Track slap

[Jemeda11]

I have a new 2011 summit 154. i used to ride a 2001 summit 144 . I have what i call track slap its hitting the tunnel or something? I have not encountered this before but i rode a buddys summit 146 and his does the same thing . is this normal??? thanks for any advice or help or the cause of this.

 

[Sitruk]

Try tightening your track and see what happens. They will slap / chatter if they are too loose.