i've been diving into the suspension on my 17 250 xc ..... this is by far the best info on Ut00b about how forks work ..... i have gold valves on my AER forks, and i just put the JBI subvalve on it to mimic the SSS valve, and i really like it, just road it once but it's better than before ... just put a racetech bladder on the shock and revalved it, got too cheap to buy the gold valve, tho probably should have .... thanks for the great info, i gotta read some more ....
Awesome video with tons of info. I’ve heard good things about the JBI pro perch and the Enzo Technica spring tube upgrades. Do you have any insight on these? And also is the gold valve only needed for the compression not on the rebound?
Hey these are great videos? Can you clarify if I have a 2021 yz250f that has the pistons drilled from factory can I still remove the top oring for less friction? Or best not to? Thanks for the videos!
What impact do the pressure springs have on feel? Should a lighter one be used for a different type of terrain, like really rocky, slow single track, or for a lighter rider ?
The pressure or reservoir springs are there to manage fluid consistency and prevent the possibility of cavitation. The spring pressure combined with compression damping force should always be stronger than midvalve force in order to ensure absolute stability. Given the tendency for a lot of tuners to seek more and more from the mid without consideration of this fact tends to lead to trouble....making the spring lighter excaserbates the problem. Its the same as letting gas pressure out of your shock. I have never yet replaced a pressure spring with a lighter one.
Thank you again for your great videos. I may be stupid but i still dont understand when you should change damping on the base valve or the compression side of the mid valve. I cant find any videos or anything that explains this either. Also having float on the mid valve does not make any sense to me either.
That's ok. It seems a lot of tuners face this same dilemma. Oil has to move to the back of the mid as a matter of priority. This is necessary to promote maximum oil stability. This is required for maximum damping performance and quality outcomes. The float provides this ability as it offers very little resistance to initial fluid movement building its force after this has happened. The trampoline set up does not. Having no float makes absolutely no sense in fluid dynamics. We often make the mistake of giving factories too much credit. It is very easy to make the SSS work so much better than what the factory has provided......
Hey Terry....Jlo here from So Cal (you used to tune my suspension when I lived in Aus back in the early 2000s). Fantastic videos you've been putting up on youtube!! Keep up the amazing suspension clinics! Wish I still lived there, could use your help with a few bikes I've got (R1 track bike, 1290 Superduke street bike, Husky FS450 Supermoto Bike and Husky 501 desert sled). Maybe I fly you up here for a little one on one tuning!?!? Cheers, keep up the great informative work!
The correlation that he was referring to is the mid valve float to the base valve bleed shims. The standard mid valve float is .25 and it makes for a smooth initial stroke. This adds confidence for traction and slow speed movement.
At around 15:16, a cartridge is mentioned but I couldn't make out the name. Delsol GSV? Would love to know the proper name of the referenced cartridge so I can research them. Thanks in advance and thanks for this video.
HI Many thanks for your nice video, since you are so knowledgeable about the kyb forks i have a question. I gave my forks for service for my VFR1200F & when i got it back the rebound adjuster has play moving up & down now. When i adjusted it i noticed it moving by about 2mm down. I would ride a bit & it would pop out again. To add to the issue i have fully seated the adjuster just to get rebound on the forks. What could be wrong? Thanks!!
There may not be anything wrong apart from the fact that you may not like this anomaly. The outer screw is often engaged in the lower adjusting mechanism via a flat tab into a slotted grub screw. It is the grub screw that ultimately determines the position of the rebound rod, not the external screw. If pressure builds within the fork tube (which it will) it may pop the outer screw back a little but the internal grub screw will remain in position. The outer screw is sealed by an o-ring. If this o-ring loses a bit of tension, the screw can move a little. This movement is of little consequence.
Hello Brian from Canada , I am running Gold valves in my 18 yz250f along with the separator valve in the rear , which I believe is your design . Maybe you could talk about that . Also what brands of fork fluid do you recommend . Thanks
Why change the trampoline valve to a spring? I’m sure it depends on application and correct me if I’m wrong, but changing the float by shim stack height on the leaf or trampoline valve seems to have more adjustment range than changing to a spring. As for the compression piston why not just use thicker shims? Best regards from Portugal!
