I found one thread stating that the spring rate for the R6 shock was 561lbs. Does anyone else have any information? It would be interesting to compare specs on these. I really wish that I had the benefit of a running bike with a good stock rear shock so that I could do some real world testing. If the spring is so soft and the geometry is very far off, I can see where this might not be a good upgrade but as for fit, this shock is a straight bolt in application. I also checked for clearances and there is more than 3/8" between the spring and the other components. With the swing arm fully extended, the bottom clevice doesn't seem to bind either. There is also  more than 5mm of clearance for the spring to pivot at the top mount so if the geometry of the bike allows the shock to "swing" outward toward the rear wheel, there is room.


EDIT: I found dgyver's spring rate chart in another thread here http://gstwins.com/gsboard/index.php?topic=34112.0
EDIT EDIT: Here is the link to the customfighters sticky on shock swap info. http://www.customfighters.com/forums/showthread.php?t=12827
EDIT EDIT EDIT: I finally found a blurb on an R6 spring rate here. (Take it with a grain of salt. Not sure how accurate some of this information is.) http://www.gixxer.com/forums/showthread.php?p=3499480

As for converting the measurements in the last post, I am coming up with 548 lbs / Inch using the 9.8 kg /mm. Can someone else with better math confirm this?

It would be really great if there were someone with a GS close by that would be willing to do this test. I would help install it and take measurements and such. (Pensacola, FL / Biloxi, MS?)

CB

Quote from: cboling on July 12, 2009, 07:03:38 AM
I found one thread stating that the spring rate for the R6 shock was 561lbs.

You could also try using this http://guzzitech.com/springrate.html.

Thanks. If I can dig out my old shock from the trash dumpster, I will get those measurements.

EDIT: I dug out the old shock. (Thanks goodness I don't have a lot of neighbors with babies.!!! Peeeeeeeewwww!!) I measured the spring coil=.39", the diameter (outside to outside)=2.83", and I am counting 4 free coils. (Not sure that is correct and not sure how far off my approx. measurements are going to affect the calculation) but using that weblink, I came up with 375 lbs / inch.

Buddha - how much do you think that the travel can affect the "stiffness" of the shock? If this calculation is close and if the R6 spring is rated near 500+ / inch, would differences in travel still affect the spring "stiffness" even though the spring rate is going to be that much higher?

See, you've confused him, because he's only used to swapping parts.  


If you can find the weight of the donor bike, minus swingarm/tire assembly, length of the swingarm and the linkages (center of bolt holes) (and the same for a GS), just plug it into Newtonian two-dimensional vector physics for torque.  
Comparative spring rate, based on GS linkages, isn't gonna prove very much.  The shock could be valved differently, the spring might be progressive ( ).   Unless you find the vector sums of everything involved, you're not gonna know until you ride it.  

If it turns out to be too soft, then you can play around with Buddha's "leverage" (aka, torque) by changing linkage lengths.  Based on the same math I just talked about, but only using GS measurements.  

That's actually the best way, if you have enough room to add the proper linkage:  
Find a better shock with full functionality, then alter the lnkage until it provides the proper support.  IF you've got enough under-body room to clear said linkage.  Of course, if the linkage-swingarm triangulation is reversed, you'd be shortening (not lengthening), and therefore you wouldn't need to worry about clearance.  




If you can find the force needed to compress the shock and spring, I'll talk you through it.  Sounds hard, but it's easy as pie.  Basic algebra.  




You're getting into actual design, not just swapping parts.  
Good job, in my opinion.  
But, I don't have a junk business that you're threatening. 

Just noticed that you've already got the force output of the shock!  See, you're so close to an answer!

Just measure the length of the linkages (centered in the middle of the bolt holes), the shock itself, the swingarm (to the center of the hub), the distance from the hub to the center of the tire/ground contact patch, and all their angles (in relation to one another).  Plug that into the torque equation along with the shock force output, it'll tell you how well you'll support the front portion of the bike.
Plug in the force output of the stock shock, and it'll give you a comparative. 
That way, you've got no need to find the COG, etc. 


Draw it up in a picture, and I'll even do the math for you. 

Once you have numbers on it, you can adjust the linkage to better apply the force output.  What would you rather do: add a centimeter to the linkage (using a great shock) ... or buy whatever the local junk dealer peddles you? 

Oh yea, the local junkyards and others dont have any R6 shocks ... period, cos R6's never break or crash ... ever.

Considering I have cleaned out the kat shocks and near about any GSXR shocks in the near abouts of my area ... r6 shocks will be a new item I can find and sell.
So the "local junk dealer" wants to peddle R6 shocks.

Yea, he will design the shock for you cboling. After that you can buy the right shock at the great magic shock store in the sky.

He just needs you to find the weight of the swingarm, wheel, disk etc etc of the R6 and the same for a GS. So yea there you go, that is all you need dude ... Easy.

Cool.
Buddha.

Did I mention it fits really nice?....................

Oh no ... you need to alter the linkage length as wlaziu says.

