Originally Posted by alfaholik
This weekend one of my front tyres burst because the inside was worn straight through... while the outside and middle of the tread shows about 7mm..

Not nornal at all - Wrong tyre pressures, Worn bush(es), broken spring(s) or misalligned traking or a combination of all.
Tyre wear has been fairly even on both my 166's - My 156's wore slightly on the inner edge but not to your extreme!