Firstly, due to the preload involved with the trampoline..."float" is not an accurate description. We are trying to initiate flow through the mid as a priority. Given the sheer fluid volume the mid sees compared to that of the base, resistance here has a far greater effect. The spring and actual float creates a better feel and greater stability. There really is no greater adjustability with the trampoline beyond preload and this to me is an unwanted scenario....so why would you want it? If you can find a benefit, I am keen to hear it. As for the thicker shims.....that's just a variation on stack thickness. The villian here is area, port growth rate and discharge velocity. You certainly can beef up the stack to increase velocity but growth rate remains the same resulting in poor stroke control. Once again, the moment of inertia involved in stack opening is still greater than what is ideal and in fact, made worse with a heavier stack. Not every new idea is a technical innovation and the trampoline is another attempt to offer a compensation for the loss of stroke control presented by such large port pistons. Unfortunately it is very difficult to get suspension people away from suspension theories and back to the underlying laws of hydraulics and fluid dynamics.
Basically the level of damping generated vs the level of damping required. Sometimes you may find that the amount of damping is fine but the balance between low speed and high speed is skewed which will affect traction and control
Not a fair comparison......The WP is a nice alternative to stock but the design brief of the Dal Soggio was always going to make it that much better. I still prefer the CC bladder fork over anything that WP have produced so far. Dal Soggio have taken that concept to the extreme with better materials, force values and coatings.
If I buy your cartridge, and valve....du you include recommended shimstack for diffrent terrain? Or is this all for stock shimstack? Cheers from Sweden
We customise each setting. Our valving is generally based around rider weight, discipline and skill level. You will find that there is enough range in the adjusting circuits to accommodate various types of terrain.
My 2021 kyb fork have also free play in the ics spring an the rod wont fully extend the ics spring lenght 90mm with 15mm spacer from kyb do i need to ad an extra spacer ?
That model had enough preload on the spring standard, but that doesn't mean that the spring could not have "sacked out" a little, reducing it's length. Alternatively if the bike was purchased second hand and you don't know the full history, it may have an aftermarket option in there. If either is the case, then a spacer could be installed. Prior to this I would explore the following options.....Is there a slight leak from either the lower cartridge seal or ICS seal? Also is there noticable friction between the damper rod and the lower cartridge seal which could inhibit full extension?
The bike is new its a fantic 250xx model 2023 the forks are the old model not from the fourstroke al seal’s in the ics and cartridge are new when i bleed the system the final step a little oil air escapes after this i compress the rod full it wont fully extend no more the ics piston spring have a little free play after that but no air in the cartridge
On a lighter 2-stroke (YZ125) would it be beneficial to experiment with a smaller diameter 24mm restrictor stack ? (my initial G2R instructions suggested a 26mm)
I wouldn't. The matching of port areas means that the mid and the base ramp up at the same rate in order to maintain consistency. You can simply adjust your shimstack.
@@shocktreatment5495 Thanks for the reply. I'm not too far off on the shimstack. Curious if since I had purchased these G2R valves back in 2014 if the latest recommended settings had since changes.
@@michellatour150 If you wish to email me your settings along with your rider details, I would be happy to make a recommendation for you. We use these valves more than anyone else worldwide and have some great settings.
@@shocktreatment5495 Thank you very much for the offer, I'll dig up the infos of the original Race Tech recommendations and, the settings that I've finally settled on after many many experiments. Merci!
Ooh. I have this one on my 21 yz450.... Awsome video...do you sell parts and ship to Sweden? I just ordered 1spring (just on 1 side)1 rate higher from stock to try stop it dive in breaking Cheers from Sweden
The stock springs are quite firm already. The dive is generally attributed to the valve port growth rate. If you have a local distributor of Race Tech products, you could simply order the valve through them. I would be happy to assist you with set up details.
@@shocktreatment5495 I could order from race tech but iam interested in your fork öeg and total setup. I will email you when its time and see what we can do. Thank you. Cheers from Sweden
The Showa forks actually have a better build quality than KYB but few people will judge a fork on how it is built. Most will judge it on how it feels. This comes down to the selection of shimstacks and springs. (tuning). I would happily own a Showa fork as it is very easy to tune it for a better outcome than what comes standard from the factory.
