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While we wait for more information to come out along with first ride reviews, here I have included some specs on the brakes and suspension. Kawasaki intended to make this a more aggressive entry-level street/track bike (in case the CC's didn't give it away :grin:) and so with that comes a level of control that should reflect the performance we're dealing with. This will be my first sport bike so getting feedback from experienced riders is what i'm after here.

Feel free to add any information that might be helpful.

  • Brakes, front Single semi-floating 310 mm petal discs. Caliper: Single balanced actuation dual piston
  • Brakes, rear Single 220 mm petal disc. Caliper: Dual-piston
  • Suspension, front 41mm telescopic fork
  • Suspension, rear Bottom-Link Uni-Trak, gas-charged shock with adjustable preload
 

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I'm really interested in this side of the bike as well. I guess you could call me an experienced rider (30 yrs riding) and I've gotten into sealed circuit racing as well so I've had to learn a bit about suspension in recent years.

One of the biggest let downs with these 300/400cc bikes is the standard suspension. Can't be too hard on the manufactures though as these bikes are built to price point. If you want fully adjustable USD forks then you need to fork out the big bucks for a 600cc super sports.
The main complaint is too softer springs and a lack of damping. This set up provides a nice plush ride for general commuting etc but not so good for the sports riders. The front end dives under heavy braking and on uneven surfaces you get wallowing, pogo-ing and even bottoming out at times when your really pushing it through the bends. You can upgrade the springs with stiffer aftermarket ones and fit emulator valves inside the forks which provide some compression damping adjustment but its all $$$

The good news is I read in the MCN release info on this bike that quote: The stiffer, non-adjustable 41mm (previously 37mm) fork had been developed to deliver better action.
So the larger fork diameter will give better rigidity and the stiffer springs will help keep the action under control more when sports riding.
So the front end sounds promising :grin:

The rear shock performance of the Ninja 650 released last year was rated as pretty average by a few testers so lets hope that's not the case with the 400. There's not so much you can do with these budget rear shocks as they are a sealed unit. There will be the usual spring pre load adjustment on this bike but no provision for compression and rebound damping which is really important for a good set up.
Just have to take it as it comes and make a decision then on whether to upgrade to aftermarket or not. I'm sure it will be fine for 90% of riders though.
 

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I'm really interested in this side of the bike as well. I guess you could call me an experienced rider (30 yrs riding) and I've gotten into sealed circuit racing as well so I've had to learn a bit about suspension in recent years.

One of the biggest let downs with these 300/400cc bikes is the standard suspension. Can't be too hard on the manufactures though as these bikes are built to price point. If you want fully adjustable USD forks then you need to fork out the big bucks for a 600cc super sports.
The main complaint is too softer springs and a lack of damping. This set up provides a nice plush ride for general commuting etc but not so good for the sports riders. The front end dives under heavy braking and on uneven surfaces you get wallowing, pogo-ing and even bottoming out at times when your really pushing it through the bends. You can upgrade the springs with stiffer aftermarket ones and fit emulator valves inside the forks which provide some compression damping adjustment but its all $$$

The good news is I read in the MCN release info on this bike that quote: The stiffer, non-adjustable 41mm (previously 37mm) fork had been developed to deliver better action.
So the larger fork diameter will give better rigidity and the stiffer springs will help keep the action under control more sports riding.
So the front end sounds promising :grin:

The rear shock performance of the Ninja 650 released last year was rated as pretty average by a few testers so lets hope that's not the case with the 400. There's not so much you can do with these budget rear shocks as they are a sealed unit. There will be the usual spring pre load adjustment on this bike but no provision for compression and rebound damping which is really important for a good set up.
Just have to take it as it comes and make a decision then on whether to upgrade to aftermarket or not. I'm sure it will be fine for 90% of riders though.
I concur. Even for normal track days, the stock tyres and suspensions will be adequte for 90% of owners. And the good news is that there will be Ohlin fork up grades ( two kits), plus new rear shock absorber, fully adjustable, specifically for the NinJa 400. Pirelli Diablo Supercorsa SC2 tyres are available for those who require extreme tarmac adhesion.:D
 

