Only under pain of death put on Z4s. The tyre dealer, in this instance, was a total feckwit. Z6s are far superior and seem to suit the SV nicely. The Pirelli Stradas are the same tyre but with a slightly different tread pattern. You might also wish to consider the Conti Road attacks
(unless you live in Kent where, for some reason, they don't handle quite as well 
).
.