KYB SSS Valving Input Please
- Thread starter Zman
- Start date
swazi_matt
Active member
I am busy servicig my forks, anyone let me know whow much oil to put in the outer fork tubes. is 300ml a good start for a slow rock rider?
PS i had lots of eggwhite slime come out of my forks, but that might be because the seals lasted so well
PS i had lots of eggwhite slime come out of my forks, but that might be because the seals lasted so well
swazi_matt
Active member
Thanks. Measured the oil out of the other fork at 300 so went with that
Jacob 'Berg
Member
Rather than start a new thread on same subject I'm asking here as a SSS newbie.
From reading through I'm wanting the same sort of compliance and I weigh similar but a good bit shorter lol.
Just got a set if 2007 yz250f forks and putting them on my 2011 250. Haven't fitted them yet awaiting parts so figured I'd start with the valving while I'm waiting and copy a working setup.
Pulled the base valve and it's different than that posted at the start here. All standard from what I can see. There is some tool marks inside the forks but base valve stacks were still peened
Base valve
Nut
Cup washer with 4 holes
Check plate
Piston no bleed holes
32x0.1x17
30x0.1
28x0.1
26x0.1
24x0.1
22x0.1
20x0.1
18x0.1
16x0.1
14x0.3
14x0.3
20x1.6
11x0.3
11x0.3
14x0.1
16x0.1
18x0.1
20x0.1
22x0.1x5
Is the 26-28 crossover needed?
What do I do with this stack below the spacer (20x1.6)?
Haven't got into the mid and rebound yet need a clamp for the damper rod.
Noticed 1 leg had grey oil looks like the shaft iwo the ics pistion has worn through the anodizing over a 30mm section. Main damper rods look good. Will maybe get the ics shafts redone if I can get then riding good.
And 2 5mm holes in the ics pistion body recommended?
Thanks for any help
From reading through I'm wanting the same sort of compliance and I weigh similar but a good bit shorter lol.
Just got a set if 2007 yz250f forks and putting them on my 2011 250. Haven't fitted them yet awaiting parts so figured I'd start with the valving while I'm waiting and copy a working setup.
Pulled the base valve and it's different than that posted at the start here. All standard from what I can see. There is some tool marks inside the forks but base valve stacks were still peened
Base valve
Nut
Cup washer with 4 holes
Check plate
Piston no bleed holes
32x0.1x17
30x0.1
28x0.1
26x0.1
24x0.1
22x0.1
20x0.1
18x0.1
16x0.1
14x0.3
14x0.3
20x1.6
11x0.3
11x0.3
14x0.1
16x0.1
18x0.1
20x0.1
22x0.1x5
Is the 26-28 crossover needed?
What do I do with this stack below the spacer (20x1.6)?
Haven't got into the mid and rebound yet need a clamp for the damper rod.
Noticed 1 leg had grey oil looks like the shaft iwo the ics pistion has worn through the anodizing over a 30mm section. Main damper rods look good. Will maybe get the ics shafts redone if I can get then riding good.
And 2 5mm holes in the ics pistion body recommended?
Thanks for any help
Jakobi
Super Moderator
The crossover helps with slow speed bump compliance. Some people prefer a straight tapered stack, some like a crossover.
If you look at the post for the basevalve you will see it has some holes around the base of it which allow fluid to bypass. It's known as the bleed stack, and the stack below the spacers are what covers that. Works in conjunction with the clicker.
Great thanks.
Would I be right in thinking having 2x 14x0.3 for the clamp it might be quite soft by giving a large gap for the stack to deform into?
Once I get the mid and rebound out I'll see what I have to play with. I'll add the crossover If I have shims spare. If not ill ride with a few less of the 32s and see how it feels.
I thought I had my marzocchi 45s working well until I rode a 2016 husky fe250. If I can get anywhere close to how it felt I'll be very happy. Not soft but compliant, ate everything and generated so much front end grip
I got into the mid and rebound today.
Reb
Nut
Washer
10x0.25x2
12x0.1
14
16
18
13
20x0.1x3
Piston
Mid
20x0.1x3
18
16
14
11x0.3x2
17x0.3x2
I make float to be 0.30mm
Post is 5.3mm
Cup washer is 2mm
Piston recess 1mm
Stack is 2mm
Would I be right in thinking having 2x 14x0.3 for the clamp it might be quite soft by giving a large gap for the stack to deform into?
Once I get the mid and rebound out I'll see what I have to play with. I'll add the crossover If I have shims spare. If not ill ride with a few less of the 32s and see how it feels.
I thought I had my marzocchi 45s working well until I rode a 2016 husky fe250. If I can get anywhere close to how it felt I'll be very happy. Not soft but compliant, ate everything and generated so much front end grip
I got into the mid and rebound today.