@@shocktreatment5495 I don’t know about the inner build of each fork just the feel of every KYB bike I’ve ridden. I do know showas respond more to clicker adjustments
The drawback with the SSS is the pressure system. It provides an unwanted element to the fork movement. You can simply take each cartridge and compress them (out of the fork). The difference is staggering. I did a video comparing initial movement requirement between a WP CC cartridge and the KYB SSS. You can see it on our facebook page. The KYB takes 4 times as much force to get a similar response to the WP
Weird, I've never liked the feel of the mod setup you describe and have found suspension nirvana with stock valves and unconventional valving. To each their own...
You can have 10 guys ride the same bike. 7 might love it, 2 are on the fence and 1 hates it. It doesn't make anyone wrong, it just highlights the fact that people are different. Any set up is merely one of several million possible configurations. If you didn't like one setting....you are judging the force not the product. Technically, the stock valve is poo.
@@shocktreatment5495 If the stock valves are crap how come all the factory teams with showa and KYB factory suspension aren't running RT valves? All the A kit and factory stuff that I know of is running stock style valves or something really close. Those stock valves have fairly small port entrances, so it's not as dramatic as you make it.
@@chrisgall4664 I think you are giving too much credit to some of these teams. There are better people working in the backs of shops than out of the backs of semis. You too could be a factory mechanic if you are prepared to be exploited and give up most of your weekends. Its a high turnover occupation. I prefer to take my cues from science rather than teams. KYB, Showa, WP "are" all using RT style valves. It was Paul Thede who led the way and all the companies have beaten a path to high flow pistons. However rather than pay RT, they made their own pistons using this very concept.....they just took it too far. You need to give up on the unfettered belief and just question for a minute. Why make a 35mm piston and use a large clamp shim to shut the port area down? Kind of counter-intuitive.....but highly indicative that the area is too great. But don't believe me, look for yourself.
Problem with OEM forks is that they internal dampener rod diameter is to small and does not move enough volume of oil into the upper chamber to really make the BV tunable and 110% usefully. But them look at the factory forks.....Larger outer diameter tubes allow for larger inner cartlidge which then have more oil volume and use of larger diameter dampener rod which translates into more volume of oil displaced into the upper chamber a lot more tunable BV as more oil is forced into the Upper chamber. * Dont bother with the GV's they are GARABGE....I have coffee cans full of them from riders that we sold the snake oil of RT's GV's
How many factory forks have larger cartridges? The 52s from WP are the largest and the cartridges are no bigger. Why do you struggle with a gold valve........That makes no sense and only demonstrates a lack of understanding of displacement over area. It's simple hydraulic ratio. It's just maths....simple maths.
@@shocktreatment5495 I have had 2 sets of factory only Showa's.....both had 16 mm inner dampener (OEM IS 12MM) rods and BV's that had 24mm face shims...LSV was also larger shims as well as the BV Chamber being longer and larger. BV piston took 32mm face shims
@@dogger2186 Well I must say I have never seen a 16mm rod in any of the A kit gear I have worked with......but I have seen Showa copy the Gold Valve flat out. Particularly in their "A kit gear". This is hardly surprising. At one time nearly every technician at Showa USA came from RT with Scott Bennet heading up the team. The current stock Showas have hailed from the A kit design with their "14mm" rod and 39mm comp piston which is simply an expansion on RT thinking. Nearly every suspension company in the world has taken a leaf out of the RT playbook when it comes to valve design....I don't know why you struggle with the concept. If you know more than the guys at Showa you should send in a resume
Superb video. Thanks, Terry - really helpful in explaining how the cartridge system works & can be improved.
The way you explain suspension is so easy to under stand , thank you
i've been diving into the suspension on my 17 250 xc ..... this is by far the best info on Ut00b about how forks work ..... i have gold valves on my AER forks, and i just put the JBI subvalve on it to mimic the SSS valve, and i really like it, just road it once but it's better than before ... just put a racetech bladder on the shock and revalved it, got too cheap to buy the gold valve, tho probably should have .... thanks for the great info, i gotta read some more ....
Love the thought process, good stuff.
Awesome video with tons of info. I’ve heard good things about the JBI pro perch and the Enzo Technica spring tube upgrades. Do you have any insight on these? And also is the gold valve only needed for the compression not on the rebound?
really interesting! will be nice if you can make similar video for the wp 4860cc. great contents :)
That will be our next video
Another awesome and education vid, thank you.
Great video Terry, very informative !
