2003 fork feel compared to 2022 - how close can a revalve get me?

mark_swart
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mark_swart
Edited Date/Time 10/20/2022 10:55am
I have a 2003 YZ 125 I’m building for AHRMA Millennium class racing. The spring rate is correct for me, but what feels so different compared to my modern bike is that they just seem to blow through the mid stroke - this is really most noticeable during heavy braking. Landings really aren’t an issue. I don’t want to do an SSS conversion because of class rules. Do any of you suspension gurus think that a revalve would get me that more progressive feel of a modern fork, or are there design limitations in the older one that would prevent it? Thanks in advance!
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Bruce372
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Bruce372 12/20/2021 1:11pm
12/20/2021 1:11pm
I think they are the open cartridge forks like the 2001? They ran a big midvalve float and the trick was to reduce it down a bit.

Also, I think there was a kind of valve at the cartridge seal that could be sacked out... Best bet is call Enzo. They ran high oil levels and substanks
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skypig
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skypig 12/20/2021 2:18pm
12/20/2021 2:18pm
I had a 2004 YZ250F. The local guy removed the “bleed valve” and waved his wand over the valving - a huge improvement.
At my pace (slow), the 2008 SSS, also valved by the same guy, I upgraded to, wasn’t noticeably better.
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UGOTBIT
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UGOTBIT 12/20/2021 3:03pm
12/20/2021 3:03pm
The KYB 46U's have issues like you mentioned.

Like Bruce said, the mid needs work and the cartridge valve is also an issue.

I went the RaceTech route on mine and could not get them working like I wanted, they kept blowing through the stroke. Played with oil height, added sub tanks, researched deleting the cartridge valve, talked to Dave J at Smart performance on setting up the mid, ect. RaceTech had no midvalve settings and were not much help as things progressed.

If you want to keep them I would have Enzo set them up, probably with a set of sub tanks. They can rework the midvalve and delete the cartridge valve and get them working much better I'm sure.

What exactly are the class rules regarding suspension?
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mark_swart
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mark_swart 12/21/2021 6:18am
12/21/2021 6:18am
UGOTBIT wrote:
The KYB 46U's have issues like you mentioned. Like Bruce said, the mid needs work and the cartridge valve is also an issue. I went the...
The KYB 46U's have issues like you mentioned.

Like Bruce said, the mid needs work and the cartridge valve is also an issue.

I went the RaceTech route on mine and could not get them working like I wanted, they kept blowing through the stroke. Played with oil height, added sub tanks, researched deleting the cartridge valve, talked to Dave J at Smart performance on setting up the mid, ect. RaceTech had no midvalve settings and were not much help as things progressed.

If you want to keep them I would have Enzo set them up, probably with a set of sub tanks. They can rework the midvalve and delete the cartridge valve and get them working much better I'm sure.

What exactly are the class rules regarding suspension?
Thanks for all that info!! As far as class rules, really the way I read it is that it just can't be SSS. I probably can't justify investing in a full Enzo setup, but your observations saves me from going down the RT rabbit hole.

I'll probably try to add some oil to see if that gets me close enough. I'm also using the bike as a regular rider and practice bike.
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FGR01
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FGR01 12/21/2021 6:23am
12/21/2021 6:23am
Yes those forks can be made pretty good. I recall riding some really nice KYB 46's as far back as 94-95 YZ250.

Good call on raising the oil level. The nice thing is you can use a syringe and add 5-10cc at a time in each leg through the bleed hole until you get the bottoming resistance you want.
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JB500
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JB500 12/21/2021 12:30pm
12/21/2021 12:30pm Edited Date/Time 12/21/2021 12:31pm
UGOTBIT wrote:
The KYB 46U's have issues like you mentioned. Like Bruce said, the mid needs work and the cartridge valve is also an issue. I went the...
The KYB 46U's have issues like you mentioned.

Like Bruce said, the mid needs work and the cartridge valve is also an issue.

