That Object file is extracted from a very high detailed CAD Modell. Originally it was ~ 50 MB, now its just 5 MB, but still takes long to load.
By the way: The normal method of loading Object-Files from the /res/raw folder works for us also with files bigger than 1 MB, but it takes quite a while. If we just load the seperate file-parts through the serialized method it works fast for single parts, but sometimes we get an memory out of bound exception (not reliable reproducable).
What exactly is the serializer doing? Is it just a thing of parsing the xml-stlyle .Obj file, loading it into your object presentation data-structure an writing that almost 1:1 as binary down?