I have flown twice with Ryanair in 2017 and August 2018. Paid Normal sports equipment for below 20 kg 140x45 Pro limit lightest bag. Actually asked at the airport check in and guy said that large would "probably" give me up to 30 kg. Not sure he knew exactly though.That was not the guy who actually takes your bag , just a check in guy.
Anyway worked for me for my board two kites, harness etc at around 19 kg