Has Anyone Tried These ZETA KYB AOS Pistons Yet?

Related:
Create New Tag

twotwosix

Vital MX member twotwosix
54416 twotwosix http://p.vitalmx.com/photos/users/54416/avatar/c50_manners171_1505055582.jpg?1505055463 http://www.vitalmx.com/community/twotwosix,54416/all 09/29/16 63 1131 9

Posts: 1194

Joined: 9/29/2016

Location: TN, USA

9/27/2017 1:35 PM
Edited Date/Time: 9/27/2017 1:39 PM

These caught my eye. Curious if anyone has experience yet using these as a drop in replacement? Only $60. I know the plastic pistons are prone to breaking. They offer a standard replacement, as well as a LT version...

FREE PISTON for KYB AOS (Twin chamber) front forks.

ZE56-40012 LT Light weight and less friction design, provides soften and smooth front fork moving.

http://www.zeta-racing.com/sus/freepiston/index.html



Born in Corona, living in East TN.

mx317

Vital MX member mx317
3927 mx317 http://p.vitalmx.com/photos/users/3927/avatar/c50_IMG_0758_1476807303.jpg?1476807256 http://www.vitalmx.com/community/mx317,3927/all 04/01/08 5 http://www.vitalmx.com/community/mx317,3927/setup 51 2123 5

Posts: 2174

Joined: 4/1/2008

Location: TN, USA

9/27/2017 1:40 PM

They look nice, but I haven't used them. I split the std ones on my 2012 KX450F.

Take it to the limit, one more time!

Derek Harris

Vital MX member Derek Harris
48008 Derek Harris http://p.vitalmx.com/photos/users/48008/avatar/c50_Screenshot_92_1436233938.jpg?1436233803 http://www.vitalmx.com/community/Derek-Harris,48008/all 07/06/15 1 2 240

Posts: 242

Joined: 7/6/2015

Location: USA

9/27/2017 2:25 PM

They work same as the other metal pistons on the market at a cheaper price point.

I suggest the "plush" version or whatever they call it not because of that... rather because kyb screwed up and didn't allow the upper chamber of ics to be equalized to atmosphere stock. Showas clone of the sss found on the Crf250r 2010 had this bleed screw (FYI)

adam8781

Vital MX member adam8781
50033 adam8781 http://p.vitalmx.com/photos/users/50033/avatar/c50_11800243_10154046585496416_2865429292532496487_n_1450806541.jpg?1450806368 http://www.vitalmx.com/community/adam8781,50033/all 12/22/15 11 351

Posts: 362

Joined: 12/22/2015

Location: CAN

9/27/2017 9:57 PM

cut the oring groove off the plastic ones and drill the sides out, they are indestructible after that

smezmx

Vital MX member smezmx
20478 smezmx http://p.vitalmx.com/photos/users/20478/avatar/c50_image_1453890080.jpg?1453890021 http://www.vitalmx.com/community/smezmx,20478/all 05/25/10 3 12 http://www.vitalmx.com/community/smezmx,20478/setup 45 1692 43 3

Posts: 1737

Joined: 5/25/2010

Location: Bexley,kent,england., GBR

9/28/2017 5:00 AM
Edited Date/Time: 9/28/2017 5:01 AM

These fork caps look "nice" from zeta too but can't seem to find them in the uk ?





montesagold

Vital MX member montesagold
17427 montesagold http://p.vitalmx.com/photos/users/17427/avatar/c50_95883760_1274956460.jpg?1294193482 http://www.vitalmx.com/community/montesagold,17427/all 10/15/09 2 41 509 7 1

Posts: 550

Joined: 10/15/2009

Location: East, TN USA

9/28/2017 6:56 AM

who sales zeta stuff? I've seen a few of their products but wasn't sure if they were legit or not, now these look really good

Derek Harris

Vital MX member Derek Harris
48008 Derek Harris http://p.vitalmx.com/photos/users/48008/avatar/c50_Screenshot_92_1436233938.jpg?1436233803 http://www.vitalmx.com/community/Derek-Harris,48008/all 07/06/15 1 2 240

Posts: 242

Joined: 7/6/2015

Location: USA

9/28/2017 7:00 AM

adam8781 wrote:

cut the oring groove off the plastic ones and drill the sides out, they are indestructible after that

Far from true.

