CREATE TABLE table_29218221_2 (rider VARCHAR2, tues_31_may VARCHAR2)

What is the number of riders that had a Tues 31 May time of 18' 55.91 124.236mph?
SELECT COUNT(rider) FROM table_29218221_2 WHERE tues_31_may = "18' 55.91 124.236mph"
SELECT COUNT("rider") FROM "table_29218221_2" WHERE "18' 55.91 124.236mph" = "tues_31_may"