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I concur. Even for normal track days, the stock tyres and suspensions will be adequte for 90% of owners. And the good news is that there will be Ohlin fork up grades ( two kits), plus new rear shock absorber, fully adjustable, specifically for the NinJa 400. Pirelli Diablo Supercorsa SC2 tyres are available for those who require extreme tarmac adhesion.:D
How did you find the standard tyres during your track test? Any slides? I cant actually remember what brand the standard tyres are.
One benefit you have in Thailand over where I live is your track temperature and subsequent high level of grip. We often race in an ambient temperature of 10 - 15 degrees C so despite tyre warmers, grip (or rather a lack of) is a real issue. Got to get a few hard laps up and some heat into the tyres before you can really push.
 

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The good news is I read in the MCN release info on this bike that quote: The stiffer, non-adjustable 41mm (previously 37mm) fork had been developed to deliver better action.
I can't remember ever riding a bike with a 41mm front fork, maybe 40mm, even the '81 gold wing had 39mm forks. This will be a first for me.
I hope they have them setup well or we can collectively gain the best combination of setup from input from other owners of similar body weight and ambient conditions (*temperature does have a great effect on viscosity of fork oil).
 

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I can't remember ever riding a bike with a 41mm front fork, maybe 40mm, even the '81 gold wing had 39mm forks. This will be a first for me.
I hope they have them setup well or we can collectively gain the best combination of setup from input from other owners of similar body weight and ambient conditions (*temperature does have a great effect on viscosity of fork oil).
Unfortunately we will be limited to changing fork oil viscosity as these forks are non adjustable. This is how they keep costs down. You can swap out the springs for the likes of Racetech which offer a range of spring rates for around $150 USD. Ohlins offer a complete set of adjustable internals for the Ninja 300 but your talking $800. The Ninja 400 products showing on the Ohlins site are for the old Ninja 400 that was a sleeved down 650 from 2010 onwards.

But hopefully we dont need to go down that line, i'm sure it will be fine for street purposes. :)
 

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give it time

With the demand I am seeing for this bike, I would imagine there will be more aftermarket products after; the bike's delivery and their sales have escalated in numbers.
Supply and demand.
There doesn't seem to be a great supply of the bike in the US or foreign markets at this time (with the exception of Thailand where it is manufactured). Give it time, as a 400cc bike with the detailed engineering I am seeing (unless they have some hidden mishap with design) and keep the pricing of a 300cc, should create a great supply of owners and demand for aftermarket parts.
 

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How did you find the standard tyres during your track test? Any slides? I cant actually remember what brand the standard tyres are.
One benefit you have in Thailand over where I live is your track temperature and subsequent high level of grip. We often race in an ambient temperature of 10 - 15 degrees C so despite tyre warmers, grip (or rather a lack of) is a real issue. Got to get a few hard laps up and some heat into the tyres before you can really push.
Normally we have high track temperature >25 degree C in Thailand. But on track day, it was a little bit cooler. I guess around 22 degree C. I was the third person on the bike, and tyres were already warmed up. Stock tyres shod were Dunlop, but I cannot recall the model. I did not turn hard enough to really test the tyres, lots of traffic. But I took enough laps, and can assure you that stock tyres gripped better than average stock tyres that come with engine of this class. Nevertheless, I'm replacing them with Diablo SuperCorsa SC.
 

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I'm really interested in this side of the bike as well. I guess you could call me an experienced rider (30 yrs riding) and I've gotten into sealed circuit racing as well so I've had to learn a bit about suspension in recent years.

