Below is the list of tables from the database along with their columns and datatype. Need to generate an accurate SQL query for the question.
Only use the columns present in the respective table. Only use the columns which are required to generate the SQL query. Only use table joins if required and not otherwise.

### Tables ###
TABLE: CREATE TABLE table_25589 ( "Stage" real, "Winner" text, "General classification" text, "Mountains classification" text, "Points classification" text, "Sprints classification" text, "Team classification" text )

### Question ###
If the winner is Bernhard Eisel, what is the stage maximum?

### Accurate SQL ###

SELECT MAX("Stage") FROM table_25589 WHERE "Winner" = 'Bernhard Eisel'