I went the RaceTech route on mine and could not get them working like I wanted, they kept blowing through the stroke. Played with oil height, added sub tanks, researched deleting the cartridge valve, talked to Dave J at Smart performance on setting up the mid, ect. RaceTech had no midvalve settings and were not much help as things progressed.

If you want to keep them I would have Enzo set them up, probably with a set of sub tanks. They can rework the midvalve and delete the cartridge valve and get them working much better I'm sure.

What exactly are the class rules regarding suspension?
mark_swart wrote:
Thanks for all that info!! As far as class rules, really the way I read it is that it just can't be SSS. I probably can't...
Thanks for all that info!! As far as class rules, really the way I read it is that it just can't be SSS. I probably can't justify investing in a full Enzo setup, but your observations saves me from going down the RT rabbit hole.

I'll probably try to add some oil to see if that gets me close enough. I'm also using the bike as a regular rider and practice bike.
Mark - I have an 03 YZ 125 and use it now as my main race bike. I'm 37 years old, 165lbs fast B rider, only ride motocross. I had my local Pro Action guy revalve mine for my weight 2 seasons ago, as stock springs were OK. I was having a bit of that mid-harsh feel you are talking about - EDIT: even after the revalve - and I couldn't get it out with just clicker adjustments. When I changed oil and seals this past winter, I added 10 CC's, and ended up being able to go softer on my clickers and still maintain the bottoming resistance - It actually feels better. Going softer on my compression settings seems to have helped the mid stroke harshness I was getting on small chop style bumps. It's not as good as the SSS feel on the newer bikes, but man, it's not far off as you'd think. If you are anywhere near my weight and riding style, I'd be happy to send you the settings I'm running.
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UGOTBIT
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UGOTBIT 12/21/2021 1:53pm
12/21/2021 1:53pm
If I was to try these again I would go right after the midvalve, it's the major source of the problem. The cartridge valve can be disabled/blocked off, RaceTech makes a kit to do this, but it adds sticktion and can be done without it. I'll post info Terry Hay gave me on this, he actually made a new top for the cartridge to delete it, but no longer makes it.

I may be wrong, but I remember in my research something about the cartridge/rod size not being ideal and getting a good setting can be hard on the shims permanently distorting them quickly.

Another option could be 2004 forks, they are 48mm open chambers, people speak highly of them.
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mark_swart
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mark_swart 12/21/2021 2:03pm
12/21/2021 2:03pm
UGOTBIT wrote:
The KYB 46U's have issues like you mentioned. Like Bruce said, the mid needs work and the cartridge valve is also an issue. I went the...
The KYB 46U's have issues like you mentioned.

Like Bruce said, the mid needs work and the cartridge valve is also an issue.

I went the RaceTech route on mine and could not get them working like I wanted, they kept blowing through the stroke. Played with oil height, added sub tanks, researched deleting the cartridge valve, talked to Dave J at Smart performance on setting up the mid, ect. RaceTech had no midvalve settings and were not much help as things progressed.

If you want to keep them I would have Enzo set them up, probably with a set of sub tanks. They can rework the midvalve and delete the cartridge valve and get them working much better I'm sure.

What exactly are the class rules regarding suspension?
mark_swart wrote:
Thanks for all that info!! As far as class rules, really the way I read it is that it just can't be SSS. I probably can't...
Thanks for all that info!! As far as class rules, really the way I read it is that it just can't be SSS. I probably can't justify investing in a full Enzo setup, but your observations saves me from going down the RT rabbit hole.

