i just got off the phone to canadian affair, they told me that thomas cook don't stipulate a weight limit (but that its £30 each way to take the bikes onboard). they also said its 20kg limit, reinforced by this on their website
At the airport
Our UK and Canadian Airport representatives will ensure your holiday gets off to the right start along with the excellent ground staff of Air Transat, Thomas Cook Airlines and My Travel Airways. Check in opens:
3 hours before departure for flights on the Boeing 757 and
4 hours for flights on Thomas Cook & AirTransat Airbus A330 and A310
5 hours for flights on Mytravel Airbus A330
and closes strictly one hour before departure.
Baggage allowances are 20kgs for the hold (unless you are traveling in premium where the allowance is 30kgs) and 5kgs for hand luggage.
These limits are closely adhered to and the airlines will charge for excess baggage at check in.
Top Tip - If you are travelling on the Airbus A330 and feel that you may need more luggage allowance, upgrade to Premium and you’ll receive an extra 10kgs as well as all of the other extra benefits!
i run saint, so the rear mech/chain rings aren't an issue, I'll be sure to protect the other bits where possible though