I second this.
Myself, I would like to attempt this cross but am interested in how it turns out before I do it. Someone else be the guinea pig lol.
You should ask the people on here http://www.backyardchickens.com/t/727364/a-bielefelder-thread/1070
One of my Cream Legbar laying her 1st egg today. The Bielefelder male isn't old enough. I expect to breed some cross this summer as I don't have any Bielefelder hen .
You won't get a bielefelder hen if you cross them. You'll get a mutt.
I know this is an old thread, but since I'm planning on doing a cross, I thought I'd just throw in my two cents worth.
The term "mutt" is truly a relative word. The term "cross" is much more specific, as that is what you are doing when you breed two different breeds together. As an AKC dog show judge, I can assure you that many, many of our popular breeds were created by "crossing" other breeds and selecting particular traits to carry on. The Bulldog, the French Bulldog, and the Boston Terrier are all very closely related. Are they mutts? Of course not, they breed true. But many generations back, the Frenchie and the Boston could be considered "mutts" but in truth they were a work in progress in developing a new breed.
Take the Labradoodle (not an AKC breed, but they breed true) - a specific blend of Labrador Retriever and Poodle (in all three varieties) originally bred as a hypoallergenic service dog. The size differences coming from the Poodle were an added benefit as there are many disabilities that do not require size to do their work. Could a "mutt" also serve as a service dog? Absolutely, but why stamp the animal with a derogatory name? I think a "terrier mix" or "shepherd mix" is more respectful.
I'd like to regard "crosses" of chickens in the same way. To me they are not "mutts" (unless they are simply "barnyard mixes" with no specific idea in mind of what you want to accomplish with the conformation of the bird or the egg, then they are simply just that - "barnyard mixes"). To me, they are an experiment in developing a new breed. The two crosses I have in mind are Biels/CL and Biels/BCM. What do I hope to accomplish? Keeping the docile, friendly temperament of the Biels, hopefully with autosexing and with the resulting eggs being jumbo dark brown (with the BCM) or jumbo mint green (with the CL).
Will it work? Only time will tell, but I will never consider the chicks "mutts"!