[b0Xcrash]

Sounds about right to me. What kind of sag numbers are you seeing? I'm about 185 without gear (leathers, helmet etc...) and saw right at 20mm loaded with a cold shock and rebound & comp set in middle.

Ok, shame on me, I know that is the very first thing I should do, but I have not.
I only weigh about 150-155 without gear.
I do not have anyone to really help me.......but maybe its time my 14 year old son learns, he does good with most stuff, but this one, and my OCD I will need grace and patience if he does it any different than I would want. Lol I am not that hard to live with....I think.

I believe we can swap out springs ourselves. Just need to buy those spring compressor thingys on eBay.

I would think so, appears to just be a Showa 40mm shock


Yeah, I made my own fork compression tool like the Race Tech one(for tearing down the inverted forks), but even better in my opinion. I fabricated, measured and welded it all up myself and powder coated it.


I will have to look at the spring tool for shocks and maybe do the same thing

With back end 5mm up may need? to lower tubes in triples to raise the front end? My GSX-R has been raised on both ends with fork extenders & a Penske shock. I do agree with you that the back end feels much firmer & taller. Maybe not as much sag as compared to OEM? ?Did you state that the OEM GSX-R shock is height adjustable?

Edit - correction: With back up, stock up front might be good, but I left mine dropped 4.35mm up front.

I also drained the fluid out and added 15w or 20w fluid up front and an extra +20mm fluid. Also installed preload adjusters. I will need to check my documentation on this as well. I know this is "not" cartridges and springs, but its better than stock.

Edit- more I thought of: Something else to consider is if you remove the stock clipons, and mount clip-ons underneath the triples you have way more fork to work with, that would give us alot of extra room to raise the front end, and you can get clip ons with risers to move them up further mounted underneath top triple. But I think stock height or even dropped 5mm is all the room we need.

yep, its not an easy, twist this knob, adjustment like a K-Tech or Ohlins, but yes you can adjust the rear shock height on a GSX-R. The upper shock mount has a nut with some threads, I know you used to be able shim/washer stack those puppies some and get 3-6mm out of that raising up the back end some?

Can you still do that with these on the GSX-R 600/750???

My only concern now is that even with the K-Tech springs 80/85 in the forks the front end still needs better internals/carts to deal with the firmer shock. Im not ready to shell out $1k yet for Ohlins or K-Tech etc.... carts. I would probably chat with Matt Patton. My carts in my GSX-R are stock and are fine for my level (intermediate) at the track. He uses GSX-R carts in his retro fits.


We just need to get this shock in front of a suspension guy to see if the OEM springs etc... are not compatible.


I will prob be at Pocono in a week or so and then hopefully NJMP the following weekend. Pocono will prob have NO suspension guy but NJMP should but he runs the show (Mark-Markbilt). I have my clutch out now and I did replace the shift shaft oil seal. Barnett springs & the SPEARS bits n' bobs going in. That shift adj kit REALLY tightens up that shift shaft slop.

Right I rode mine today to work, roughly 52 miles, and it's way better for handling. It feels planted way more, more precise and re-active.

Is it stiff, and can I feel every bump and imperfection in the road? Uhh, yeah pretty much...a yes.
Do I like it? Yes
Will my neck and lower back like it? Pretty dang sure a resounding nope on that one.

But, I can tell a difference. It seems to drive harder out of the corners, more planted and less squat.
Feels to me more agile, and maybe its just my mind dealing with the stiffer shock.

Also I have a bad habit I formed many years ago of weaving back and forth in the lane, scrubbing tires in or preventing "table tops" down the middle of the tire wear on long straight rides, like interstates, highways.(talking 1993 when I started that and first started riding on the street, stories about riding with old guy veterans that said to do it, scrub the dust and oil/etc. off the tires urban myths, etc.)

I do this safely. I also know this does not heat up the tires any, as motorcycle tires do not behave the same way as car tires do and F1, GT, etc. so scrubbing to keep heat in them, back and forth motion would not.

But I can tell it no longer squats or squishes the back end feeling all loosey/goosey, noodley out back anymore. I mean it was not horrible before like the 05 Ninja 250 was, but I could definitely feel it.

Also I will know on the ride home for sure, but again drive through the corners feels better. The back end before on hard drives and hard accel felt like the tire was breaking loose or greasy sometimes before, which I do not think it was. Cause now more swingarm angle should make it break loose more than squat would, who knows, I will know for sure later.

