Has anyone had any experience of taking a bike bag on a National Express bus?
It appears they have one of those luggage allowances which looks like I could get away with it but then again might not depending on what room is left (and whether I ignore the maximum 85cm bit).

Thanks

FROM CONDITIONS
We shall have no obligation to carry luggage in excess of the permitted amount or size but additional pieces of hold luggage, or ‘outsized’ items, will be permitted, subject to space being available, and on payment of a charge for each extra piece. The charges will be £10.00 single journey per item (one journey can be multi-leg) or £15.00 return journey per item. A maximum of three chargeable items can be taken in the hold (maximum 5 overall). Other items must have no one dimension greater than 85cm. Items of luggage significantly in excess of 20kgs may be charged.

I wasn’t charged on a non airport bus, and the bike wasn’t even in a bag! Bus was quite quiet though so the bike could go in the rear compartment on it’s own.

I’ve done it with a bike in a bike bag. I wasn’t charged. Unfortunately, as you say, no guarantee that they’ll take it.