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Discussion Starter · #1 ·
Does anyone out there know if the Gen 3 fork springs are the same as the Gen 2’s? I’d like to replace the stock springs and there isn’t anything specifically for the Gen 3. But plenty of Gen 2 options are available. Thanks all!!
 

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2022 Pearl Lava Orange
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I can give you specifics tomorrow afternoon after my gen 3 ddc install. I'll post pics. Cogent was very adamant the gen 3 has stiffer oem fork springs than previous gens. As high as .75kg according to their techs. I'm not setup to test spring rates so all I can provide is diameter, length and preload from the factory springs.
I don't get much fork dive under hard breaking with my 230lbs on board. I'll be thrilled to not need to buy springs for my weight. It would be a first.
 

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Discussion Starter · #3 ·
I can give you specifics tomorrow afternoon after my gen 3 ddc install. I'll post pics. Cogent was very adamant the gen 3 has stiffer oem fork springs than previous gens. As high as .75kg according to their techs. I'm not setup to test spring rates so all I can provide is diameter, length and preload from the factory springs.
I don't get much fork dive under hard breaking with my 230lbs on board. I'll be thrilled to not need to buy springs for my weight. It would be a first.
Length, diameter, etc is all I need, so that will be an enormous help. I just want to know if springs meant for a Gen 2 will fit into the Gen 3 forks without modification to the springs, forks, or need of spacers.

I’m looking to put Progressive springs in my Gen 3 and they only have springs for the Gen 2. Thanks again!!
 

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Keep in mind that the progressive springs may well be lighter (even at the top of their range) than the stock 2022 springs. What are you trying to change/accomplish? A set of DDC's and the stock springs may well be (and probably are) a better suspension choice. From what I can find:

Stock pre-2014.5 straight rate springs - .40kg/mm
2014.5+ straight rate springs - .56kg/mm
Cogent dual rate - .40 - .60 kg/mm
Progressive - .45 - .71kg/mm
...and apparently Gen3 straight rate - .75kg/mm


Dave
 

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Discussion Starter · #5 ·
Keep in mind that the progressive springs may well be lighter (even at the top of their range) than the stock 2022 springs. What are you trying to change/accomplish? A set of DDC's and the stock springs may well be (and probably are) a better suspension choice. From what I can find:

Stock pre-2014.5 straight rate springs - .40kg/mm
2014.5+ straight rate springs - .56kg/mm
Cogent dual rate - .40 - .60 kg/mm
Progressive - .45 - .71kg/mm
...and apparently Gen3 straight rate - .75kg/mm


Dave
I understand. I don’t ride hard and I’m fairly lightweight. I’ve put progressive springs in my past KLR’s (two Gen 1’s and one Gen 2), and I like the way they feel. They just work for me. I’m hoping the Progressive springs for the Gen 2 will work.
 

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Discussion Starter · #7 ·
The stock springs are better than the gen 2 but still are not as long as the progressive springs. The progressive springs kit has been great to have on my 22
So you put Progressive springs in your 22? That’s great!! Where did you get the springs? I found them at Procycle, but it’s just the springs.
 

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The Progressive Suspension brand springs will come with Instructions on how to cut Preload spacers for Your Weight.

So, still some Modification Needed! No Free Lunch.
 

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Update:
My gen 3 oem fork springs are 430mm x 34mm. They are stiff brother! Very heavy wire. The preload spacer is 224mm! 14mm of preload holy cow.
Here's the kicker. I pulled the right side spring and spacer. Fully collapsed I measured the oil height... yikes, 175mm! wtf kawasaki? It had maybe 6 ounces(being generous) of dirty black oil in there. I'm going to bed and I'll do the left side in the morning when I'm not so disappointed...
Safe to say changing the oil and setting the proper oil height would make a big improvement so the ddc should be worlds better. Man I'm still flabbergasted by the poor factory setup on the forks. Must have been a Monday.
 

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Yep. 2 bottles.
Suspension maintenance and tuning is something I learned years ago. I got tired of handing money over to Suspension shops. With my height and weight, pretty much any new offroad bike I bought needed springs and a revalve right out of the gate. The WP 4cs rabbit hole was the final straw...
 

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Discussion Starter · #14 ·
Update:
My gen 3 oem fork springs are 430mm x 34mm. They are stiff brother! Very heavy wire. The preload spacer is 224mm! 14mm of preload holy cow.
Here's the kicker. I pulled the right side spring and spacer. Fully collapsed I measured the oil height... yikes, 175mm! wtf kawasaki? It had maybe 6 ounces(being generous) of dirty black oil in there. I'm going to bed and I'll do the left side in the morning when I'm not so disappointed...
Safe to say changing the oil and setting the proper oil height would make a big improvement so the ddc should be worlds better. Man I'm still flabbergasted by the poor factory setup on the forks. Must have been a Monday.
Wow! No wonder that front fork is so stiff for me. I’m only 155 lbs. In the past, and was able to just replace the springs without changing the spacer. We’ll see what happens with this one. A million “thanks” for the update!!

One more question. I usually use Honda 5W fork oil. Would you recommend anything better/different than that?
 