I messed with all the setting, pre-load ( I thought the way it came was way too pre-loaded for my weight), low and high speed compression, rebound (lower mount I think is way off) cause I did it in a hurry in the driveway as I was leaving this morning and I get my adjustments mixed up sometimes. I thought clockwise was all the way in soft, and then you turn towards hard X amount of turns. But the darn embossed shows the direction arrows, as I read them the opposite, so not sure where it is right now, lol

I also would like to do carts up front, but not sure myself either on investing and since most have you cutting the fork tubes, not committed to that kind of tear down and work right now...sounds like a winter job for me.


I am anxious to hear what the suspension experts and race setup says/shows to see what we have.

 

[b0Xcrash]

On the ride home to me, almost night and day. I went out at lunch and messed with the rebound, and believe I got the adjustments right. It feels better, not as teeth chattering and more forgiving and smooth on the bumps.

It is way more responsive and feels better, feed back 10 times better, more planted feeling, much smoother and better drives. Maybe its placebo effect but it feels like an entirely new bike.
I am no Rossi, Hayden or Colin Edwards, but I feel faster with it and smoother. Reminds me of how the SV handled but not as twitchy and sensitive.

 

[Kiwi Rider]

On the ride home to me, almost night and day. I went out at lunch and messed with the rebound, and believe I got the adjustments right. It feels better, not as teeth chattering and more forgiving and smooth on the bumps.

It is way more responsive and feels better, feed back 10 times better, more planted feeling, much smoother and better drives. Maybe its placebo effect but it feels like an entirely new bike.
I am no Rossi, Hayden or Colin Edwards, but I feel faster with it and smoother. Reminds me of how the SV handled but not as twitchy and sensitive.

Good one, sounds like you've had a win then. You should still get your son to help you measure your bike and rider sag though. Not essential but then you will know your in the ball park. The main mistake people make is thinking that the unloaded figure is taken when the bike is on a rear stand. And keep fiddling with compression and rebound clickers until your completely happy.

 

[Scook2397]

….SO where did you end up with the adjustments? Comp & rebound. I haven't touched them yet.

 

[Kiwi Rider]

….SO where did you end up with the adjustments? Comp & rebound. I haven't touched them yet.

I had the GSXR 600/750 shock on my old GSXR400 race bike. Sorry for any confusion. I cant remember the settings now.
The K-tech shock I have on my Ninja 400 I am currently at -2 clicks on the recommended settings listed in the manual that came with the shock. But when the weather gets warmer I plan to get out and do some serious testing/evaluation. Completely different scenario for road set up but I like the fact that now if I do a track day I can tweak it to suit.

 

[b0Xcrash]

….SO where did you end up with the adjustments? Comp & rebound. I haven't touched them yet.

Compression damping: High-speed: 2.75 turns out; Low-speed: 1.75 turns out (I turned both all the way clockwise in, then came out or counter clockwise to the turns indicated)
Rebound damping, lower adjustment: 2.5 turns out, and turned it all the way soft and then came out 2.5 turns

6mm of thread showing up top, this is probably way low, but it felt good to me, I might move it down some and expose some more thread, seems it was at 10 probably before......but with sons help should get proper sag numbers

Edit - I also have 20mm sag, 20-22mm without gear.

 

[Scook2397]

HI All, Got 6 sessions in today at Pocono's North Course. Back end felt fine to me. I had preload backed off. I think I was getting 25mm sag with me on bike and no gear. I didn't fiddle with any adjustments. Just rode. I have current gen GSX-R 600/750 shock, SPEARS rear ride height adjust & K-Tech springs up front (.80 & .85) with preload adjusters lightest adjust. Could put the bike wherever I wanted and anybody who has ridden Pocono knows how bad the transitions from the infield to the banking is. Rode around a couple big bikes today so I was happy.

 

[Kiwi Rider]

HI All, Got 6 sessions in today at Pocono's North Course. Back end felt fine to me. I had preload backed off. I think I was getting 25mm sag with me on bike and no gear. I didn't fiddle with any adjustments. Just rode. I have current gen GSX-R 600/750 shock, SPEARS rear ride height adjust & K-Tech springs up front (.80 & .85) with preload adjusters lightest adjust. Could put the bike wherever I wanted and anybody who has ridden Pocono knows how bad the transitions from the infield to the banking is. Rode around a couple big bikes today so I was happy.