I'll probably try to add some oil to see if that gets me close enough. I'm also using the bike as a regular rider and practice bike.
JB500 wrote:
Mark - I have an 03 YZ 125 and use it now as my main race bike. I'm 37 years old, 165lbs fast B rider, only...
Mark - I have an 03 YZ 125 and use it now as my main race bike. I'm 37 years old, 165lbs fast B rider, only ride motocross. I had my local Pro Action guy revalve mine for my weight 2 seasons ago, as stock springs were OK. I was having a bit of that mid-harsh feel you are talking about - EDIT: even after the revalve - and I couldn't get it out with just clicker adjustments. When I changed oil and seals this past winter, I added 10 CC's, and ended up being able to go softer on my clickers and still maintain the bottoming resistance - It actually feels better. Going softer on my compression settings seems to have helped the mid stroke harshness I was getting on small chop style bumps. It's not as good as the SSS feel on the newer bikes, but man, it's not far off as you'd think. If you are anywhere near my weight and riding style, I'd be happy to send you the settings I'm running.
I’d definitely be interested in your settings- I’m 49, same weight, also B (at least for my age group!)
Bruce372
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Bruce372 12/21/2021 5:18pm
12/21/2021 5:18pm
UGOTBIT wrote:
[img]https://p.vitalmx.com/photos/forums/2021/12/21/524026/s1200_1F21DB49_1C90_4AEF_8284_C79227E4BE11.jpg[/img] [img]https://p.vitalmx.com/photos/forums/2021/12/21/524027/s1200_AFA9454D_B951_422B_828C_A239AF2A05B6.jpg[/img] [img]https://p.vitalmx.com/photos/forums/2021/12/21/524028/s1200_C36857DB_17FC_46AB_AA2A_96EDEDFA0343.jpg[/img]



I actually had an unused set of these I sold on here a couple of years ago that had been sat in my parts bin for over 17 years
UGOTBIT
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UGOTBIT 12/21/2021 5:43pm
12/21/2021 5:43pm
Bruce372 wrote:
I actually had an unused set of these I sold on here a couple of years ago that had been sat in my parts bin for...
I actually had an unused set of these I sold on here a couple of years ago that had been sat in my parts bin for over 17 years
I think that picture is yours, I came across it and tried to buy them a few years back but was too late lol
JB500
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JB500 12/21/2021 6:00pm
12/21/2021 6:00pm
mark_swart wrote:
Thanks for all that info!! As far as class rules, really the way I read it is that it just can't be SSS. I probably can't...
Thanks for all that info!! As far as class rules, really the way I read it is that it just can't be SSS. I probably can't justify investing in a full Enzo setup, but your observations saves me from going down the RT rabbit hole.

I'll probably try to add some oil to see if that gets me close enough. I'm also using the bike as a regular rider and practice bike.
JB500 wrote:
Mark - I have an 03 YZ 125 and use it now as my main race bike. I'm 37 years old, 165lbs fast B rider, only...
Mark - I have an 03 YZ 125 and use it now as my main race bike. I'm 37 years old, 165lbs fast B rider, only ride motocross. I had my local Pro Action guy revalve mine for my weight 2 seasons ago, as stock springs were OK. I was having a bit of that mid-harsh feel you are talking about - EDIT: even after the revalve - and I couldn't get it out with just clicker adjustments. When I changed oil and seals this past winter, I added 10 CC's, and ended up being able to go softer on my clickers and still maintain the bottoming resistance - It actually feels better. Going softer on my compression settings seems to have helped the mid stroke harshness I was getting on small chop style bumps. It's not as good as the SSS feel on the newer bikes, but man, it's not far off as you'd think. If you are anywhere near my weight and riding style, I'd be happy to send you the settings I'm running.
mark_swart wrote:
I’d definitely be interested in your settings- I’m 49, same weight, also B (at least for my age group!)
PM sent.
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mark_swart
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mark_swart 1/16/2022 9:05am
1/16/2022 9:05am
JB500 wrote:
Mark - I have an 03 YZ 125 and use it now as my main race bike. I'm 37 years old, 165lbs fast B rider, only...
Mark - I have an 03 YZ 125 and use it now as my main race bike. I'm 37 years old, 165lbs fast B rider, only ride motocross. I had my local Pro Action guy revalve mine for my weight 2 seasons ago, as stock springs were OK. I was having a bit of that mid-harsh feel you are talking about - EDIT: even after the revalve - and I couldn't get it out with just clicker adjustments. When I changed oil and seals this past winter, I added 10 CC's, and ended up being able to go softer on my clickers and still maintain the bottoming resistance - It actually feels better. Going softer on my compression settings seems to have helped the mid stroke harshness I was getting on small chop style bumps. It's not as good as the SSS feel on the newer bikes, but man, it's not far off as you'd think. If you are anywhere near my weight and riding style, I'd be happy to send you the settings I'm running.
mark_swart wrote:
I’d definitely be interested in your settings- I’m 49, same weight, also B (at least for my age group!)
JB500 wrote:
PM sent.
I had my first ride with the added oil yesterday (90mm), they actually felt worlds better! It kept it from diving so much during braking, which was my main gripe. They may not feel as good as the forks on my modern bike, but they are definitely good enough that I doubt I'll be doing anything else to them. Thanks again, I would have never thought to go that high but it does the trick!

