question about tires

[RustyStunts]

i have a 400ex and 450r...can someone please tell me the size of the small tires everyone uses for mx in th rear...everyone at the track keeps tellin me to get smaller tires cause i run stock ones...now will these little tires fit on my stock rear rims???if so can someone please give me the sizes of these tires...i know this is a rookie question im sorry im new at this :)

[Colby@C&DRacing]

18x10x9 is a common size for MX. they will fit your stock rims. 18" is the height 10" is the width and 9" is the rim size. The width can vary but you will need the last number to be a 9 for the rim size you have

[RustyStunts]

Originally posted by Colby@C&DRacing
18x10x9 is a common size for MX. they will fit your stock rims. 18" is the height 10" is the width and 9" is the rim size. The width can vary but you will need the last number to be a 9 for the rim size you have

thank you..god bless ride safe!!