Nice one, sounds like you ended up with a good upgrade there. Beating the big boys is always pleasing. :biggrin:
25mm rider sag is a good average setting for the track.
It might be worth having a play with the clickers if you can be bothered/are interested. Just take a note of what they are set on now so you have a known baseline to revert back too.

 

[Slow Hand]

To those of you sharing your experiences and strategies with this shock swap THANK YOU! I learned so much from your discussion, and all of the detailed measurements were an enormous help.

I just installed what sounds like the same current gen GSXR shock as bOXcrash. (The eBay ad had the same inaccurate eye-to-eye distance of 13" that he mentioned.) It was a steal at only $25 and free shipping.

I'll share my settings below, but I just wanted to say to anybody considering this mod themselves, it is sooo worth it. I took my bike out for a test ride after installing the shock yesterday and was utterly blown away by the upgraded performance. I am lucky enough to live in an area with a lot of twisty roads, some of which aren't the smoothest -- which really challenged the OEM shock. Rebound damping, in particular, seemed to be a weakness of the stock shock, which would often lead to a feeling of suddenly being weightless and unplanted in corners. With the GSXR shock that feeling is gone. I found that I was carrying 5-10mph more speed through corners without even pushing it. The bike just feels so much more stuck to the asphalt that it naturally inspires more confidence. The one downside is that now I am suddenly aware of the limitations of the fork, which is thankfully not as bad as the shock was. I'm hoping there's a similar low cost/salvage strategy for upgrading those as well!

My setup:
GSXR 600/750 shock
* Measured 315mm (center-of-eye-to-center-of-eye)
* OEM shock measured 320mm (so that's a loss of 5mm)

Spears Racing Ride Height Adjusters
* flipped to the +10mm orientation (for a net gain of 5mm)

Swing Arm Angle
* OEM swing arm angle is 9.5°
* Net +5mm increase in shock length
* Increases swing arm angle to 10.3°
* Increases ride height by 10mm (according to Spears Racing)

Shock Settings
* Preload -- ~6mm of thread showing
* High Speed Compression 3 turns out
* Low Speed Compression 2 turns out
* Rebound 2.5 turns out

These were the settings on the shock when I received it. I haven't properly measured sag yet or made any changes to the settings but they felt pretty good with my 165-pound body weight as-is.

 

[Scook2397]

anybody come up with an economical fork upgrade option (s)? I do have K-Tech Springs and preload adjusters. I'm guessing oil weight and amt next cheap options. I just don't know enough (other then heavier weight) to know which way to go. ?Anybody have any good luck on this front?

 

[Scook2397]

just had interesting conversation with a K-Tech Tech: He said the OEM GSX-R shock has a lighter spring rate then the OEM N4 shock spring rate.

 

[b0Xcrash]

just had interesting conversation with a K-Tech Tech: He said the OEM GSX-R shock has a lighter spring rate then the OEM N4 shock spring rate.

What?!?! How is that even possible? Was he just trying to sell you that K-Tech?....

I am calling BS on that

Or is the OEM N400 shock such a push-up pop filled with mashed-potatoes(and gravy of course) that two pieces of plate steel bolted on either side of the shock would squish under any kind of weight and forces??!

I can tell a very noticeable difference between the N400 stock shock and the GSX-R shock...and the spring rate on the 600 shock is 10.1 kg/mm and the 750 is 10.5 kg/mm.

So are we saying the Ninja 400 OEM shock spring rate is 10.6 or higher?!?! Like a Busa shock, a 14.5 kg/mm or something?

Kiwi said earlier it was way lower, like 8.6 and his K-Tech is 8.15...maybe he means the K-Tech has a softer spring by default than stock?(cause you can always get whatever spring you want)

***Found it, the comparison of the Z400 and the N400, see image straight from Kawi:

"The rear shock spring rate was softened on the Z400 roughly 10 percent from 94 to 85 N/mm."

Which translates to 9.5 kg/mm on the N400, so the 600 is .6 kg/mm stiffer and the 750 is exactly 1 kg/mm stiffer.

I tried to find out how to tell the difference between a 600 or 750 shock, but RaceTech never responded...........

 

[Kiwi Rider]

... Kiwi said earlier it was way lower, like 8.6 and his K-Tech is 8.15...maybe he means the K-Tech has a softer spring by default than stock?(cause you can always get whatever spring you want)

***Found it, the comparison of the Z400 and the N400, see image straight from Kawi:

"The rear shock spring rate was softened on the Z400 roughly 10 percent from 94 to 85 N/mm."

