In Chinese culture there is a very different attitude to copying. What to us is a 'knock off', to them is a recognised skill that has always been applauded. Much of their teaching of painting and drawing is based on practice and more practice till you can reproduce the work of a recognised master.
In contrast, in the west, we foster originality and self expression and rather down play those who paint 'in the style of' or the 'school of' so and so.
And as for making an exact copy, well over here they are deemed to have little 'artistic merit' or are even totally vilified if they cross the line and actually try and pass it off as the real thing.
The difference is said to have something to do with the arrival of the printing press in Europe and its ability, later developed my mass production, to create large numbers of exact copies for little effort and hence they're associated with cheapness and lack of value.
But before the printing press, and far more recently in China, every 'copy' (say of the Bible) was an original and had the same intrinsic value as the one that had been copied.
When you take this variation in culture, an all pervasive drive to make money, a lack of a contemporary legal framework and combine them together with the opportunity afforded by so much manufacturing capacity being handed to them on a plate, then no one should be surprised to see plenty of 'unauthorised' products on the market. Some are identical to the originals in all respects, but the quality does vary. It's a huge problem in the aircraft industry with the sourcing of spare parts. If they can wheedle parts through all that industry's controls and regulations, passing off some bike bits is not going to present much of a challenge.
