KYB SSS Valving Input Please
 

I put a full 2008 YZ450 Front end on my 2000 GasGas XC300. I am 51yrs old, (riding 42 yrs). 6' 4", 250lbs in street clothes.*I enjoy all kinds of riding but prefer difficult single track, trails and hills.*(probably*B-C Enduro). *
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I changed springs to Racetech 48 with 5mm of preload.* I have tried to soften the forks about 7 times so far and below is what I have now for a tune.

The forks are still too stiff on trail trash even with the compression adjusters complete loose. They work great for big hits but they are too stiff most for most all else.
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Midvalve
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Nut
Washer
11mm*(x1) 0.25mm
12mm (x1) 0.11mm
14mm (x1) 0.11mm
16mm (x1) 0.11mm
18mm (x1) 0.11mm
13mm (x1) 0.11mm
20mm x0.045 (x3)* 0.11mm (Stock had 4)
Piston
20mm x 0.045" (x2)*0.11mm (Stock had 4)
17mm x 0.045" (x2) 0.11mm (Stock had 3)
11mm x 0.01" (x2) 0.25mm
17mm x 0.01" (x3) 0.3mm
17mm x 0.045" (x1) 0.11mm (moved from above)
Collar
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Estimated Midvalve Float* 0.5mm (as I removed*two*0.11mm shims)
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Base Valve
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​Nut
Cup Washer 4 holes
​Spring
big silver washer with collar
​​Piston
​32mm (x9) 0.11mm
20mm (x1) 0.11mm (from*midvalve stack)
32mm (x6) 0.11mm* (stock was 18x 32mm)
30mm (x1) 0.11mm
28mm (x1) 0.11mm
26mm (x1) 0.11mm
24mm (x1) 0.11mm
22mm (x1) 0.11mm
20mm (x1) 0.11mm
18mm (x1) 0.11mm
16mm (x1) 0.11mm
20mm (x2) 1.58mm
11mm (x2) 0.25mm
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310cc 5w BelRay oil
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It seems that the compression screws do not have a big impact on the dampening.* Any input would be appreciated.

I know sht about actual valving. I cheated and a mate revalved to KTech Club specs. Much betterer.

Opening to full open on the clickers can be more harsh as it blows through then gets stiff real quick. Best keep within several clicks of middle and find best comprise. Then revalve if that's not good enough. Any more clicks is out of range.

Sorry can't give actual valving specs as I don't have them. But they can be made good for technical.

Why all this lbs talk.. now I have to do conversions!

Being YZF450 forks, they'll probably have quite firm ICS rates. This adds quite a bit of firmness, especially when added with firmer preloaded springs as well.

.5mm is quite a large float, and your mid very soft.

I'd go back to around .4mm float, and a more traditional mid valve.

Address the basevalve!!

​​Piston
​32mm (x9) 0.11mm
20mm (x1) 0.11mm (from*midvalve stack) --- I don't like crossovers this small. I'd be more around 26/28mm if using.
32mm (x6) 0.11mm* (stock was 18x 32mm)
30mm (x1) 0.11mm
28mm (x1) 0.11mm
26mm (x1) 0.11mm
24mm (x1) 0.11mm
22mm (x1) 0.11mm
20mm (x1) 0.11mm
18mm (x1) 0.11mm
16mm (x1) 0.11mm ----> this is your main issue.
----------add clamp 14mm x.3mm
20mm (x2) 1.58mm
11mm (x2) 0.25mm

Simply changing the clamp to a 14/13mm shim x .3mm you'll soften the whole stack up. You may wish to pull a couple more face shims as well.

Also, considering that you've upped spring rates, you may wish to add a bit more rebound control as well.

Note, just checked spring rates, and they should be fine. Even if you have the firmer ICS springs.

So I'd add another face shim back to both sides of the mid valve. That will close your float to approx .39mm.

Then soften the basevalve to something like the following.

32 (6)
26
32 (6)
30
28
..
14.3 (or 13)

Then test.

Thank you both.

Jakobi -So to make sure I understand you correctly I should modify it like this?

