes somehow.

This is why i won’t take my child on the road. I fully expect to be knocked off my bike one day & would prefer it if my child wasn’t involved.

I do hope that you live in a bungalow, as I can guarantee that one day your child WILL fall down the stairs.

Just to clear up my understanding, she wasn’t ejected from the seat, but the seat came away from the bike on impact and she ended up still in the seat, but not attached to the bike?

TheGingerOne – she wasn’t ejected from the seat, the seat came away form the bracket. I got to watch her skid up the road strapped in, luckily she was left side down.