Originally Posted by
HkCaGu
Thanks! That got me to look further. When I looked up my allowance in the UA website, logged in, it has only two rows: LAX-STT 2 bags free 70 lb each, STT-LAX same. (Meanwhile, Silver/Seaborne's website imply they won't accept anything over 50 lb.)
https://www.seaborneairlines.com/opt...ize-your-trip/
They have a price for 51-70 lb bags, so I suspect it wouldn't be a problem to check an overweight bag through; if UA accepts it, I doubt BB is going to re-weigh it and try to reject it, and it's not clear what exactly they could do anyway, as they're prohibited from charging you a second time for a bag that's already been checked. They could certainly refuse to transport it for weight and balance reasons, but they should still be responsible for getting your bag to you.