Glad you enjoyed it
Hey these are great videos? Can you clarify if I have a 2021 yz250f that has the pistons drilled from factory can I still remove the top oring for less friction? Or best not to? Thanks for the videos!
What impact do the pressure springs have on feel? Should a lighter one be used for a different type of terrain, like really rocky, slow single track, or for a lighter rider ?
The pressure or reservoir springs are there to manage fluid consistency and prevent the possibility of cavitation. The spring pressure combined with compression damping force should always be stronger than midvalve force in order to ensure absolute stability. Given the tendency for a lot of tuners to seek more and more from the mid without consideration of this fact tends to lead to trouble....making the spring lighter excaserbates the problem.
Its the same as letting gas pressure out of your shock. I have never yet replaced a pressure spring with a lighter one.
@@shocktreatment5495 Thank you very much for the detailed response. 👍
Thank you again for your great videos. I may be stupid but i still dont understand when you should change damping on the base valve or the compression side of the mid valve. I cant find any videos or anything that explains this either. Also having float on the mid valve does not make any sense to me either.
That's ok. It seems a lot of tuners face this same dilemma. Oil has to move to the back of the mid as a matter of priority. This is necessary to promote maximum oil stability. This is required for maximum damping performance and quality outcomes. The float provides this ability as it offers very little resistance to initial fluid movement building its force after this has happened. The trampoline set up does not. Having no float makes absolutely no sense in fluid dynamics. We often make the mistake of giving factories too much credit. It is very easy to make the SSS work so much better than what the factory has provided......
great video ver interesting
Hey Terry....Jlo here from So Cal (you used to tune my suspension when I lived in Aus back in the early 2000s). Fantastic videos you've been putting up on youtube!! Keep up the amazing suspension clinics! Wish I still lived there, could use your help with a few bikes I've got (R1 track bike, 1290 Superduke street bike, Husky FS450 Supermoto Bike and Husky 501 desert sled). Maybe I fly you up here for a little one on one tuning!?!?
Cheers, keep up the great informative work!
Still don't miss The Finke though!
Hey, How are you Big Fella? Book the flight and line up the beers....I'll bring my tools.
Do you use a thicker oil to combat the large piston flow? If so what oilwt do you recommend?
@@garywiant6543 No we use 5wt and utilise the shimstack to limit the flow
Whats normal float for mid valve have do same to base valve. Need change shim stack match or should just make small bumps softer?
The correlation that he was referring to is the mid valve float to the base valve bleed shims. The standard mid valve float is .25 and it makes for a smooth initial stroke. This adds confidence for traction and slow speed movement.
At around 15:16, a cartridge is mentioned but I couldn't make out the name. Delsol GSV? Would love to know the proper name of the referenced cartridge so I can research them. Thanks in advance and thanks for this video.
Dal Soggio
HI Many thanks for your nice video, since you are so knowledgeable about the kyb forks i have a question. I gave my forks for service for my VFR1200F & when i got it back the rebound adjuster has play moving up & down now. When i adjusted it i noticed it moving by about 2mm down. I would ride a bit & it would pop out again. To add to the issue i have fully seated the adjuster just to get rebound on the forks. What could be wrong? Thanks!!
There may not be anything wrong apart from the fact that you may not like this anomaly. The outer screw is often engaged in the lower adjusting mechanism via a flat tab into a slotted grub screw. It is the grub screw that ultimately determines the position of the rebound rod, not the external screw. If pressure builds within the fork tube (which it will) it may pop the outer screw back a little but the internal grub screw will remain in position. The outer screw is sealed by an o-ring. If this o-ring loses a bit of tension, the screw can move a little. This movement is of little consequence.
Hello Brian from Canada , I am running Gold valves in my 18 yz250f along with the separator valve in the rear , which I believe is your design . Maybe you could talk about that . Also what brands of fork fluid do you recommend . Thanks
No worries
Why change the trampoline valve to a spring? I’m sure it depends on application and correct me if I’m wrong, but changing the float by shim stack height on the leaf or trampoline valve seems to have more adjustment range than changing to a spring. As for the compression piston why not just use thicker shims?
Best regards from Portugal!