Sorry man, you cannot be just swapping parts, you need to design it, you need this much damping which means this is the oil viscosity ... my there is a big word right thar ... and you need to squeeze it through this size orifice ... dayyyum ... more big words ... did I even spell that right ... yea like that.

So please provide all the numbers he's asking and 2 decimal places is plenty and he'll design it ... after which you can just have it built for your perfect shock.

You cannot be swapping shocks, and neither can you make bearings seated with some ranrom tools. That also should be designed.

The old, fits in there, ride it down the block ... if it holds up, ride it across town, if that works and is better ... use it ... that really should not be allowed. Its just so primitive and you're playing into the parts peddler's business.

Cool.
Buddha.

Quote from: The Buddha on July 13, 2009, 01:10:12 PM
The old, fits in there, ride it down the block ... if it holds up, ride it across town, if that works and is better Cool.

So, why do you keep busting his balls before he has a chance to ride it? 

Cut the guy some slack, Fred Sanford.  Give him a chance to ride it first, before you throw in your valuable opinion on whether it's too soft. 
He's trying to help us, just like you with your carb business. 
You don't like when people find fault with your practices, do you? 


Now, if you don't mind, I'm trying to help the guy in the only way I can.  No need for a threadjacking flame-war. 

The weights aren't very necessary.  Just the lengths.  
(yeah, it'd be the most precise- using circular acceleration, but this will get you in the ballpark.)
It'll take 20 minutes with a good ruler to find the measurements, and whatever time it takes you with a protractor to find the angles.  
It'd take maybe 10 minutes to draw it in MSPaint, since I'm not familiar with the linkage assembly.  Or, just take a picture of it.  

Give me 15-30 minutes, IF THAT, and I'll tell you whether it'll be too soft.  


I'd measure it myself, but frankly, it's not my project.
And, I'm in the middle of making mufflers for you guys.  











I've already helped another guy on here with basically the same thing. 
http://gstwins.com/gsboard/index.php?topic=47418.0
Funny, you didn't seem interested then, Mr. Salesman. 

Maybe we are complicating this a little too much. I think the important part of what I was hoping for is that:
1. There was an alternative shock that would fit by simply bolting it on. (Mainly because there are simply no aftermarket parts for this bike despite it's world wide popularity.)
2. It would be completely adjustable as far as ride is concerned.
3. It is relatively cheap and easy to find at the moment.
4. It doesn't require any special skills to install. (Literally a bolt in application. I live in an apartment and with Harbor Freight sockets and wrenches, I was done in 10 minutes.)
5. It doesn't raise the bike or lower the bike that I can tell. The side stand and center stand still work exactly as before with no noticeable extra height or lean.

I know this may be a "softer" spring. It feels a little soft when I sit on it. BUT, I am a pretty big guy and the shock is also set at a low range. (Somewhere in the area of 4 and I believe there are quite a few more steps that the adjustment can be moved. I just need a tool!) I also realize that the geometry of the bike could cause the difference in the "softness" or "stiffness" of the spring. (huhuhuh, he said stiffness.)

But all in all, if it works out to be a comfortable ride and a safe ride with the new shock, the we all win, right?

As far as the discussion of measurements and geometry of the bike's linkages, I think it would be good information to gather for the Wiki eventually but for now, it really does come down to ride and try. The sad part is, I can't ride mine just yet. I keep telling myself, "Just a few more days....." Hopefully, someone else liked the idea enough to get one ordered and can try it out for us and let us know the seat of the pants outcome.

Wladziu: You're making mufflers? For bikes? Where can I get more info?

I don know sheite about suspensions (or I wont be bothered to technically dissect them) ...
Visual inspection, then fit and check, then ride round the block, then across town. Tht is my analysis.

Anything more is too complicated ... you know being a simpleton and all.

Cool.
Buddha.

that coil looks just like the gs coil. a katana shock is a direct bolt for me and mine is set to either 1 or 2 and i have about 2-3 of travel.

Damn, who cares if it is not the "ideal" shock.  He tried it, likes it, and will run it.  When he does and finds out if it is right, we will know. 

Quote from: O.C.D. on July 13, 2009, 07:54:50 PM
Damn, who cares if it is not the "ideal" shock.  He tried it, likes it, and will run it.  When he does and finds out if it is right, we will know.  

Exactly!  

The ever so popular Kat shock is complete crap and this board is due for an alternative swap.  

As Big shot said a few months ago (where is that guy, I miss his comments) QUIT DRINKING THE KOOL-AID.  Horay, a Kat shock is stiff...and cheap.  That's it.  It has nothing else going for it.   It's a cheap shock off of a low budget obsolete sportbike.  Compression and rebound dampening are a complete mess.  It's non-servicable.  It probably costs suzuki $10 to make it.  People need to quit raving about how great it is, because it's not.

Let the guy try.  Lets see how it works.  

Quote from: ineedanap on July 13, 2009, 08:39:50 PM
Let the guy try.  Lets see how it works.  

Double exactly!




Just trying to help, with the physics, Cboling.
Nothing quiets naysayers better than raw mathematics. 
It's a shame for you to be overran by people telling you how it won't work, before you even get a chance to ride it. 
Not much of a reason for you to keep helping us, is it? 


