I've just gone through the pain of purchasing new tyres for my KX-S. In the end I settled on the Bridgestone D400's because I've had no trouble with them regarding wear, noise ..etc.. I considered the ADVAN ST and in fact they were cheaper than the D400's but the oversize tyre may cause more problems. I was told to watch out for the front tyres rubbing on full lock as there's not a great deal of room under the front guards. This can be fixed but added more cost. From a pricing perspective, the D400's were quoted by three of the larger national tyre chains at $550, $515, $489. Next I tried a smaller independent tyre shop called "King of Tyres" at Baulkham Hills (Sydney). They said $450 each - SOLD!! The best price I got on the ADVANS was $437 by JAX Tyres. just a side note - beware of the "king of tyres" they have a hills district reputation as the "kings of wheel nuts left off car". Too many times i have driven past only to see a car up the road from them missing a rim, and it has happened to a guy i now live near, from the same shop... moral is - Check they're on tight yourself. That's great info Guys....never used King of Tyres and they are only 5mins drive from me! Lucky I don't like lose nuts! Do you know what you have to do to the front guards to fit the Advans? Because the rubber thats on there at present does not phase me either way, I think they are a pretty average Tyre :o