So is the entire FS section going to be flooded with Junior Cup Kawis for sale after Jersey? I might have to jump on one of those little pieces of shit. What are the pros and cons of these little bikes to look out for? Any known motor / trans issues? Any mods required to ride the thing hard as far as frame and chassis? Are there magic numbers to stay within for ride height, forks, shock ect? Educate me.
Maybe the info will flow more freely after the series is over... I asked the same a while ago and it was all crickets. Overall I like mine, doesn't handle as nice as my R3 did, but the extra 10 or so HP more than make up for it in overall enjoyment. Hopefully the extra inventory will mean a healthy ULW Endurance for the next few years.
You said Kawasaki and trans issues… I know it’s a stereotype but so they still have transmission issues? Iirc that started on the early 90s ZX6D models where streetbikes would break them… frames would crack often on uncrashed 95-97 ZX6Rs… same engines notoriously threw rods… I only spent two years on Kawi’s 05-06 and absolutely loved their support programs/Team Green and their ZX6RRs… I too had multiple issues that were material failures… internal moving parts breaking that shouldn’t have… my hypothesis on them historically having material failures was that they have lower quality specs on the materials… they are a Heavy Industry company that makes huge machinery mostly where more porous or lower quality alloys may not be an issue… I have no idea about these little bikes but if a few of you get them and make a class of it’s own and sell the show… like a geriatric gauntlet
Junior cup is spec class in 2025 with APX350s https://forums.13x.com/index.php?th...sa-ask-me-anything.387551/page-8#post-6222678
Trans pops out of gear from day one with all of the fixes installed - next step undercutting Front brake is marginal and needs to be cleaned and lubed every day or two to avoid dragging Other than that mine has been a hoot Seems to be an advantage vs RC390 or R3 - hangs with ZX4R better than you might think Easy on tires - not picky about setup I'd recommend
Does R&D out of Florida still undercut and cryo treat transmissions? Or where did you get yours done at? I had one done on a SV 10+ years ago but haven't had one done since.
From what I’ve heard through friends: -popping out of gear. Helps to have gears undercut. -Aftermarket radiator sometimes needed as they can run hot. -front rotor upgrade needed. That’s the main stuff I’ve seen. They are very reliable bikes.
I use spears shock mount to get the recommended ride height in back and near stock fork height I'm on Ohlins 10.5 spring rear GP front 9.0 spring - 170 lb - I haven't tried anything else after getting the clickers where I like them
So, ballpark, how much does it cost to get gears undercut (including R&R), adding an aftermarket radiator, and front rotor? $1K? $2K?
re: shifting issues, mine came with the following and I still have occasions of popping into neutral from higher gears. Not enough to be a big issue. Heavy Duty shift detent Barnet clutch springs Barnet Clutch Plates and Steel plates (1 day on them) Spears shift kit Norton Clutch Springs
FWIW mine was a non-pro trackday build- seems like he opened up the Norton catalog and checked about 2/3 of the boxes. I'd imagine a bike that's been running in the top half of Junior Cup all season is pretty sorted (but may not be exactly cheap)
I used my deposit on a ZX4-RR to buy a Husky FE 350s to dual sport ride, with no regrets. I guessed a well set up 400 twin would be a 'cheaper and plenty of fun' option for a track bike. I'll be considering one myself.
I happen to know one of the front runners Dads. He had at least one maybe 2 400s I believe he’s selling. They’re moving onward next season. Pm me if interested. I don’t think he gets on here. correction https://www.facebook.com/share/p/DBPpp3DZf1cthXFY/? Phils bikes are meticulously maintained.