My friend got his Dawes SST-AL today and it was riding fine for awhile, then all of a sudden he starts up for a ride when the light turns green and as his cranks are at 12 & 6 (right foot, dominant foot at 12) he tries to pedal, the pedal at 12 goes straight down. he said it feels like it just slips down to 6. Im guessing its either the bottombracket or his lockring isnt tightened. any insights?