I've seen plenty stil break. It's an enigma but they still do it.

slipdog

Vital MX member slipdog
16124 slipdog http://p.vitalmx.com/photos/users/16124/avatar/c50_Screenshot_2017_11_10_at_4.28.33_AM_1510439790.jpg?1510438986 http://www.vitalmx.com/community/slipdog,16124/all 07/25/09 9 1 31 7194 57 9

Posts: 7225

Joined: 7/25/2009

Location: Nor Cal, CA USA

9/28/2017 7:22 AM

adam8781 wrote:

cut the oring groove off the plastic ones and drill the sides out, they are indestructible after that

Derek Harris wrote:

Far from true.

I've seen plenty stil break. It's an enigma but they still do it.

I have also seen a handful over the years that had the the ridge of the lower bushing groove broken off. I can't say for sure, but I think it may be from excessive rocking because it was always on a free piston with the upper o ring removed.

twotwosix

Vital MX member twotwosix
54416 twotwosix http://p.vitalmx.com/photos/users/54416/avatar/c50_manners171_1505055582.jpg?1505055463 http://www.vitalmx.com/community/twotwosix,54416/all 09/29/16 63 1131 9

Posts: 1194

Joined: 9/29/2016

Location: TN, USA

9/28/2017 8:19 AM

montesagold wrote:

who sales zeta stuff? I've seen a few of their products but wasn't sure if they were legit or not, now these look really good

Zeta is distributed in the US by Western Powersports, so most any reputable dealership or retailer should have their items. Zeta is pretty high quality at a lower price point. I have a few trinkets of theirs on my bike.

Born in Corona, living in East TN.

twotwosix

Vital MX member twotwosix
54416 twotwosix http://p.vitalmx.com/photos/users/54416/avatar/c50_manners171_1505055582.jpg?1505055463 http://www.vitalmx.com/community/twotwosix,54416/all 09/29/16 63 1131 9

Posts: 1194

Joined: 9/29/2016

Location: TN, USA

9/28/2017 8:20 AM

Derek Harris wrote:

They work same as the other metal pistons on the market at a cheaper price point.

I suggest the "plush" version or whatever they call it not because of that... rather because kyb screwed up and didn't allow the upper chamber of ics to be equalized to atmosphere stock. Showas clone of the sss found on the Crf250r 2010 had this bleed screw (FYI)

Do you think the plush pistons would be an improvement for Motocross?

Born in Corona, living in East TN.

Radical

Vital MX member Radical
35968 Radical http://p.vitalmx.com/photos/users/35968/avatar/c50_2011_09_03_13_12_35_990_1368338813.jpg?1368338588 http://www.vitalmx.com/community/Radical,35968/all 10/20/12 1 4 1183 9

Posts: 1187

Joined: 10/20/2012

Location: San Diego, CA USA

9/28/2017 11:06 AM
Edited Date/Time: 9/28/2017 9:27 PM

I've been looking at them for my YZ125.
I'll be going for the solid ones with both O-rings.

It's hard to believe that KYB would leave the pistons solid without the relief holes for 12 years, if having the piston solid wasn't for a reason. I'd really like to know that reason.

They have to be aware of the pistons exploding. Is the free piston the cheap part that prevents more expensive damage?

Is it solid for performance reasons?

What do they recommend? Holes or no holes, solid or open? 0-rings or no o-rings?

If anyone has a contact from KYB engineering that can answer these questions it would make it a lot easier to choose a free piston replacement.

And of lesser importance:
Why are the pistons open on some bikes, but solid on SSS? Is the solid piston a part of what makes SSS great?

There was a thread on this a while back with some suspension guys including ML chiming in.
I appreciate the feedback, and that drilling the holes mostly prevents the pistons from exploding, but it would be great to know from KYB what they recommend on the question above and why.

Have a great day!
Radical

Derek Harris

Vital MX member Derek Harris
48008 Derek Harris http://p.vitalmx.com/photos/users/48008/avatar/c50_Screenshot_92_1436233938.jpg?1436233803 http://www.vitalmx.com/community/Derek-Harris,48008/all 07/06/15 1 2 240

Posts: 242

Joined: 7/6/2015

Location: USA

9/28/2017 11:59 AM

Radical wrote:

I've been looking at them for my YZ125.
I'll be going for the solid ones with both O-rings.

It's hard to believe that KYB would leave the pistons solid without the relief holes for 12 years, if having the piston solid wasn't for a reason. I'd really like to know that reason.

They have to be aware of the pistons exploding. Is the free piston the cheap part that prevents more expensive damage?

Is it solid for performance reasons?

What do they recommend? Holes or no holes, solid or open? 0-rings or no o-rings?

If anyone has a contact from KYB engineering that can answer these questions it would make it a lot easier to choose a free piston replacement.

And of lesser importance:
Why are the pistons open on some bikes, but solid on SSS? Is the solid piston a part of what makes SSS great?

