I lowered the pressure to 36 at the recommendation of Dan at Traxxion. He explained that the high pressure Kawasaki was specifying was to try to compensate for the...umm..."manly" size of the C14. That and the "too stiff" front springs that come stock are the reason that the front tires chew off like they were made of eraser rubber.
I don't think it is a design flaw, just a spec based on the type of bike and its weight.
Agreed, the lower pressure will likely make for some amount of uneven wear and shorter life, but isn't really an unreasonable number.
I have read a lot of posts over the years about people who lowered the pressure and ended up ruining their expensive tires. So I tend to warn whenever I see someone doing it (especially someone new to the bike). At first, 42psi sounds shocking, but it really does work correctly for this bike and most tires.
I don't have a copy, but believe that Kawasaki lowered the recommended pressure to 39 in the newer models.
Well, really nothing has changed on the bike that would affect tires much- it is the same weight, same wheels, same distribution, same suspension design, same bar/seat location, same rake angle, same wheel positions, generally the same suspension settings. 2008 all the way through the 2013 user manuals call for 42psi. Yours is the first mention I have seen anywhere about any type of possible recommendation change by Kawasaki. Now that we have someone with a 2015, we can ask elp_jc to check his manual.... but I would be SHOCKED if it didn't say 42psi.
The PR4 GTs that are on the bike have 3K on them at 36 PSI, and have only begun to flat spot in the center, so at my speed, mileage doesn't seem to be a big worry.
I hope not. Keep in mind the PR4GT is quite possibly the best matching tire for the C14 yet (for general purpose) and it is designed to have a longer life than any PR before it (while maintaining the grip). Perhaps if you were running 42psi, you would already have seen less wear (although usually it is not the exact center that starts to suffer with lower psi, so perhaps not).
Thanks all for your input. As a group, we have an amazing amount of knowledge...and it is wonderful that folks are willing to take their time to share.
Love the Forums- it is a great place to gather tons of information and share experience. I will say that I tend to suffer a lot from back/shoulder/arm issues, and after adjusting the bike height, seat, and bars, the thing that made the most difference for me? Back exercises and strengthening my core muscles (abs/back/sides/etc). I *hate* exercising, but I have to admit it is important/effective and I am reluctantly suffering through it... (getting older sucks, things used to work so much better/easier).