Firstly, due to the preload involved with the trampoline..."float" is not an accurate description. We are trying to initiate flow through the mid as a priority. Given the sheer fluid volume the mid sees compared to that of the base, resistance here has a far greater effect. The spring and actual float creates a better feel and greater stability. There really is no greater adjustability with the trampoline beyond preload and this to me is an unwanted scenario....so why would you want it? If you can find a benefit, I am keen to hear it.
As for the thicker shims.....that's just a variation on stack thickness. The villian here is area, port growth rate and discharge velocity. You certainly can beef up the stack to increase velocity but growth rate remains the same resulting in poor stroke control. Once again, the moment of inertia involved in stack opening is still greater than what is ideal and in fact, made worse with a heavier stack. Not every new idea is a technical innovation and the trampoline is another attempt to offer a compensation for the loss of stroke control presented by such large port pistons. Unfortunately it is very difficult to get suspension people away from suspension theories and back to the underlying laws of hydraulics and fluid dynamics.
Hi Terry, when you say the latest rebound settings are a little questionable, are you able to enlighten us by what you mean by this?
Cheers 🍻
Basically the level of damping generated vs the level of damping required. Sometimes you may find that the amount of damping is fine but the balance between low speed and high speed is skewed which will affect traction and control
Hi Terry, excellent video. How do you rate the Delsogio Sphere V WP 6500 ?
Not a fair comparison......The WP is a nice alternative to stock but the design brief of the Dal Soggio was always going to make it that much better. I still prefer the CC bladder fork over anything that WP have produced so far. Dal Soggio have taken that concept to the extreme with better materials, force values and coatings.
@@shocktreatment5495 Would love to see next some info on Shocks: Pistons, Bladders/Free Piston and High Speed Adjusters etc
If I buy your cartridge, and valve....du you include recommended shimstack for diffrent terrain?
Or is this all for stock shimstack?
Cheers from Sweden
We customise each setting. Our valving is generally based around rider weight, discipline and skill level. You will find that there is enough range in the adjusting circuits to accommodate various types of terrain.
So with that free piston I can do away with the top oring? For better feel and less friction.
Also really enjoy your videos.
Yes
My 2021 kyb fork have also free play in the ics spring an the rod wont fully extend the ics spring lenght 90mm with 15mm spacer from kyb do i need to ad an extra spacer ?
That model had enough preload on the spring standard, but that doesn't mean that the spring could not have "sacked out" a little, reducing it's length. Alternatively if the bike was purchased second hand and you don't know the full history, it may have an aftermarket option in there. If either is the case, then a spacer could be installed. Prior to this I would explore the following options.....Is there a slight leak from either the lower cartridge seal or ICS seal? Also is there noticable friction between the damper rod and the lower cartridge seal which could inhibit full extension?
The bike is new its a fantic 250xx model 2023 the forks are the old model not from the fourstroke al seal’s in the ics and cartridge are new when i bleed the system the final step a little oil air escapes after this i compress the rod full it wont fully extend no more the ics piston spring have a little free play after that but no air in the cartridge
On a lighter 2-stroke (YZ125) would it be beneficial to experiment with a smaller diameter 24mm restrictor stack ? (my initial G2R instructions suggested a 26mm)
I wouldn't. The matching of port areas means that the mid and the base ramp up at the same rate in order to maintain consistency. You can simply adjust your shimstack.
@@shocktreatment5495 Thanks for the reply. I'm not too far off on the shimstack. Curious if since I had purchased these G2R valves back in 2014 if the latest recommended settings had since changes.
@@michellatour150 If you wish to email me your settings along with your rider details, I would be happy to make a recommendation for you. We use these valves more than anyone else worldwide and have some great settings.
@@shocktreatment5495 Thank you very much for the offer, I'll dig up the infos of the original Race Tech recommendations and, the settings that I've finally settled on after many many experiments. Merci!
Ooh. I have this one on my 21 yz450....
Awsome video...do you sell parts and ship to Sweden?
I just ordered 1spring (just on 1 side)1 rate higher from stock to try stop it dive in breaking
Cheers from Sweden
The stock springs are quite firm already. The dive is generally attributed to the valve port growth rate. If you have a local distributor of Race Tech products, you could simply order the valve through them. I would be happy to assist you with set up details.
@@shocktreatment5495 thank you for the answer...I already ordered the spring so i will try it just to know.
@@shocktreatment5495 I could order from race tech but iam interested in your fork öeg and total setup.
