Why are bike rear rack weight limits so low?

[FlatSix911]

I know that the rack manufacturer Tubus intentionally limits the weight capacity 26 kg. to prevent their racks from being automatically approved for use as a mount for a child seat:
"ISO 11243:2016 requires that all luggage carriers with a carrying capacity of 27 kg or more automatically be approved for the attachment of child seats, too." But they test some of their racks up to a load of 40 kg.

This is the correct answer.

Tubus has artificially limited the rated capacity to reduce their liability with child seats. The actual capacity is much higher and listed in parentheses for each rack.

This must be it, or some version there of. It regulation and lawyers. Can't go over 28 mph and cant load more 55 lbs on the rack, because you're stupid, and we're the government and we know what's best for you!

Company - Tubus

* ISO 11243:2016 requires that all luggage carriers with a carrying capacity of 27 kg or more automatically be approved for the attachment of child seats, too. In our opinion, transporting children on luggage carriers is dangerous, so we voluntarily restrict the carrying capacity of tubus luggage carriers to max. 26 kg, thus excluding the attachment of child seats and/or the transport of children on our carriers.
This restriction has only the legal reasons mentioned above. tubus carriers are still tested with considerably higher luggage loads (which are specified for each product in brackets).

 

[PatriciaK]

My mechanical engineer spouse says most major-brand hitch-type bike carriers are over engineered.

 

[FlatSix911]

My mechanical engineer spouse says most major-brand hitch-type bike carriers are over engineered.

Agreed... I think the OP was inquiring about rear-mounted bike frame racks.

 

[PatriciaK]

Agreed... I think the OP was inquiring about rear-mounted bike frame racks.

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Brain cramp - sorry!

 

[FlatSix911]

Brain cramp - sorry!

No worries!