I have an 03 zx6r, my brother an 04 gsxr600 and my dad an 01 busa.
I've rode all three back to back to back. We'll tackle straight lines first. I can get the 600s off the line quicker but by 50mph, a sonic blast of blue silver knocks you over and disappears behind the horizon before you can finish 3rd gear. Bring on some tight twisties and me and my brother will get a nice breather at the end before the busa catches up.
But you all should know this. Lets talk zx vs gsx.
zx stock gearing is 15/40 and gsx is 16/45. 6th gear roll on 60-80 the gsx will pull the zx. I way 200lbs and my brother 165. We switched bikes and tried again. Even with my heavy ass the gsx pulled, but only slightly. A quick switched to 14/40 gearing on my zx evened things right out. They both rev to 15,500, but once the zx gets cooking I think it pulls the gsx a bit in the mids say, 9-12k rpm and up top its pretty damn even. The only power mod on the zx is an akrapovic carbon slip on and the gsx has no power mods.
In riding positions, the clipons feel lower on the zx than the gsx. The gsx feels slightly narrower with a more upright riding position.
I felt more comfortable railing the zx around than the gsx but thats just because I'm used to it.
If I was in the market for a new 600, I would get....whatever they would sell me the cheapest, between the zx and gsx. Ive sat on an R6 and didn't really like the feel of it at all. I've never tried the honda 600rr.
Edit: I don't know anything about 05 yet, but If was to guess. Kawi will redesign the 6 to look like the 10, ala cbr 1000rr and 600rr and gsxr1k and 600.
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