Reb
Nut
Washer
10x0.25x2
12x0.1
14
16
18
13
20x0.1x3
Piston
Mid
20x0.1x3
18
16
14
11x0.3x2
17x0.3x2
I make float to be 0.30mm
Post is 5.3mm
Cup washer is 2mm
Piston recess 1mm
Stack is 2mm
Last edited:
Jakobi
Super Moderator
The clamp OD determines the pivot that the rest of the stack will flex around. I don't think the height has a whole lot of influence unless if the stack is light enough that the face shims flex to hit the backer. Hardly an issue on this.
In my set I made some changes to the mid (comp and rebound) and the basevalve.. but to be honest just softening the BV up a touch from where it is will probably suffice.. at least enough to allow the bike to be punted around and a baseline for improvement to be found..
I'd probably start somewhere around 12 face shims, with a large-ish crossover around half way through em.
In my set I made some changes to the mid (comp and rebound) and the basevalve.. but to be honest just softening the BV up a touch from where it is will probably suffice.. at least enough to allow the bike to be punted around and a baseline for improvement to be found..
I'd probably start somewhere around 12 face shims, with a large-ish crossover around half way through em.
ah I see.
For now I have stolen a 22 out of the bleed stack (good move??
) and moved it up as a crossover to get me something to ride.
Anything to be gained by replacing the majority of bleed stack with another 20x1.6 spacer (as per the OPs forks) or should I flip the stack, moving the 11x0.3x2 closest to the bleed ports, to allow some free bleed without being influenced by the 24x0.1X4 shims?
Mid and rebound left as is.
Comp
Piston no bleed holes
32x0.1x6
22x0.1
32x0.1x6 (was x17)
30x0.1
28x0.1
26x0.1
24x0.1
22x0.1
20x0.1
18x0.1
16x0.1
14x0.3
14x0.3..... ..... ..........Alternate bleed
20x1.6 ........... ........ 22x0.1x4
11x0.3 ...... ............. 20x0.1
11x0.3 ........... ........ 18x0.1
14x0.1 ............ ....... 16x0.1
16x0.1 .......... ......... 14x0.1
18x0.1 .... ............... 20x1.56
20x0.1 .... ................11x0.3
22x0.1x4 (Was x5).....11x0.3
Post with bleed holes
This will hopefully give me a decent base line to ride.
Brake adapter arrived so I turned some spacers on Saturday.
Just need a axle nut, fork guards and a steering stop figured out (bumper cut from some old tyre to get going) and im good to go.
Thanks
For now I have stolen a 22 out of the bleed stack (good move??
) and moved it up as a crossover to get me something to ride. Anything to be gained by replacing the majority of bleed stack with another 20x1.6 spacer (as per the OPs forks) or should I flip the stack, moving the 11x0.3x2 closest to the bleed ports, to allow some free bleed without being influenced by the 24x0.1X4 shims?
Mid and rebound left as is.
Comp
Piston no bleed holes
32x0.1x6
22x0.1
32x0.1x6 (was x17)
30x0.1
28x0.1
26x0.1
24x0.1
22x0.1
20x0.1
18x0.1
16x0.1
14x0.3
14x0.3..... ..... ..........Alternate bleed
20x1.6 ........... ........ 22x0.1x4
11x0.3 ...... ............. 20x0.1
11x0.3 ........... ........ 18x0.1
14x0.1 ............ ....... 16x0.1
16x0.1 .......... ......... 14x0.1
18x0.1 .... ............... 20x1.56
20x0.1 .... ................11x0.3
22x0.1x4 (Was x5).....11x0.3
Post with bleed holes
This will hopefully give me a decent base line to ride.
Brake adapter arrived so I turned some spacers on Saturday.
Just need a axle nut, fork guards and a steering stop figured out (bumper cut from some old tyre to get going) and im good to go.
Thanks
Last edited:
Jakobi
Super Moderator
A 22 crossover might be a bit small but OK to try. You could probably steal the 28 or 26 out of the main stack without it causing too much influence overall as well.
With the bleed stack just invert everything below the spacer.
IE
16x0.1
14x0.3
14x0.3 CLAMP
20x1.6 SPACER
Inverted stack
22x0.1x4
20x0.1
18x0.1
16x0.1
14x0.1
11x0.3
11x0.3
bleed ports around post.
This will take the whole bleed stack out of the equation. The 2 11x0.3mm shims won't restrict the bleed at all. The rest of the inverted stack just maintains some height for the stack on the post.
With the bleed stack just invert everything below the spacer.
IE
16x0.1
14x0.3
14x0.3 CLAMP
20x1.6 SPACER
Inverted stack
22x0.1x4
20x0.1
18x0.1
16x0.1
14x0.1
11x0.3
11x0.3
bleed ports around post.