There was a thread on this a while back with some suspension guys including ML chiming in.
I appreciate the feedback, and that drilling the holes mostly prevents the pistons from exploding, but it would be great to know from KYB what they recommend on the question above and why.

Have a great day!
Radical

Your getting too far into the thought process.

Most people can NOT tell a difference from a drilled set to an std set.

The SSS was sold on a host of bikes - Thank MXA for mis marketing it as exclusive to yamaha. Honda 450 in 09-last year before air fork had them
kawasaki 450 had them through 2012 i think starting in 06 but certainly in 09 was identical design as yamaha had.

I see a lot of enzo forks with the ICS pistons drilled....take it for what you want - they work closely with kyb

KYB really screwed up by NOT allowing a bleed hole for the ICS air space that is sealed in the piston. If pressure does somehow build up whether its temperature rise - or leakage of pressure from outer chamber etc...it can not be bled. Also - if you take a non drilled SSS fork from sea level to altitude - the pressure in the ICS chamber will be much higher than intended.

Showa's first clone of the SSS that came on the 10 crf250 (and I do mean clone - through and through) had two bleed screws. One for the outer chamber - one for the ICS chamber. As they adopted a "drilled" style design this went away. The bleed screw is a smart and IMHO necessary addition to a sealed ics chamber.


Ultimately many people (including a host of shops) do not understand what the ICS springs influence actually is on a fork - or what varied pressure/spring rate will have on it. The difference in pressure on the top side of the ICS chamber when it's drilled and not drilled is not drastically different except when close to bottomed. The first 2/3 of the stroke drilled vs non drilled is nearly identical.

Mr. Robinson

Vital MX member Mr. Robinson
42138 Mr. Robinson http://p.vitalmx.com/photos/users/42138/avatar/c50_FG_604_2T_1464676833.jpg?1464675946 http://www.vitalmx.com/community/Mr-Robinson,42138/all 02/13/14 1 4 212 11 1

Posts: 216

Joined: 2/13/2014

Location: IN, USA

9/28/2017 4:02 PM

I'm using them. Just as nice as the ones that cost over double that.

Get them from Langston's Motorsports.

Radical

Vital MX member Radical
35968 Radical http://p.vitalmx.com/photos/users/35968/avatar/c50_2011_09_03_13_12_35_990_1368338813.jpg?1368338588 http://www.vitalmx.com/community/Radical,35968/all 10/20/12 1 4 1183 9

Posts: 1187

Joined: 10/20/2012

Location: San Diego, CA USA

9/28/2017 9:43 PM

Radical wrote:

I've been looking at them for my YZ125.
I'll be going for the solid ones with both O-rings.

It's hard to believe that KYB would leave the pistons solid without the relief holes for 12 years, if having the piston solid wasn't for a reason. I'd really like to know that reason.

They have to be aware of the pistons exploding. Is the free piston the cheap part that prevents more expensive damage?

Is it solid for performance reasons?

What do they recommend? Holes or no holes, solid or open? 0-rings or no o-rings?

If anyone has a contact from KYB engineering that can answer these questions it would make it a lot easier to choose a free piston replacement.

And of lesser importance:
Why are the pistons open on some bikes, but solid on SSS? Is the solid piston a part of what makes SSS great?

There was a thread on this a while back with some suspension guys including ML chiming in.
I appreciate the feedback, and that drilling the holes mostly prevents the pistons from exploding, but it would be great to know from KYB what they recommend on the question above and why.

Have a great day!
Radical

Derek Harris wrote:

Your getting too far into the thought process.

Most people can NOT tell a difference from a drilled set to an std set.

The SSS was sold on a host of bikes - Thank MXA for mis marketing it as exclusive to yamaha. Honda 450 in 09-last year before air fork had them
kawasaki 450 had them through 2012 i think starting in 06 but certainly in 09 was identical design as yamaha had.

I see a lot of enzo forks with the ICS pistons drilled....take it for what you want - they work closely with kyb

KYB really screwed up by NOT allowing a bleed hole for the ICS air space that is sealed in the piston. If pressure does somehow build up whether its temperature rise - or leakage of pressure from outer chamber etc...it can not be bled. Also - if you take a non drilled SSS fork from sea level to altitude - the pressure in the ICS chamber will be much higher than intended.

Showa's first clone of the SSS that came on the 10 crf250 (and I do mean clone - through and through) had two bleed screws. One for the outer chamber - one for the ICS chamber. As they adopted a "drilled" style design this went away. The bleed screw is a smart and IMHO necessary addition to a sealed ics chamber.