If it's too soft but you want to keep it, I'm here to help if you wanna try finding correct linkages.  
Since you live in an apartment, maybe I can give you the measurements and you can find something cheap.  Or somebody here will surely try to make some, to offer as a kit. 
But, you're the man with the plan!  I'll keep tuning in for updates! 



Watch the "For Sale" section for the M word, or PM me.  
Otherwise, you'll be severely threadjacked.  




Good luck with your rebuild!  Loving that headlight bucket.  Post more pics!  

Quote from: cboling on July 12, 2009, 07:03:38 AM
As for converting the measurements in the last post, I am coming up with 548 lbs / Inch using the 9.8 kg /mm. Can someone else with better math confirm this?

That's also what racetech gives.

Product search -> Street   http://www.racetech.com/

Quote from: cboling on July 12, 2009, 08:48:10 AM
(Thanks goodness I don't have a lot of neighbors with babies.!!! Peeeeeeeewwww!!)

and I am counting 4 free coils.

As I see it in the photo the GS shock has 5 free coils and the R6, 4. That make the R6 stiffer... but I also see it might me a little wider and that makes it softer. 

Do you have measurements for the Yamaha shock?

I can get the measurements for the Yamaha spring a little later today.

Quote from: wladziu on July 13, 2009, 10:11:13 PM

Quote from: ineedanap on July 13, 2009, 08:39:50 PM
Let the guy try.  Lets see how it works. 

Double exactly!




Just trying to help, with the physics, Cboling.
Nothing quiets naysayers better than raw mathematics. 
It's a shame for you to be overran by people telling you how it won't work, before you even get a chance to ride it. 
Not much of a reason for you to keep helping us, is it? 

Oh yea ... the nay sayers are impressed by the "raw mathematics" ... especially this gem ...

Quote from: wladziu on July 13, 2009, 02:54:00 PM
The weights aren't very necessary.  Just the lengths. 

Which was of course preceeded by ...

Quote from: wladziu on July 13, 2009, 11:07:24 AM

If you can find the weight of the donor bike, minus swingarm/tire assembly, length of the swingarm and the linkages (center of bolt holes) (and the same for a GS), just plug it into Newtonian two-dimensional vector physics for torque.  
Comparative spring rate, based on GS linkages, isn't gonna prove very much.  The shock could be valved differently, the spring might be progressive ( ).   Unless you find the vector sums of everything involved, you're not gonna know until you ride it.  

If it turns out to be too soft, then you can play around with Buddha's "leverage" (aka, torque) by changing linkage lengths.  Based on the same math I just talked about, but only using GS measurements.  

That's actually the best way, if you have enough room to add the proper linkage:  
Find a better shock with full functionality, then alter the lnkage until it provides the proper support.  IF you've got enough under-body room to clear said linkage.  Of course, if the linkage-swingarm triangulation is reversed, you'd be shortening (not lengthening), and therefore you wouldn't need to worry about clearance.  

Yea that's all you need to get it to work ... see its a lot easier to get all this than run it round the block see ... Yea just measure these things from a bike you dont have and even if you did, you cannot measure it without pulling 80% of it apart ... very easy ...

Again, I only posted about my experience with the beefier looking shocks from a GSXR on my sv.

I posted it as a caution before he tosses the GS shock or destroys it getting the R6 one to work like pulling springs and what not, or something like that.
Unlike you I dont start asking for the impossible before making a suggestion to people. I ran the kat shock a few years (before the net showed up in the real sense of the world - 95-98) ... then I posted about it when this site showed up in its previous iteration. I actually sold a few in 98/99 to the old mailing list  we had ... if anyone remembers that. In effect I only buy them when people have asked me ... and in case you didn't know ... I am loaning some tools and stuff to cboling as we speak.

You can post all the obscure crap you want and ask for weights and lengths of assemblies and what not Wladizu ... its all well and good in theory but,
In the real world, where the vast many of us who dont have the benifit of a "few missing screws" have to live ... that information isn't easy to get, nor is it neccesary ... and if cboling needed his shock tested, I'm sure he's gonna find a willing accomplice to come over to his place on a GS and ride around. If I had a shock I had to run, guess what, I'd call lopee, or one of the other locals I got and get my shock on their bike and get them to ride it a few hours/days and tell me.

Effectively, all the unknowns will disappear if you ride it.

I can ask for compression ratio, the flow rates of the heads, the flow rates of the pipes, the carburetor exact orifice dimensions and all the other in calculable parameters before suggesting jets to people. However its easier and cheaper to tell em to run 125/40/1/3 turns ... and try it, if it feels rich/lean etc, just adjust after by feel.
Before I landed on 125/40 ... I copied it out of the canadian spec section in the suzuki manual.

Essentially, throw it on, try it first in your safety zone, and then ever larger circles till you are confident in it.

Once again ... try it but dont destroy the GS shock, it may well be what you have to fall back upon ... though the local Junk peddler could bail you out ... in a pinch ... pay for postage and the gs shock I gots laying about can be send over in a jif.

Cool.
Buddha.