Hi... after seeing the more general threads about getting charged/not charged by various airlines, I looked up Air Canada's policy and found the following:
Bicycles are accepted on a space available basis only and should be pre-registered at time of booking. Each bicycle counts as one piece of baggage towards the maximum number of checked bags allowed by your fare type.
Waivers/Charges
No oversize charge applies to bicycles.
Bicycles are subject to a $50 CAD/USD handling charge (plus applicable taxes) for carriage on Air Canada and Air Canada Express (operated by Jazz only). The handling charge applies to one-way flights and for each way of travel on round-trip and multi-segment flights.
A single fixed handling charge is waived for Latitude and Executive fare customers for travel within Canada, and between Canada and the US. Additional checked baggage rules still apply.
If your baggage count (bicycle + number of bags to be checked) exceeds the maximum number of items allowed by your fare type, additional checked baggage charges will apply, in addition to the fixed handling charge.
Packing instructions
The bicycle must be placed - with handlebars fixed sideways and pedals removed - in a rigid and/or hard shell container specifically designed for shipping or in a bicycle suitcase (in the case of collapsible bicycles).
If otherwise packaged, the bicycle may be refused for carriage. Air Canada is not liable if and to the extent that any damage results from the inherent defect, quality or vice of the baggage.
So, Air Canada seems to split the difference: they won't charge you an outrageous oversize fee, but will charge you something, even if it is a collapsible bike and fits into a regular luggage sized container.
Anybody with experiences with Air Canada? I'm flying with them twice this summer.