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_name_78 ( rider VARCHAR, speed VARCHAR )

### Question ###
Which rider from the 1971 Isle of Man Junior TT 250cc final standings had a speed equal to 86.15mph?

### Accurate SQL ###

SELECT rider FROM table_name_78 WHERE speed = "86.15mph"