I haven’t tried Ryanair yet, so let me know how is it going if you try. Uni usually is bulky and in strange shape, but my uni luggage was usually quite light.
I was flying with Lufthansa and Eurolot and nobody cared that it is oversize (even for checked-in luggage) as long as it was in the weight limit.
Here are my experiences:
(29" wheel in a separate bag), frame and seat in the big backpack. Someone told me to declare that’s a circus prop and not a bike (to avoid paying extra charges…)
-ALITALIA (some times): no charges
-LUFTHANSA (2 times): no charges
-CHINA EASTERN AIRLINES (4 times): 3 times no charges (even if I passed the maximum kg amount permitted), once I’ve paid 30 euros…
-TURKISH AIRLINES (2 times): (even if I passed the maximum kg amount permitted)
Twice, after Xray inpections, they asked me to open the bag and show them what was inside…
Once the seat-seatpost was misdiagnosed: from the Xray they thought it was a hammer…