Yesterday's Ride Video:
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kijen
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kijen 1/16/2022 9:35am
1/16/2022 9:35am
Had a 2003 yz250, factory connection had a very good set up,
JB500
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JB500 1/20/2022 4:01am
1/20/2022 4:01am
mark_swart wrote:
I’d definitely be interested in your settings- I’m 49, same weight, also B (at least for my age group!)
JB500 wrote:
PM sent.
mark_swart wrote:
I had my first ride with the added oil yesterday (90mm), they actually felt worlds better! It kept it from diving so much during braking, which...
I had my first ride with the added oil yesterday (90mm), they actually felt worlds better! It kept it from diving so much during braking, which was my main gripe. They may not feel as good as the forks on my modern bike, but they are definitely good enough that I doubt I'll be doing anything else to them. Thanks again, I would have never thought to go that high but it does the trick!

Yesterday's Ride Video:
Mark, that is great to hear, thanks for posting back with an update.
Skerby
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Skerby 1/20/2022 9:45am
1/20/2022 9:45am
I rode a set of 46s with sub tanks, they were as good as my SSS at the time. Comparing an 01 YZ250 to an 09 YZ250 so not apples to apples but pretty close.
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m21racing
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m21racing 1/21/2022 8:06am
1/21/2022 8:06am
Skerby wrote:
I rode a set of 46s with sub tanks, they were as good as my SSS at the time. Comparing an 01 YZ250 to an 09...
I rode a set of 46s with sub tanks, they were as good as my SSS at the time. Comparing an 01 YZ250 to an 09 YZ250 so not apples to apples but pretty close.
Funny how well you can get an old set of oc forks to work. The 46mm '96 honda cr250 forks were my fav. The shocks of that vintage were fine, and can be tuned.
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sandhills
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sandhills 7/16/2022 8:19am
7/16/2022 8:19am
Reviving this thread to ask for any more info about this black magic.

I have only worked on 03 and 04 forks so I am only familiar with cartridges with this rubber seal. I notice it does add stiction, I tore it apart hoping a cartridge bushing and piston ring was going to solve this stiction only to find this rubber causing it.

Is this rubber seal not present on newer fork designs?

What did KYB think it should do that tuners decided was unnecessary? Is it just that the bushing actually provides sufficient seal on its own?

Couldn't the rubber simply be cut out with an exacto knife?
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FWYT 10/20/2022 10:55am
10/20/2022 10:55am
sandhills wrote:
Reviving this thread to ask for any more info about this black magic. I have only worked on 03 and 04 forks so I am only...
Reviving this thread to ask for any more info about this black magic.

I have only worked on 03 and 04 forks so I am only familiar with cartridges with this rubber seal. I notice it does add stiction, I tore it apart hoping a cartridge bushing and piston ring was going to solve this stiction only to find this rubber causing it.

Is this rubber seal not present on newer fork designs?

What did KYB think it should do that tuners decided was unnecessary? Is it just that the bushing actually provides sufficient seal on its own?

Couldn't the rubber simply be cut out with an exacto knife?
Bumping this thread because I am interested, too!Smile

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