One reason that I use bicycles is because I do not want my audiences questioning the validity of the cards.
I think magicians are the only ones perpetuating this idea. In more than 5 years I have never been questioned for my cards and I use custom designs exclusively. And I've used all kinds of different designs. Black cards, white cards, alternative artwork, so on. My only requirement is that the pips and indexes are obvious to understand.
If you go to Target, WalMart, Walgreens, CVS, Bicycle.com, heck even liquor stores half the time, you'll find a variety of custom designs. Brand cards (Like Jack Daniels), sports teams, cartoons, animals, locations, trivia - custom designs are no longer even remotely unusual. Rider Backs do not have the monopoly they once had. David Blaine uses his own brand of cards and no one questions him.
I don't think your average audience is going to question the validity of your cards because they're not Bicycles, unless you (as in the performer, not a specific person) prompt them to question it, or if they're the type of person who questions everything a magician is holding.
I will also note that the one, single time I have ever been asked if I was using a trick deck, it was red Rider Backs.