April 16th, 2021, 12:07 PM | #1 |
NinjaBraap
Name: Tom
Location: Long Beach, California
Join Date: Dec 2016 Motorcycle(s): 06 Ninja 636, 2016 Yamaha R3 (Street/Track), 2019 Ninja 400 Project Racebike Posts: 175
Blog Entries: 2
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Ninja 400 Stock Springs
Hey Ninjettes!
Been a bit since I was on here since I went from the Ninja 250 to the R3, which I've been very happy with. However, I managed to snag a crashed Ninja 400 for cheap, and am aiming to race in SoCal. That said, I still have two R3's, one street/track and one that was going to be my racebike, and may still be my B bike if funds permit. Now onto the main topic. A fellow racer who had a pretty awesome first season as a novice racer at CVMA this year, placing a good number of 1st and 2nd places, crashed last round due to multi-racer pile up, and I managed to get some parts off the crashed bike since he opted to buy another one before this weekend's final round as he had a shot at winning the championship. One of the things I realized looking at Racetech's suspension calculator and parts nubmers, is that the spring rate for the Ninja 400 is .77kg/mm, as opposed to the R3's .65kg/mm, and Racetech recommended .78kg/mm for my R3. Since they're both 41mm forks, with similar fully extended lengths, and the racetech spring part numbers are the same for both bikes, I snagged the Ninja 400 springs for my R3. All I had to do was cut new tube spacers (which I just cut from the Ninja 400 tubes I got with them). However, my friend said he'd never touched the forks on the 400 he crashed, but the springs were progressive, which is cool but I can't find anywhere wether that's how it actually comes from Kawasaki or if they're aftermarket springs. The parts diagram doesn't show progressive springs, and every time I try and locate any info, it's all aftermarket talk and info. Does anyone here know if they come from the factory like that? Sure, I could just pull my 400's springs, which I will when I install my pre-load adjusters, but those will take a moment to arrive, and I miss this group so I figured I'd make a post.
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Racer, Mechanic, Enthusiast. Vendor for Norton Motorsports Subscribe to my Instagram and YouTube: Instagram YouTube Last futzed with by NinjaBraap; April 16th, 2021 at 03:58 PM. |
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April 16th, 2021, 03:43 PM | #2 |
ninjette.org dude
Name: 1 guess :-)
Location: SF Bay Area
Join Date: Jun 2008 Motorcycle(s): '13 Ninja 300 (white, the fastest color!), '13 R1200RT, '14 CRF250L, '12 TT-R125LE Posts: Too much.
Blog Entries: 7
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Good question - will bump it to the tech area for more views and hopefully some useful responses.
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Montgomery Street Motorcycle Club / cal24.com / crf250l.org / ninjette.org ninjette.org Terms of Service Shopping for motorcycle parts or equipment? Come here first. The friendliest Ninja 250R/300/400 forum on the internet! (especially Unregistered) |
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April 17th, 2021, 08:43 AM | #4 |
EX500 full of EX250 parts
Name: Bill
Location: Grand Rapids-ish, MI
Join Date: Jul 2012 Motorcycle(s): '18 Ninja 400 • '09 Ninja 500R (selling) • '98 VFR800 (project) • '85 Vulcan VN700 (sold) Posts: A lot.
Blog Entries: 1
MOTM - Aug '15
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Yes, the stock fork springs are progressive. I thought I took some pics when I swapped in my RaceTech springs, but I can't seem to find any.
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*** Unregistered, I'm not your mom and I'm not paying for your parts, so do whatever you want with your own bike. *** |
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August 12th, 2021, 02:55 PM | #5 |
NinjaBraap
Name: Tom
Location: Long Beach, California
Join Date: Dec 2016 Motorcycle(s): 06 Ninja 636, 2016 Yamaha R3 (Street/Track), 2019 Ninja 400 Project Racebike Posts: 175
Blog Entries: 2
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As a follow up now sometime later, here's what I've learned.
1. Yes, they're progressive but a much improved spring rate that works better for street/track use over previous generations. I'm riding A group at Buttonwillow on stock fork springs, but with 20wt oil and pre-load adjusters. (I weigh 145lbs currently) 2. For those with an R3 (don't witch hunt me Ninjette's lol, I own both currently) swapping in the springs and spacers from the N400 to the R3 vastly improves it's handling. Highly recommend on a budget. 3. Despite my friends winning amateur class championship and me riding A group on stock springs, I'm still opting to get a full set of cartridge inserts for full damping control, that will also be sprung to my weight and riding ability. In short, TLDR, for 90% of Ninja / Z 400 Riders out there, even for the track, the stock springs will take you into racing just fine, but are still worth upgrading. |
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