Which translates to 9.5 kg/mm on the N400, so the 600 is .6 kg/mm stiffer and the 750 is exactly 1 kg/mm stiffer.

Ah thank you! It was annoying me that i couldnt find that info. My memory was obviously well off the mark with that figure.

OK so we now know the N400 shock is 94N/mm
The standard spring the K tech shock comes with is 95N/mm as most people buy them for race bikes, so it shows how stiff the OEM spring is. No wonder they changed it for the Z400.
I got my spring replaced by the K-Tech dealer free of charge for an 80N/mm jobbie which suits my 130lb weight nicely and gives me around 35mm of rider sag at the rear.

 

[Scook2397]

He said I maybe had to get a stiffer spring in the GSXR shock. No Joke. Maybe that N4 shock really is a POS. Like you guys said, now even with K-Tech springs up front (.80/.85) I think I at least gotta swap for heavier oil. I think KIWI is right on with his numbers. And the K-Tech Tech really didn't try to sell me anything. He talked me out of buying a lighter rate spring. Maybe N4 OEM over sprung with crappy damping etc... If you are pulling OEM numbers from Race Tech, some on here have said their numbers can be off. But I'm not expert. SO.....we just gotta find someone who can do a cheap GSXR cart swap...I'm not sure if Matt Patton does them anymore. Zoran is almost as $ as Ohlins.

 

[b0Xcrash]

He said I maybe had to get a stiffer spring in the GSXR shock. No Joke. Maybe that N4 shock really is a POS. Like you guys said, now even with K-Tech springs up front (.80/.85) I think I at least gotta swap for heavier oil. I think KIWI is right on with his numbers. And the K-Tech Tech really didn't try to sell me anything. He talked me out of buying a lighter rate spring. Maybe N4 OEM over sprung with crappy damping etc... If you are pulling OEM numbers from Race Tech, some on here have said their numbers can be off. But I'm not expert. SO.....we just gotta find someone who can do a cheap GSXR cart swap...I'm not sure if Matt Patton does them anymore. Zoran is almost as $ as Ohlins.

Ahh ok I gotcha, yeah I show elsewhere the GSXR-1000 09-12 (11.6 kg STK) and Racetech also shows 11.6, maybe they got the 600 and 750 right? lol :grin:

Yeah depending on your weight I would probably say the stock GSX-R spring might be under sprung for you

 

[yarddog]

definitely on the to-do list. i swapped a GSXR shock on my old 250, coupled with race-tech front springs and the difference was amazing.

 

[b0Xcrash]

definitely on the to-do list. i swapped a GSXR shock on my old 250, coupled with race-tech front springs and the difference was amazing.

Yeah without dropping $400-1000 on an aftermarket shock you can get night and day with a GSX-R shock.
I mean if you are at the top of the pack podium stuff and need that extra edge, sure I would go with an Ohlins or higher end K-Tech, etc.
I have done GSX-R swaps on other bikes as well, they always seem to be the best shock for the job with plenty of adjustments over stock, well except the KTM RC 390 using R6 shocks instead, at least when they first came out and I was into them

Was pretty easy, and you can take the stock shock mount plates off, swap them left to right and turn them upside down to gain back any loss in eye to eye length(look at my numbers to see the loss and then the gains in ride height) and keep the mounting tabs for the airbox on them.
I cut mine off and powder coated them because how the tray and can be reinforced supported and where it rests on the shock mounts, engine top and etc. not necessary, especially if you move the tool bag to your external storage or remove it.

 

[thegenius46m]

Anyone have part numbers for this setup? Is the rear plug and play or is a spring swap necessary?

 

[Scook2397]

I bought a current generation 11+ Gsxr 600/750 shock off ebay. I believe I used 2@M10 washers for the bottom mount. Some ppl flip the upper shock mounts. I used Spears ride height adjusters. I weigh around 185 but with all my gear (leathers etc..) K-Tech rep stated no spring needed. If you are lightweight or short then maybe rethink spring or upper shock mount if you need to lower bike. I track my bike only.

 

[Kiwi Rider]

Anyone have part numbers for this setup? Is the rear plug and play or is a spring swap necessary?

Spring swap is dependent on individual rider weight and intended use. Rough guide: For road use you want the rear to sag 30 - 40mm when you sit on the bike and about an inch for track use. The first or base measurement needs to be taken with the suspension fully unloaded though so get a friend to pull the bike over on the side stand for you.