Unless its an "international" field...then any frames are allowed provided they pass an NJS inspection.
DW What bikes are allowed in the Keirin event depends on where it is taking place. In Japan, where the activity is alligned with nationwide gambling on the race results, only steel lugged frames are allowed, not a LOOK in the bunch. Some frames are very slightly fancier than others, but I believe everyone making these would have KOF status.
Dennis Young
Hotaka, Japan