Riese and Müller is the inventor of the Birdy and also the manufacturer of the models for the western parts of the world. The frames are produced by pacific cycle and they produce and sell the Birdy in Asia. Specs may be different between the two as the product lines are independent from each other apart from using the same frame and the same name. The deal with Pacific Cycles regarding manufacturing and market-areas dates from the very beginning of the Birdy in the nineties when they were looking for some funding to start production and Pacific Cycles stepped in to help them with production of the frames, getting the right to serve the asian market with Birdies in exchange.

So depending on in which area of the world you are living Birdies may be speced differently.