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Discussion Starter #1
Well I finally got around to the shock swap. Been battling kidney stones for the last month plus. ughh… I swapped out the stock shock with a current Gen GSX-R 600/750 shock. Was actually a lot easier then I thought. Got the bike up on the frame stand. Took some measurements first. Took off rear wheel. Got the impact driver out and removed the stock shock. Both the stock and the GSXR shock run M10 bolts upper & lower and I used the stock bolts. One bolt is longer then the other so mark them. Fitted the new GSXR shock in. Upper mount is dead on. NO fenagling. Lower mount just needs 2 M10 washers to take up some slop. The GSXR shock is narrower on the lower mount the stock shock. Looks like plenty of clearance. GSXR spring is wider but seems to clear all+. First blush lowered back end by 5/8 ". Will check twice. I bought the SPEARS ride height plates so they will go on when I figure out how much I truly lost (5/8"?). Or make adjustable dogbones out of rose joints and threaded rod. Or Soupy's makes adjustable ride height dogbones. There is usually a guy who can help tune the suspension at track days for ca$ Im hoping with my at 215lbs. plus with all gear (leathers etc...) the spring wont be too hard. Pre-load at softest.


I have the fork pre-load adjusters. I figure ''m at least 215lbs with leathers etc... on. Got to get fork springs.
?what springs do you all recommend?
 

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Interesting swap, cheaper option than an aftermarket one designed for a N400 but your limited by the eye centre distance as you found out.
I put this same shock in my old GSXR400 race bike and it slotted in perfectly, length was correct too.
Because your 100kg odd you will probably get way with it but if it's too stiff then change your spring rather than backing your preload right off as then your ride height will be even lower than it is now and the shock will not be operating in the sweet part of its stroke.
Let us know how you get on.
 

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Discussion Starter #5
Installed the SPEARS rear height adjusters. Not too hard but gas tank needs to come off plus move a couple things under the gas tank. Still came up 5/8" short from stock with the GSXR shock so went with the lower mount points with the plates which came out about 3/8" taller then stock. Still have not checked sag.


You guys are correct, getting the rear rim back on is a PIA. I hope Fast by Frank makes a rear caliper mount for the N4.
 

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Discussion Starter #7 (Edited)
Will be at NJMP Lightning this Sunday for my first day on the N4. Hopefully Mark from MarkBilt will be there to help adjust what can be adjusted. Current gen GSX-R 6/7 shock out back with SPEARS ride height adjuster & K-Tech springs up front with pre-load adjusters.... and brand new Q3+'s...
 

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Will be at NJMP Lightning this Sunday for my first day on the N4. Hopefully Mark from MarkBilt will be there to help adjust what can be adjusted. Current gen GSX-R 6/7 shock out back with SPEARS ride height adjuster & K-Tech springs up front with pre-load adjusters.... and brand new Q3+'s...
What rate springs in the GSXR shock? It's a lot heavier bike so could be a bit stiff perhaps.
 

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Discussion Starter #9
yeah probably on a lark with the GSXR shock but at least cheap!i... but check out the Frando radial caliper adapter dry fitted...piece to axle not connected...may need 1mm spacer for the caliper...still running the OEM caliper this weekends track day...
 

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Discussion Starter #10 (Edited)
First blush rear 20mm loaded sag without my gear. I have not touched the shock other then Comp & Rebound in middle adj. Did not touch pre-load. Shorts t-shirt sneakers only. No Helmet, leather etc... I figure that's another 20lbs plus. We will see tomorrow when the suspension guy takes a looksy at it.


Pre-load adjuster & K-Tech springs fitted with adjustments made on the spacers for both. OEM oil & amt.
 

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First blush rear 20mm loaded sag without my gear. I have not touched the shock other then Comp & Rebound in middle adj. Did not touch pre-load. Shorts t-shirt sneakers only. No Helmet, leather etc... I figure that's another 20lbs plus. We will see tomorrow when the suspension guy takes a looksy at it.