I will email you when its time and see what we can do.
Thank you.
Cheers from Sweden
What is the difference to a Showa fork. Every KYB component has been superior and plusher to me in my experience 🤷♂️
The Showa forks actually have a better build quality than KYB but few people will judge a fork on how it is built. Most will judge it on how it feels. This comes down to the selection of shimstacks and springs. (tuning). I would happily own a Showa fork as it is very easy to tune it for a better outcome than what comes standard from the factory.
@@shocktreatment5495 I don’t know about the inner build of each fork just the feel of every KYB bike I’ve ridden. I do know showas respond more to clicker adjustments
What would it take for you to get the same level of performance as the Dal Soggio Spheres?
The drawback with the SSS is the pressure system. It provides an unwanted element to the fork movement. You can simply take each cartridge and compress them (out of the fork). The difference is staggering. I did a video comparing initial movement requirement between a WP CC cartridge and the KYB SSS. You can see it on our facebook page. The KYB takes 4 times as much force to get a similar response to the WP
When did they do away with the MV float?
When they introduced the trampoline style midvalve....a few years now
@@shocktreatment5495 I need to understand what that looks like.
@@mann277 Pull a set apart. Its quite interesting
Weird, I've never liked the feel of the mod setup you describe and have found suspension nirvana with stock valves and unconventional valving. To each their own...
You can have 10 guys ride the same bike. 7 might love it, 2 are on the fence and 1 hates it. It doesn't make anyone wrong, it just highlights the fact that people are different. Any set up is merely one of several million possible configurations. If you didn't like one setting....you are judging the force not the product. Technically, the stock valve is poo.
@@shocktreatment5495 If the stock valves are crap how come all the factory teams with showa and KYB factory suspension aren't running RT valves? All the A kit and factory stuff that I know of is running stock style valves or something really close. Those stock valves have fairly small port entrances, so it's not as dramatic as you make it.
@@chrisgall4664 I think you are giving too much credit to some of these teams. There are better people working in the backs of shops than out of the backs of semis. You too could be a factory mechanic if you are prepared to be exploited and give up most of your weekends. Its a high turnover occupation. I prefer to take my cues from science rather than teams. KYB, Showa, WP "are" all using RT style valves. It was Paul Thede who led the way and all the companies have beaten a path to high flow pistons. However rather than pay RT, they made their own pistons using this very concept.....they just took it too far.
You need to give up on the unfettered belief and just question for a minute. Why make a 35mm piston and use a large clamp shim to shut the port area down? Kind of counter-intuitive.....but highly indicative that the area is too great. But don't believe me, look for yourself.
Problem with OEM forks is that they internal dampener rod diameter is to small and does not move enough volume of oil into the upper chamber to really make the BV tunable and 110% usefully. But them look at the factory forks.....Larger outer diameter tubes allow for larger inner cartlidge which then have more oil volume and use of larger diameter dampener rod which translates into more volume of oil displaced into the upper chamber a lot more tunable BV as more oil is forced into the Upper chamber.
* Dont bother with the GV's they are GARABGE....I have coffee cans full of them from riders that we sold the snake oil of RT's GV's
How many factory forks have larger cartridges? The 52s from WP are the largest and the cartridges are no bigger. Why do you struggle with a gold valve........That makes no sense and only demonstrates a lack of understanding of displacement over area. It's simple hydraulic ratio. It's just maths....simple maths.
@@shocktreatment5495 I have had 2 sets of factory only Showa's.....both had 16 mm inner dampener (OEM IS 12MM) rods and BV's that had 24mm face shims...LSV was also larger shims as well as the BV Chamber being longer and larger. BV piston took 32mm face shims
@@dogger2186 Well I must say I have never seen a 16mm rod in any of the A kit gear I have worked with......but I have seen Showa copy the Gold Valve flat out. Particularly in their "A kit gear". This is hardly surprising. At one time nearly every technician at Showa USA came from RT with Scott Bennet heading up the team. The current stock Showas have hailed from the A kit design with their "14mm" rod and 39mm comp piston which is simply an expansion on RT thinking.
Nearly every suspension company in the world has taken a leaf out of the RT playbook when it comes to valve design....I don't know why you struggle with the concept. If you know more than the guys at Showa you should send in a resume
I believe kyb couldn't vent the piston due to a showa patent ?