Midvalve
*
Nut
Washer
11mm*(x1) 0.25mm
12mm (x1) 0.11mm
14mm (x1) 0.11mm
16mm (x1) 0.11mm
18mm (x1) 0.11mm
13mm (x1) 0.11mm
20mm x0.045 (x4)* 0.11mm (Stock had 4)
Piston
20mm x 0.045" (x3)*0.11mm (Stock had 4)
17mm x 0.045" (x2) 0.11mm (Stock had 3)
11mm x 0.01" (x2) 0.25mm
17mm x 0.01" (x3) 0.3mm
17mm x 0.045" (x2) 0.11mm (moved from above)
Collar
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*
Base Valve
*
​Nut
Cup Washer 4 holes
​Spring
big silver washer with collar
​​Piston
​32mm (x6) 0.11mm
26mm or 28mm (x1) 0.11mm (I will see if I can find one in a set of WP43s)
32mm (x6) 0.11mm* (stock was 18x 32mm)
30mm (x1) 0.11mm
28mm (x1) 0.11mm
26mm (x1) 0.11mm
24mm (x1) 0.11mm
22mm (x1) 0.11mm
20mm (x1) 0.11mm
18mm (x1) 0.11mm
16mm (x1) 0.11mm
14mm or 13mm (x1) 0.3mm [U](I will see if I can find one in a set of WP43s)
Do I remove both 20mm and the 11mm or do I keep the 11mm?

Thank you for the help!

The shims below the main stack are referred to as the bleed stack. By running as below they don't block any ports off, which isn't needed for off road so I'd keep them as is:

20mm (x2) 1.58mm
11mm (x2) 0.25mm

Have a look at the assembly and where they sit and you'll see what I mean.

Everything above looks pretty good.

Ok so my Base Valve will look like this?
*
​Nut
Cup Washer 4 holes
​Spring
big silver washer with collar
​​Piston
​32mm (x6) 0.11mm
26mm or 28mm (x1) 0.11mm (I will see if I can find one in a set of WP43s)
32mm (x6) 0.11mm* (stock was 18x 32mm)
30mm (x1) 0.11mm
28mm (x1) 0.11mm
26mm (x1) 0.11mm
24mm (x1) 0.11mm
22mm (x1) 0.11mm
20mm (x1) 0.11mm
18mm (x1) 0.11mm
16mm (x1) 0.11mm
14mm or 13mm (x1) 0.3mm
20mm (x2) 1.58mm
11mm (x2) 0.25mm

I see your point how adding the 13/14mm will soften the whole stack.

So if I understand correctly, my present stack does not have a bleed shim because the 32mm shims are placed directly against the piston? A bleed shim in this stack might be an 11mm placed between the piston and the first 32mm of the main stack?

This may be a silly question but if I can not get a single 13 or 14mm x 0.3mm thick can I build it from multiple thinner shims (adding up to 0.3mm) and get the same results?

I found that I have a pair of 21mm and a 24mm. Will they work in place of the 26 or 28 or will that make it too soft?

I also have a pair of 12mm, 14mm and 16mm 0.11mm thick. Can I stack these to get close to the 13/14mm 0.3mm or would it be better if I just order the correct ones?

If I am ordering shims should I get the metal free pistons too or don't replace them until they break?

You can try the 14x.11mm clamp. Usually just aim for more to allow more room for the shims above to flex over the clamp if required.

You can try the 24mm crossover if you like as well, or simply leave the crossover right out and run a straight stack.

With the KYB they have an option for a bleed stack. This essentially bypasses the clicker. By running your 11.25 (2) and the spacer at the bottom of your compression stack you are leaving the small ports open, and bypassing this.

This is different to what is referred to as a bleed shim, and that is exactly what you have said above. It sits between the face shim and piston face to allow the ports to be partially open at all times, allowing bleed.

The free pistons, if they aren't broken and look in good condition I would simply drill them to avoid the pressure build up that breaks them. Otherwise if you want to drop some coin you can get the metal ones.

Thank you Sir!

So I could actually run the 12mm under the 14mm to make it a bit thicker and allow for more room for the compression stack to move.

For my situation is there a benefit to leaving the bleed stack in place or should I invert it as shown below?

Am I correct that the 24mm in the middle of the twelve 32mm will soften the initial part of the stroke when compared to the consecutive stack of 32mm?

