Same here with Sleazyjet. No real drama but equip yourself with their T&C's. BIKES DO NOT ATTRACT ADDITIONAL FEES. It takes careful reading to find it though but it does say it in there, along with max 50kg total per passenger and max single item 32kg's. I deduct therefore (and had Esayjet customer services confirm it in writing to me) that your bike bag can weight up to 32kg but your total luggage weight cannot be over 50kgs.
I love it when they ask "have you let your tyres down ?" and I answer "Why, does the pilot let his down after we take off?"