(i posted something similar on other forum, but think it is best suited for here. sorry if a problem)

flying TLV-FRA , FRA to america RT. the segments to/from FRA-TLV are on LH, the other flights on US. it is a US award ticket.

US allows a carry on of 40 lbs (is this correct? i was told this on the phone, and online, i didn't see a limit) LH of 8 kg. if my carry-on is more than 8kg when i leave FRA, for TLV, will LH make me pay a fee, given i am on US ticket and coming from USA? And am i limited then to 8kg when leaving TLV on LH?

What happens if carry-on's wheels don't fit in that little measuring box at the airport? and what happens if this is on connecting flight where it made it thru for the first flight? are you charged as an additional bag? (my carryon is allowed on LY flights, but AF said it didn't fit)

thanks.

Which part of your itinerary is on a "code share"?

In any case, LH rules will apply to all LH-coded flights, and US rules will apply to all US-coded flights.

youre' right, not a code share. an award ticket.

in this case, i get the worst of each policy.

if i take a an extra bag, and pay US for it, will i have to pay LH also? i presume i check in my bags only at departure, and not again in FRA, so i am guessing not, or should i say, hoping not!

It's much worse than that. They will make you throw out items until you get under the weight limit (though they typically only check at the check-in counter, and not when connecting). It's a true hard limit - absolutely nothing "heavy" allowed. (I had this happen on IB once.)