Nut
Cup Washer 4 holes
​Spring
big silver washer with collar
​​Piston
​32mm (x6) 0.11mm
24mm (x1) 0.11mm
32mm (x6) 0.11mm
30mm (x1) 0.11mm
28mm (x1) 0.11mm
26mm (x1) 0.11mm
24mm (x1) 0.11mm
22mm (x1) 0.11mm
20mm (x1) 0.11mm
18mm (x1) 0.11mm
16mm (x1) 0.11mm
14mm (x1) 0.11mm
12mm (x1) 0.11mm
11mm (x2) 0.25mm
20mm (x2) 1.58mm

Instead of thinking about parts of the stroke, think about shaft speeds and fluid displacement.

With the crossover, it means that for slower shaft speeds that only displace a certain amount of fluid over a certain time, it'll allow the first 6 shims to flex easier, offering less resistance. For faster shaft speeds and higher displacement those shims will flex to contact the other 32's and continue to build damping.

Running the 12 under the 14 changes the clamp/pivot and will soften the whole stack further again..

I'd try this.

​​Piston
​32mm (x6) 0.11mm
24mm (x1) 0.11mm
32mm (x6) 0.11mm
30mm (x1) 0.11mm
28mm (x1) 0.11mm
26mm (x1) 0.11mm
24mm (x1) 0.11mm
22mm (x1) 0.11mm
20mm (x1) 0.11mm
18mm (x1) 0.11mm
16mm (x1) 0.11mm
14mm (x1) 0.11mm
20mm (x2) 1.58mm
12mm (x1) 0.11mm --can remove if you like, or leave in place. Won't influence anything.
11mm (x2) 0.25mm

If it still feels to firm just order a 13.3 from somewhere as your new clamp and it'll soften things further. Changing the clamp is a pretty noticeable/significant change.

Thank you Sir! I will work on it this weekend.

Let us know how you get on with it.

MX-Tech is 1.5 hours away from me so I ordered the 26mm and 14mm shims to save time.

I dont have a SSS front end yet but this is a informative thread. Subscribed.

I received my shims late so I will need to do the work next weekend.

No worries mate! ;)

Jakobi - I was able to swap out the shims last night and I went for a quick ride today. I think your suggestions that took care of my problem. The forks soak up the small stuff much better and they fell very progressive. I need to go out for a real ride to get them dialed in. I will try to do that next weekend. Thank you again Sir!

You beauty!

Have you managed to put a few hours on them yet?

Zman, Any Update on how they are working for you??

I wish I had some time to try them out and we were supposed to go this last weekend but weather turned really lousy. If all goes well I will be able to go soon. I need to drive min 1:20 min to get to a mediocre place to ride.

Ya I know the weather turned lousy. We froze Friday riding. It was snowing 15 miles west of us and we did not have our winter gear. But the boy wanted to try out his new to him 10 ec250.

I here you about having to drive. We have a Min 1 hour drive. Updates us when you can.

How about now?? Don't tell me you've been as bad as me and haven't thrown a leg over in a month!! No wonder I've had a short fuse the last couple days..

:(
Short answer is no. Since I finished the forks, weather went really bad In Chicago, Followed by a crazy work schedule with a week in Japan and I am now wrapping up another work week in Germany. I plan to run a family enduro in Marquette Michigan on July11th. Too much going on to have fun right now but I have it on the calendar!:D

You've travelled more in the last weeks than I have in my life! :D

I can be a blessing and also a curse.

You may miss the FES if you plan on going in July ... reliable sources say it is June 11th.:cool:

My mistake, it is June 11th not July 11th.

Jakobi - The forks work way Way WAY better now! They are much softer and do not transmit slower trail trash like before. The forks soak up big sand whoops with no problem! Faster speed rocks and roots still transmit through the bars more than I like and really big hits seem a bit too firm. I have the compression clickers all the way out and I wish I had a few more clicks to try.

The clickers did not seem to make much difference, but that may be because I was at the end of adjustment. I think they are very close but I still need to soften the a touch more. Based upon your previous recommendation it sounds like I should swap out the 14mm clamp for a 13mm clamp or I can run the 12mm (I already have) under the 14mm clamp?