Pre-load adjuster & K-Tech springs fitted with adjustments made on the spacers for both. OEM oil & amt.
Was the 20mm difference taken from a true unloaded reading with the swing arm fully unloaded (ie. not on a rear stand) or was it with the weight of the bike on the rear wheel?

If its a true unloaded - rider sag difference then yes, it's too little. But if the 20mm is the difference between bike sag - rider sag then it's about right.

If it's the former then you need to back off the pre-load adjuster rings until you get an unloaded - bike sag difference of 10 - 15mm depending on whether its for track or road. Then check your rider sag again where you will be looking for 25 - 35mm depending on your intended use.
If you cant get the rider sag figure correct by using the pre-load adjuster then your spring is too stiff, simple as that. :)
 

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correct...both

So this is a K6/7 shock off the GSXR?
It was 5/8 shorter? So 15.87mm shorter?


I was born and raised in the USA and love the USA, but I prefer millimeters for all my measurements, especially on bikes because I can get so much more precise with simple numbers, versus fractions



I ran a GSXR 1000 shock on the SV, was the best way to go affordable and get all adjustments out of, well except high speed...cause it was a K5/6 I think as that one was the same length(I would have to check my excel spread sheet of measurements)
 

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Nevermind, looked at my chart, shows the GSXR 600/750 rear shock K6-K10 is 315mm, I want to say the Ninja 400 rear shock is 320 eye to eye........
 

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Discussion Starter #16 (Edited)
I own a 2006 GSX-R 750. The shock on my N4 is from a current gen GSX-R 600/750. 2010+ I'm guessing. The shock from my 750 would not fit on the N4 due the attachment points. I have a stock 2006 GSX-R shock in my arage. I believe the upper mount on the OEM is a bolt, not eyelet. I believe my original post stated with the GSX-R shock in the N4 the bike sat approx. 3/8" lower but I may be incorrect. Not sure how many mm.
 

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I own a 2006 GSX-R 750. The shock on my N4 is from a current gen GSX-R 600/750. 2010+ I'm guessing. The shock from my 750 would not fit on the N4 due the attachment points. I have a stock 2006 GSX-R shock in my arage. I believe the upper mount on the OEM is a bolt, not eyelet. I believe my original post stated with the GSX-R shock in the N4 the bike sat approx. 3/8" lower but I may be incorrect. Not sure how many mm.
Ok, thanks, gathering info, info junkie to find cheaper, superior alternative, options out there with anything.

That makes more sense as I had a K6 GSXR 1000 shock laying around and yes, both the upper was different mounting methods, and lower was also pretty far off, if I remember right, it used a bolt instead of eyelet/bushing open mount.

The 2011-19 GSXR 750 shock is 319mm, or at least according to what Ohlins shows, with a 65mm stroke.
Ninja 400 Ohlins is 320 eye to eye.

3/8 would be 9.5 mm converted. All interesting info, and with the spears mounts we can go up 5 and 10 mm, of course changing the swingarm angle
 

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So the rear GSXR shock has to be 2010 or newer. I will check around for one. How did the rear feel on Lightning? Was a suspension guru there to dial it in? A few of the guys at NYST we’re talking about this set up. They have 400s and they are gonna go with the GSXR rear shock. What are your thoughts on the rear now?
 

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So the rear GSXR shock has to be 2010 or newer. I will check around for one. How did the rear feel on Lightning? Was a suspension guru there to dial it in? A few of the guys at NYST we’re talking about this set up. They have 400s and they are gonna go with the GSXR rear shock. What are your thoughts on the rear now?
Looks like it needs to be a 11- on up from what I can tell, so 2011 - 2019 rear shock
 

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Check out E-bidding websites, I’m being pretty specific on that. Just got out of warranty in May and have a small trail of possible fluid leaking from my rear shock, so I may pull the trigger on the purchase of one. Would adjustment be needed since the gsxr and N400 are very different in weight alone not considering my weight and the weight of gear and backpack with tons of books for schooling.
 
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