It looks like Easyjet have changed their T+C's for bikes. Here's a copy of what I've just read:
Sports equipment – how does it work?
Sports equipment includes small items suchs as golf bags, ski bundles (skis and ski boots), snowboards, diving equipment, paragliders, pole vault poles and firearms. It also includes large items such as bicycles, canoes and hanggliders. There are separate categories of weight allowance and fees for small and large items.
Adults and children can bring one item of sports equipment in addition to the standard allowance of three items of hold luggage per passenger – please note that each piece of hold luggage has a fee attached to it. Infants don’t have a sports equipment allowance.
Sports equipment items have different weight allowances and charges
For weight allocation and pricing, we divide sport equipment into two categories: small sports equipment and large sports equipment.
Small sports equipment (weight allowance 20kg)
Small sports equipment items include golf bags, skis and boots (one charge), snowboards, diving equipment, paragliders, pole vault poles and firearms. Sporting/competition firearms are subject to limitations.
Large sports equipment – weight allowance 32kg (except bicylcles at 23kg)
Large sports equipment items include bicycles, canoes, kayaks, windsurfs and hangliders.
Six large sports equipment items only per booking
There’s a limit of six large sports equipment items per online booking – even if there are more than six passengers on the booking. If you wish to carry more than six items, please call Customer Services.
You can’t buy additional weight for sports equipment
It is not possible to purchase additional weight for sports equipment online. If you go to the airport with a small sports equipment item weighing more than 20kg you’ll be charged an excess weight fee.
You can ’pool’ your sports equipment weight allowance
If you purchase the right to bring an item of Sports Equipment, you can ‘pool’ the weight of this item with your other hold luggage.
So it seems that the max weight for a bike is 23kg unless you pool the weight with your 20kg hold luggage.
Was a bit of a shock when I went to book a flight.