For the big hits I suppose I can drop another 10 to 20cc of oil out of the forks or should I try that after changing the valving?

Thanks again, this was a huge improvement and it is very close!

Having clickers way out is never a good plan they will make little difference but they will cause the stroke to blow through then spike as they orifice limit.

As F5 said. Too soft can be read as a spike/harsh feeling as well.

How much oil are you running in the outers at the moment?

Given that the change has been a move in the right direction, I'd be inclined to drop a 13 clamp on the base valve and see how it feels. (You could throw a 12 clamp on one leg, and the damping will average across the two, if you didn't want to wait on shims or pull 2 legs down again).

Aim to have the clickers in the middle. A few clicks each side of 13 seems to be the sweet spot.

It sounds like you like a bit more free bleed as you tend to have the clickers open. You might like a touch more float with no changes to the base valve, but I personally wouldn't go this route at this stage. Try as above and see if you like it.

Thank you both.

The harshness is hitting roots and rocks at speed where the same size roots and rocks size seem to provide less feedback when I go slower.
I am presently running about 310cc of maxim 5w. I was thinking maybe 290 or 300cc

Should I run the 12mm or 13mm in addition to the 14mm or in place of the 14mm?

Understood.

So fast shaft speed. Volume of fluid that needs to be displaced over a short period of time. I think you'll find the smaller clamp will help.

I'd put the 13 or 12 in addition to what is already there.

I've never really considered a bit of feedback through the bars to be a bad thing, as long as it's not deflection. I guess I mean I don't mind feeling the ground beneath me as long as the chassis isn't being disturbed. I know not everyone feels the same way though. It's all very subjective.

I don't think I'd worry with the oil volume at this stage. That is more in line with your bottoming resistance and air spring. This sounds more like short sharp edges that aren't necessarily using a lot of stroke, but they forks aren't reacting fast enough to be plush. At lower speeds you have similar displacement over a greater duration.

I agree and I do not want to be disconnected from the trail input but I have tendonitis that comes and goes. Too much jarring feedback makes it worse. These KYBs replaced some WP43s done by LTR that were pretty good for what they were and I did not have tendonitis problems with them. I expected the KYBs to be better across the board but I guess I need to do a little more tuning to get there. I sure am glad I like working on dirtbikes!:D

The 12mm (I already have) are only 0.11mm thick. Do you think it is worth adding the 12 x 0.11 below the 14mm clamp or should I order up some thicker 13mm shims?

Oil Level - To test the stroke I was intentionally hitting big sand whoops faces to try to bottom the forks. They soaked up the hit great but they never came close to bottoming so I do not think I will be able to make full use of the travel unless I land some big jumps and my GG rarely sees the MX track. That is why I thought I could use a bit more air volume to try to use more of the stroke.

Before I pull them apart again I will double check the sag in the front and rear to make sure everything is matched. I think my fork spring preload is between 4 to 5 mm with the 48 springs.

One more thing, during the first enduro loop the front end was washing out a bit so between loops I dropped the front end about 3mm and that helped the front wheel stay put but it got firmer which is when I loosened the clickers all the way out. I think the ride height is about correct now so once I get the dampening sorted out I should be set.

Try the 12mm clamps straight up on both legs if you want (place below the 14). If it's too soft then, you could look at the 13mm.

It's interesting that placing more weight on the front resulted in your wanting to soften them more. Usually you'd want to firm them to keep them up in the stroke a bit.

I find rebound helps a lot in push/tuck as well. Basically how well it settles and tracks when weighted and tipped in. Too quick and it'll want to stand up and blow the turn. Too slow and it'll tuck a bit.

As always thank you for the education and guidance! I will work on them this weekend.

No worries. Next comes the real struggle. When does close enough become good enough? :D

Indeed!!!!

I installed the 12 x0.11mm below the 14mm and I think that took care of my issue. They feel great and now I can have the compression clickers in the middle.

Side question - has anyone ever found coagulated snotty stuff that looks like egg whites in your fork oil? I am not sure if it was the result of mixing two different brands of fork oil because I ran out of Maxim. It was only in one fork and not both.

Thanks again!