ALR/ELR seat belts retrofit

[lokkju]

Hello all

Till last week I was using my VW to transport the kids and I was very happy user of ALR/ELR seat belts mounted in the back seats. Can you imagine my disappointment when I discovered that I only have standard ELR belts in my brand new used X5 that replaces the good old VW?

Hence my question. Has anyone tried to retrofit rear seat belts equipped with newer retractors? I reckon that it's not as simple as unscrew, swap, put back together. There may be no sensors in the buckles but there may be detonators perhaps, and that means that if swap is done incorrectly it will result in decreased safety instead of increased. I'm not quite sure yet and I'm hoping for some reasonably creative answers.

As far as I know nobody here mentioned it before, or at least I failed to find anything with my key words. I hope I'm not duplicating any topics.

Peace.

[X5Sport]

ALR systems are old hat and have been replaced by ELR, and with kids seats by ISOFIX and iSize mounts with or without top tethers.  Once they are over the height/weight limits then a standard ELR seat belt should be fine.  Why would you want the old type?

In addition, it will almost certainly invalidate the type approval for the vehicle and therefore you will need to get it tested with those belts.  Your insurers will also want to know and be certain that all is well and the risk of injuries is not made worse.  Breach of type approval invalidates use of the vehicle on UK roads.  You will need to have a very careful read of the Vehicle Construction & Use Regulations, EU Type Approval Standards and the BMW Type Approval for the E53.

[lokkju]

Perhaps I misunderstood - correct me if I'm wrong - but from what I have read, ELR is the one where you are allowed to pull any length of the belt at any time and retractor only blocks when the belt is pulled with sudden excessive force (i.e accident or user trying to pull it too quickly).

Whereas ALR is the improved one where retractor blocks if one of following occurs (depending on actual make/model): user pulls certain length of the belt and the lock is being engaged at the "stop" point allowing you to only retract it, to pull more you have to allow the belt to go back completely and start over and pull more this time; or (as I had in VW) you are free to extract as much as you like at any point but once you extract all of it, it engages the lock and from that point you can only retract.

Actually I don't suppose you will ever have ALR only, you will always have mix of both (ALR/ELR), so ALR reacting also to excessive sudden force. And that is what I want to fit as my child seats do not have ISOFIX.

My X5 belts only react to sudden force therefore I class them as ELR and I'd like to fit the "better" ones that have the additional locking mechanism, perhaps from a different bimmer. And my only worry (because I haven't yet took the back seats out to check) is that there may be a wire connected to the retractors to engage a detonator in case of accident, which is a desired safety feature. And if I ignore it and mount ALR from another car that a) does not have a detonator whilst I have it or b) has different connection that I can't work out, then I will loose that feature and potentially decrease safety. However if there is no electrical connection between computer and rear seat belts, I am free to fit whatever belts I like as long as I make sure they are safely and firmly attached to the car. And by "free" I don't mean the legal aspect, I'm just looking from purely technical point of view. I'll look at the legal side once I know it's technically possible. But worry not, I will drop the idea if it turns out to be impossible or too complex or not worth the effort in any way.

[lezmtaylor]

I have no idea,but a good ,explanatory post as to reasons and why's and how's, will look forward to answers with interest.

Lez