GRM just released their tire testing article between the ZII and the Rival, with the Toyo R1R as a benchmark. Summary of it is that the Rival is a BOSS! Great tire at all psi, handles heat well, and they are tolerant of large slip angles. The ZII seems to be a more finicky tire that is more setup and heat dependent.
Now I kind of wish I got the Rivals, but nonetheless I can't wait to run my ZIIs in June
Last edited by dreamdrivedrift; 05-08-2013 at 08:21 AM.