This will take the whole bleed stack out of the equation. The 2 11x0.3mm shims won't restrict the bleed at all. The rest of the inverted stack just maintains some height for the stack on the post.
Just thought I would update this.
Tried a few things and think I have settled on something that I like for now.
Tried the stack as before with the bleed stack flipped.
I had some 0.48 Springs from my KTM which fit but are a little longer equating to 13mm preload.
I found the forks non-compliant at my speeds 2-3rd gear mostly with 0.48 springs, didn't deflect as much as the Marzocchis but not plush or comfortable.
Pulled them down, checked everything.
Seems one of my bushings on the rebound piston is worn and possibly worn the coating on the damper tube
oil was a little grey after a few hrs.
Rebuilt with standard 0.44 springs and fresh Putoline 5wt (22cst).
Took it to a track with MX and enduro loops and bike was almost unrideable. tried clickers and more rebound seemed to help, but not good. Was harsh, wouldn't hold a line but jumped great.....
Back to the bench and found a rebound adjuster rod hiding under a rag lol
Since I was in them again I decided to really soften things and see if I liked them.
Base valves now
4x 32x0.1
22
3x 32
30,28,26,24,22,20,18,16x01,
14x0.3
flipped bleed.
Float 0.4mm in 1 leg 0.3mm in the other (didn't have shims to try 0.35)
Redone everything with ISO15 hydraulic fluid, 15cst to free up the damping a little and its $10 for 5l vs $25 for 2l of fork oil! (also bled my clutch with it and it feels lighter)
Settled with a 0.44 and a 0.48 spring in each leg as didn't have time to revalve before race.
Rode my 1st endurocross and forks preformed really well. No deflection and comfortable.
Is there any way to move the spring perches so preload can be played with?
Was hoping to remove the stop and cut a new groove a bit higher up but cant figure out how to remove the stop without destroying it!
I think id be very happy with my current damping and 0.48 springs with minimal preload.
Yet to try the MX track with this but I can live with some bottoming as id usually be riding enduro and not jumping too big.
Tried a few things and think I have settled on something that I like for now.
Tried the stack as before with the bleed stack flipped.
I had some 0.48 Springs from my KTM which fit but are a little longer equating to 13mm preload.
I found the forks non-compliant at my speeds 2-3rd gear mostly with 0.48 springs, didn't deflect as much as the Marzocchis but not plush or comfortable.
Pulled them down, checked everything.
Seems one of my bushings on the rebound piston is worn and possibly worn the coating on the damper tube
oil was a little grey after a few hrs.Rebuilt with standard 0.44 springs and fresh Putoline 5wt (22cst).
Took it to a track with MX and enduro loops and bike was almost unrideable. tried clickers and more rebound seemed to help, but not good. Was harsh, wouldn't hold a line but jumped great.....
Back to the bench and found a rebound adjuster rod hiding under a rag lol
Since I was in them again I decided to really soften things and see if I liked them.
Base valves now
4x 32x0.1
22
3x 32
30,28,26,24,22,20,18,16x01,
14x0.3
flipped bleed.
Float 0.4mm in 1 leg 0.3mm in the other (didn't have shims to try 0.35)
Redone everything with ISO15 hydraulic fluid, 15cst to free up the damping a little and its $10 for 5l vs $25 for 2l of fork oil! (also bled my clutch with it and it feels lighter)
Settled with a 0.44 and a 0.48 spring in each leg as didn't have time to revalve before race.
Rode my 1st endurocross and forks preformed really well. No deflection and comfortable.
Is there any way to move the spring perches so preload can be played with?
Was hoping to remove the stop and cut a new groove a bit higher up but cant figure out how to remove the stop without destroying it!
I think id be very happy with my current damping and 0.48 springs with minimal preload.
Yet to try the MX track with this but I can live with some bottoming as id usually be riding enduro and not jumping too big.
Zman
Platinum Level Site Supporter
I went through this high preload problem with my YZ SSS forks when the RaceTech springs were too long. I was told by several people in the suspension industry that I should not cut the stock spring perches more than 5mm (to reduce the preload) because that can apply lateral force on the inner chamber fork tube which can dent or bend the tube causing restriction.
While I purchased the race perches to lower the preload more than 5mm, it would have been easier to buy the correct KYB springs that come with the correct length for 5mm of preload.
You can get parts from https://www.suspensiondirect.com/shop/ or http://www.technical-touch.com/
Based upon my spring length problem with RaceTech I will be avoiding them in the future.
While I purchased the race perches to lower the preload more than 5mm, it would have been easier to buy the correct KYB springs that come with the correct length for 5mm of preload.