One of the biggest let downs with these 300/400cc bikes is the standard suspension. Can't be too hard on the manufactures though as these bikes are built to price point. If you want fully adjustable USD forks then you need to fork out the big bucks for a 600cc super sports.
The main complaint is too softer springs and a lack of damping. This set up provides a nice plush ride for general commuting etc but not so good for the sports riders. The front end dives under heavy braking and on uneven surfaces you get wallowing, pogo-ing and even bottoming out at times when your really pushing it through the bends. You can upgrade the springs with stiffer aftermarket ones and fit emulator valves inside the forks which provide some compression damping adjustment but its all $$$

The good news is I read in the MCN release info on this bike that quote: The stiffer, non-adjustable 41mm (previously 37mm) fork had been developed to deliver better action.
So the larger fork diameter will give better rigidity and the stiffer springs will help keep the action under control more when sports riding.
So the front end sounds promising :grin:

The rear shock performance of the Ninja 650 released last year was rated as pretty average by a few testers so lets hope that's not the case with the 400. There's not so much you can do with these budget rear shocks as they are a sealed unit. There will be the usual spring pre load adjustment on this bike but no provision for compression and rebound damping which is really important for a good set up.
Just have to take it as it comes and make a decision then on whether to upgrade to aftermarket or not. I'm sure it will be fine for 90% of riders though.
The rear suspension is horrible on concrete pavement.. you will end up having slip disc on your vertebrates.
 

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The rear suspension is horrible on concrete pavement.. you will end up having slip disc on your vertebrates.
Lol! C'mon it's not quite that bad. :smile_big:
My CBR 300 had a worse rear shock, I nearly tied that thing in knots a couple of times when I pushed it too hard. :D

I'm thinking a Nitron or such like would probably do the job as far as an upgrade goes, a bit cheaper than an Ohlins etc.
 

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With the demand I am seeing for this bike, I would imagine there will be more aftermarket products after; the bike's delivery and their sales have escalated in numbers.
Supply and demand.
There doesn't seem to be a great supply of the bike in the US or foreign markets at this time (with the exception of Thailand where it is manufactured). Give it time, as a 400cc bike with the detailed engineering I am seeing (unless they have some hidden mishap with design) and keep the pricing of a 300cc, should create a great supply of owners and demand for aftermarket parts.
I had read somewhere that the N4 is manufactured by Kawasaki in Japan...Do we know for sure that it is built in Thailand?
 

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According to my VIN:

Plant Country: Thailand
Plant Company: Kawaski Motors Enterprise Co., LTD
Plant City: Amphur Pluak Daeng
Plant State: Rayong
 
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Some little information about fork setup
- do not fall on the superstition about too stiff springs, please read Peter Verdone Designs - Motorcycle Springs and last page from Ohlins manual https://www.ohlins.com/app/uploads/world/2018/02/MI_FKS224_0.pdf
- also do not fall on the same about too heavy oil weight, in the forums there is too many talk about 15W.
10W fork-oil is more than enough, I think about change to 7.5W the next time and please take note that I live in a very hot environment.
With 15W fork-oil the rebound nearly doesn't exist no more. Better play with the air gap.
If you have any chance to buy this product HKS-Czech - Kettenpflege vom Spezialisten then get it because you'll never regret.
Description: "The use of HKS GGV completely eliminates the so-called telescopic fork breakaway torque. Even the smallest unevenness and the like are no longer transferred from the unsprung part of the telescopic fork to the motorcycle. The result: silky-smooth, smooth handling and the safest ground contact. A noticeable benefit! The interaction with an HKS extremely lubricated chain results in a "butter-soft ride"! A breakaway torque no longer exists!"

Good luck.
 

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Don't "guess" at oil viscosity - the 'W' notation on the bottle is worthless. For damper rod forks you're probably going to be around a [email protected] oil depending on the particulars of the damper rod itself and the ambient temperature.

If you want proper suspension behavior you're going to have to pay. At least since it's finally now a 41mm system the kits should come fast and furious:
  • Matris F15k
  • Ohlins NIX-22
  • Andreani
  • K-Tech IDS20.
I'll probably look at doing my GSXR/Showa fully-adjustable cartridge retrofit at some point. Depending how long it takes the factories to get product designed, I/others can probably modify an existing Andreani/NIX/Matris (eg. FZ07, R3, SV650) to suit.

Seems Ohlins is still specifying fork springs that are WAY too soft. Are they jacking the preload something fierce? I had some springs custom wound for me for use with the Matris cartridge for the Ninja300. 100kg (220lb) rider on 0.75kg/mm? No freaking way!

