What is the maker and year of this frame with the serial number a2008112 I'm needing help identifying my frame with serial number a2008112 please help
You can easily identify the maker of this bike thanks to the gusset on the frame, it is a Mongoose.


The serial number starts with A, which tells you it was made in January (A : January, B : February, C : March, etc.). 
Then the second character is a 2, which means it was made in 1982 (last number of the year).


So your bike is a 1982 Mongoose.
According to the manufacturing date, it can either be a Supergoose I or II, or a California Special, but I can't really tell with these picture. You would also need to know the frame material to help figuring this out.

If you need more info, hit that link : http://www.vintagemongoose.com/index.php