Does anyone know what the weight limit is for bike bags on Lufthansa flights?
I can’t find it on the website.
Thanks in advance.

Generally part of your luggage allowance these days. Normally buried in the baggage T&C’s

Basic rules
Sports baggage is carried free of charge** under the free baggage regulations (number/weight of bags).

Registering sports baggage: up to 24 hours before departure via the reservation hotline (+49 (0)69 – 86 799 799). Please specify your booking code.

Exception rules for sports baggage
1. The sports baggage exceeds the free baggage allowance but not the maximum weight. The rules and prices for sports baggage apply (see above) Also read here http://www.lufthansa.com/mediapool/pdf/31/media_1155483331.pdf