The nearly universal problem with these aftermarket fork products is that they are valved too stiff on compression. On smooth tracks, it's not a problem. But real-world roads have all kinds of irregularities and as delivered can't flow enough oil, fast enough to accommodate 150-200+ in/sec of movement. Sometimes you can band-aid with a really thin oil. But the real fix is to flip the piston over and re-shim.

Sonic has (or will) springs for a lot less than RaceTech.
 

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According to my VIN:

Plant Country: Thailand
Plant Company: Kawaski Motors Enterprise Co., LTD
Plant City: Amphur Pluak Daeng
Plant State: Rayong
Ouch, How did you get a Thai bike all the way over in the US. The first digit in my VIN is "J" indicating my N4 purchased in Chiang Rai Thailand is from Japan. JK=Japan Kawasaki if i read that right. All the other local bikes (in our driveway) have VIN numbers ML (Thailand) and MK (Indonesia)

Just to keep on topic; I must be in the other 10% of riders as I am not getting that warm fuzzy felling with the stock suspension. I'm beginning to think the bike marketed in Asia have suspension setup for the lighter riders. At 72 Kg just about everything I've ridden here is setup really soft. (or I'm just old and particular about my ride)
Anyone know the similarities & difference between the N650 and N400 forks, other than having 41mm.
A little more research is needed before running to the suspension shop. Aftermarket availability seems limited to Ohlins and K-Tech, as far as i can tell.
 

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I must be in the other 10% of riders as I am not getting that warm fuzzy felling with the stock suspension.
I find the front OK as I'm only 130lb rider weight but the rear end leaves me cold. The action is harsh IMO.
I'm going to get a friend to give me a hand to measure my sags tomorrow. Just as a matter of interest.
I've got an $800 tuning bill coming up but after that I will think about rear suspension improvements.
 

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With 33mm static sag in the forks, I've decided to add some preload load and see what happens.

The old school street bike thing was to add preload with a longer spacer tube over the springs. Started with tubes cut to +20mm, not going happen, cut the tubes to, +11mm. That left 10mm static sag, the ride was great on smooth roads and track but stiff for day-to day riding. Then I found some Sniper fork caps with preload adjustment at Kawasaki TH.
I reinstalled the original tubes and installed the adjustable fork caps with 5mm preload. That seems to be ok compromise for now. Static sag sits at 20mm. The fork caps have preload adjustment of +3mm to +10mm.

Agree, the pogo shock will be another story for anther day.

Correction from previous post, choices I've seen are Ohlins TH and YSS. The off road guys are using K100 out of China.
(K100, K-TECH & K TECH technical school, confusing for old people)
 

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With 33mm static sag in the forks, I've decided to add some preload load and see what happens.

The old school street bike thing was to add preload with a longer spacer tube over the springs. Started with tubes cut to +20mm, not going happen, cut the tubes to, +11mm. That left 10mm static sag, the ride was great on smooth roads and track but stiff for day-to day riding. Then I found some Sniper fork caps with preload adjustment at Kawasaki TH.
I reinstalled the original tubes and installed the adjustable fork caps with 5mm preload. That seems to be ok compromise for now. Static sag sits at 20mm. The fork caps have preload adjustment of +3mm to +10mm.

Agree, the pogo shock will be another story for anther day.

Correction from previous post, choices I've seen are Ohlins TH and YSS. The off road guys are using K100 out of China.
(K100, K-TECH & K TECH technical school, confusing for old people)
When you say static sag did you mean rider sag with you on the bike as well?
Static sag is taken with the weight of the bike only on the suspension.

I never reported back but I got 8mm static and 33mm rider sag when I measured it up. The rider sag figure is about right but the static figure is too little ideally. If any thing I would be cutting down the spacer tubes to lessen the preload and hence the amount of static sag.
The problem then is you can end up with too much rider sag
esp if you are a heavier rider so ultimately the only answer is stiffer spring rate.
These springs are about right for my light 130lb weight, I could easily back off the preload a bit and get away with it.
 
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