As skoot's says: BA and virgin will let you take bikes on for free, the cheaper airlines will make you pay. Check on each airlines website.
I'd advise against trying to disguise the bike as normal luggage. I'm guessing it's more likely to get damaged as the bag handlers are less likely to throw a bike bag around than just a normal bag full of clothes. And If it does get damaged you'll stand no chance in geting any sort of compensation.
As skoot's says: BA and virgin will let you take bikes on for free, the cheaper airlines will make you pay. Check on each airlines website.
I'd advise against trying to disguise the bike as normal luggage. I'm guessing it's more likely to get damaged as the bag handlers are less likely to throw a bike bag around than just a normal bag full of clothes. And If it does get damaged you'll stand no chance in geting any sort of compensation.