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I'm running ddc valves and they want 5w but if you're just doing new springs, I'd probably suggest sticking with 10w. Or mix your own ratio to get 7w. Belray makes a 7w as well. Honda fork oil is good stuff but the 5w and no additional valving might be problematic. Mind you, I'm just applying common sense. I'm sure someone else will chime in with better direct experience.
My factory preload was 17mm. That's a good way to get a stiff feel for sure.
I'd recommend 8mm preload and 130mm oil height. Factory had my oil height at 175mm!
 

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I can give you specifics tomorrow afternoon after my gen 3 ddc install. I'll post pics. Cogent was very adamant the gen 3 has stiffer oem fork springs than previous gens. As high as .75kg according to their techs. I'm not setup to test spring rates so all I can provide is diameter, length and preload from the factory springs.
I don't get much fork dive under hard breaking with my 230lbs on board. I'll be thrilled to not need to buy springs for my weight. It would be a first.
If you had some help, you could get a pretty accurate spring rate by standing the spring on a stable, level surface, semi-balancing a known weight on top while you stabilize it and having someone measure the compressed length to compare to unloaded. Or, fasten a fork tube vertically to something solid, drop in the spring and spacer, pull the upper tube so it's above the spacer, then put your known weight on it (the heavier and more compact, the better). Let it compress the entire assembly, carefully remove the weight, then measure how far the spring extends above the top of the tube when unweighted. You'd have the uncontrolled variable of stiction, but it would be close enough for government work.

EDIT You actually wouldn't have stiction to contend with. Clamp the fork in an upright position,, clamp the upper tube (gently) in position so that 3 inches or so of spring extend beyond the top of the tube and measure and record the actual distance (top of spring to top of tube). Then apply the weight and measure the compressed distance. Divide the mass of the weight in kgs by the distance it compresses the spring in mms, and the result is the kg/mm spring rate (which will, for all practical purposes, be a constant all the way to coil bind).
 

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What could go wrong! Ha. Sounds like a "hold my beer and watch this" moment.
Was going to tell you to be sure to have video rolling when you tried it, but decided to just try it myself, lol. I clamped the lower fork tube to a low shelf on my welding table, then clamped a stop block to the upper tube so it was stoppered against the table top in a semi collapsed state, which took stiction out of the equation. The assembly was plumb in both directions as measured by a professional quality torpedo level. I dropped in a spring and put the standard spacer on top. with a piece of 2x6 resting on the spacer as a cushion, and after bouncing it to settle it, it measured 179.5mm from the top of the fork tube to the top of the spacer. I then centered a 16.56kg cement block on the top, again bounced it to settle it, and got a reading of 136.5mm. I repeated the process 5 times, getting consistent measurements each time. Taking 16.56kg divided by 43mm yields a spring rate of 0.38kg/mm. Then I swapped out the spring for the one from the other side of the fork and repeated all steps. That spring (which was 2.3mm taller at the outset) dropped a repeatable (again, 5 times) distance of 40.5mm for a spring rate of 0.41kg/mm. It may not be spring rate test bench accurate, but I'd bet its single decimal accurate. This is a 20k mile '08 with, to the best of my knowledge, OEM springs (which the measured rates would seem to bear out). It can be done, along, and it's actually not that difficult. The only downside is that now I know for certain that I need to purchase stiffer springs.
 

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KLRs: 2013, 2005, 1998; 2017 HD Electraglide Ultra
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It’s easier to calculate the spring rate by referring to the formula on many engineering websites. You need to measure the external diameter of the coil, the thickness of the spring wire, and count the number of coils. Then crank those into the formula. Depending on the accuracy of your measurements, it should get you within 5% of the actual spring rate, which is close enough to determine which springs you have.
 

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It’s easier to calculate the spring rate by referring to the formula on many engineering websites. You need to measure the external diameter of the coil, the thickness of the spring wire, and count the number of coils. Then crank those into the formula. Depending on the accuracy of your measurements, it should get you within 5% of the actual spring rate, which is close enough to determine which springs you have.
My measurements didn't take long at all, but that speed was predicated on already having the forks off of the bike for a fork oil change. Actually, it's easier to 𝙚𝙨𝙩𝙞𝙢𝙖𝙩𝙚 spring rate using a formula but the actual rates will depend on consistency in both manufacturing process and metallurgy. I'm sure my factory installed springs were estimated to be identical (with a spec of 0.40kg/mm), yet even my fairly crude appearing methodology has revealed an actual 𝙘𝙖𝙡𝙘𝙪𝙡𝙖𝙩𝙚𝙙 rate that is demonstrated to have subtle yet quantifiable differences. It'll be interesting to plug the measurements of my springs into a formula and see if the small differences in free length yield rate differences similar to the demonstrated actual differences. Of course, none of those subtleties will matter to a KLR. If you installed a 0.40kg spring in the left fork, and a 0.60kg spring in the right, it would probably ride like a bike with a pair of 0.50kg springs in it (though it might increase stiction and produce a noticeable hinkiness in a Gen 1 with its more flexible forks). The engineering part of my brain says that if I were a race tech, especially on a road bike, I would be installing springs of identical length and measured rate in both forks, in order to avoid inducing fork stiction/changes in wheel camber and forward alignment that could result from bowing of the fork tubes caused by unequal rates.
stiction/changes in wheel camber and forward alignment that could result from bowing of the fork tubes caused by unequal rates.
 
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