You can get parts from https://www.suspensiondirect.com/shop/ or http://www.technical-touch.com/
Based upon my spring length problem with RaceTech I will be avoiding them in the future.
I had the old WP springs out of my 950Adv (it got 0.62s) I was hoping to use these to curtail costs (I can get machine work done FOC) but doesn't look straight forward.
I don't want to shave the spring perches as ive read about them damaging the cartridge bodies.
Where did you get the race perches?
Id prefer to move the perch and add spacers vs buy springs as it gives much more scope for trying used springs off ebay etc.
I don't want to shave the spring perches as ive read about them damaging the cartridge bodies.
Where did you get the race perches?
Id prefer to move the perch and add spacers vs buy springs as it gives much more scope for trying used springs off ebay etc.
Zman
Platinum Level Site Supporter
I bought mine from https://www.suspensiondirect.com/shop/
Zman
Platinum Level Site Supporter
I lost some weight and my suspension felt a bit stiff again. I backed out the compression adjusters all the way and it was still a bit stiff. I cut the perches a little more and dropped 2mm from my preload (4mm-ish) and it really softened up the initial feel of the forks. I think I should have done this sooner. I will get a better feel for it this weekend at Loretta Lynns ranch.
Zman
Platinum Level Site Supporter
I rode the first day with about 6 clicks of compression dampening. It was too stiff for the terrain. The forks worked fine for larger bumps but the small trail trash just wore me out over time. I started thinking I am probably getting too old and.... LOL Nope - I just need to get the tune right!
Day 2 I softened the forks by opening the compression clickers all the way with no clicks. I also softened the rear two clicks. That combination worked pretty well but I dont like having the adjuster topped out with no adjustment so I want to have some ability to soften it even more.
These forks came from a YZ450F 2008 or 2009 and I have never changed the ICS pressure springs. I have heard the stock 450 ICS springs could be a little heavy for enduro/trail riding. I order some 1.8 ICS springs from RaceTech.
The install is pretty easy, but I noticed the stock springs are 10mm shorter than the new ones. I read on TT that you don't need to use the plastic spacers with the aftermarket springs, so I tried the install without the spacer. I quickly found out that I could not bleed the inner chamber properly with out the spacer and the rod would not fully extend.
Having 7mm preload or a 5mm gap in the ICS spring did not seem like a good idea so I decided to machine the stock plastic spacer shorter to a total of 9.4mm. This gave me about a 0.5mm gap once it was assembled. The inner chamber bled all the air and the piston extended fully, like normal. It appears that having a bigger ICS spring gap without the spacer is a problem.
When I finished the first fork I compared it side by side (compression by hand) with the fork with the stock ICS spring and the lighter spring feels initially more compliant. Both forks on the bike I could tell it had a softer feel and I needed to add 6 clicks of compression.
We just had our first snow but I will try to sneak out and see how it feels.
Has anyone else changed ICS springs and how did you address the spacer?
Day 2 I softened the forks by opening the compression clickers all the way with no clicks. I also softened the rear two clicks. That combination worked pretty well but I dont like having the adjuster topped out with no adjustment so I want to have some ability to soften it even more.
These forks came from a YZ450F 2008 or 2009 and I have never changed the ICS pressure springs. I have heard the stock 450 ICS springs could be a little heavy for enduro/trail riding. I order some 1.8 ICS springs from RaceTech.
The install is pretty easy, but I noticed the stock springs are 10mm shorter than the new ones. I read on TT that you don't need to use the plastic spacers with the aftermarket springs, so I tried the install without the spacer. I quickly found out that I could not bleed the inner chamber properly with out the spacer and the rod would not fully extend.
Having 7mm preload or a 5mm gap in the ICS spring did not seem like a good idea so I decided to machine the stock plastic spacer shorter to a total of 9.4mm. This gave me about a 0.5mm gap once it was assembled. The inner chamber bled all the air and the piston extended fully, like normal. It appears that having a bigger ICS spring gap without the spacer is a problem.
When I finished the first fork I compared it side by side (compression by hand) with the fork with the stock ICS spring and the lighter spring feels initially more compliant. Both forks on the bike I could tell it had a softer feel and I needed to add 6 clicks of compression.
We just had our first snow but I will try to sneak out and see how it feels.
Has anyone else changed ICS springs and how did you address the spacer?
memphis2857
New member
I have a 2018 with the AOS forks and changed the ICS springs. Stock in them are 2.1 and on advice from a couple different timers I went all the way down to a 1.0. I too freaked a little about the pre-load but a quick call to race tech eased my mind. They said that a little pre-load is actually a good thing and stated it wouldn’t hurt a thing. The springs made a huge difference but a little valving work is still needed. I think the stack needs softened and probably go back up a few rates on the ICS springs.
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