Ultimately many people (including a host of shops) do not understand what the ICS springs influence actually is on a fork - or what varied pressure/spring rate will have on it. The difference in pressure on the top side of the ICS chamber when it's drilled and not drilled is not drastically different except when close to bottomed. The first 2/3 of the stroke drilled vs non drilled is nearly identical.

Thanks Derek!

So, it makes sense that bottoming may be slightly harsher with the open piston and missing top o-ring, but not really (or so slight that it doesn't matter) with the bleed holes drilled in the plastic piston.

With the open piston or with holes drilled, does fork oil make it's way where it normally wouldn't?

It could be many things, but I did notice a difference with my forks after the broken plastic piston was replaced with an open one, and the other plastic piston drilled. I can't really say what's different, just that it's not better.

I think suspension will be the next thing for me to really learn about.
It's difficult to ride and know what to change.
It's going to take some time.

Thanks again

JBecker 72

Vital MX member JBecker 72
42627 JBecker 72 http://p.vitalmx.com/photos/users/42627/avatar/c50_joe_dirt_david_spade_1402778055.jpg?1402777122 http://www.vitalmx.com/community/JBecker-72,42627/all 03/25/14 8 539 1 1

Posts: 547

Joined: 3/25/2014

Location: Manassas, VA USA

9/29/2017 9:13 AM

I broke the ones in my 13 YZ250 and had them replaced with new stock ones when my suspension was done last winter. I believe they were drilled by my suspension guy, but not positive. If it happens again I will give these a try.

mx_phreek

Vital MX member mx_phreek
17303 mx_phreek http://p.vitalmx.com/photos/users/17303/avatar/c50_94724070_1293893912.jpg?1294193329 http://www.vitalmx.com/community/mx-phreek,17303/all 10/07/09 1 21 727 60

Posts: 748

Joined: 10/7/2009

Location: Manchester, GBR

9/29/2017 10:19 AM

Don't you see a lot of this stuff on the bikes in Japan they race?

bvm111

Vital MX member bvm111
10841 bvm111 http://p.vitalmx.com/photos/users/10841/avatar/c50_IMG_1291_1490419411.jpg?1490419386 http://www.vitalmx.com/community/bvm111,10841/all 07/01/08 1 1 17 5576 34 3

Posts: 5593

Joined: 7/1/2008

Location: Las Vegas, NV USA

9/29/2017 10:33 AM

I have my OEM pistons drilled and have not had an issue with them breaking... yet. Unfortunately these alloy ones don't seem to be available for my 06 KX250, evidently there is a difference between the 450 and 250 two stroke forks.

I also have small spacers installed between the spring and base that removes the slop from the piston allowing for easier bleeding of the IC and it seems to work well for the past few years. Has anyone else done this modification and what have your results been?

Never try to argue with idiots; they will only bring you down to their level.....and being more experienced, they will beat you at their own game!

2016 KX450f
2006 KX250

711mx

Vital MX member 711mx
41446 711mx http://p.vitalmx.com/photos/users/41446/avatar/c50_20131222_131404_1387749412.jpg?1387748504 http://www.vitalmx.com/community/711mx,41446/all 12/22/13 5 31

Posts: 36

Joined: 12/22/2013

Location: GBR

9/29/2017 11:04 AM

smezmx wrote:

These fork caps look "nice" from zeta too but can't seem to find them in the uk ?





They are available, Madison import them and are available through any Zeta dealer

Underground

Vital MX member Underground
19904 Underground http://p.vitalmx.com/photos/users/19904/avatar/c50_Lawrence_and_Osbourne_1506860407.jpg?1506859631 http://www.vitalmx.com/community/Underground,19904/all 04/11/10 56 2571 41

Posts: 2627

Joined: 4/11/2010

Location: ATA

9/29/2017 1:52 PM

I'm no expert on this issue or done thousands of them but I've always thought it was due people not putting in the correct inner chamber fork oil quantity, either too little or too much with then not bleeding off the excess that bypasses the piston and draining from the top chamber. I always go a tad more than pump the rod the full stroke several times, listening for air trapped in the lower chamber and ensure that the pressure build up by the spring when fully compressed will fully extend the rod out again by it's own or near to it. Then I turn up and ensure all the excess oil is drained out of the top air bleed. Worked for me so far anyway.
My theory is oil trapped above the piston lessens the air volume for the piston displacement and when the fork takes a big bottom, there is a greater air pressure rise above the piston than the plastic piston can handle and the air bleed can release. It could be cyclic failure or it could be a sudden failure I don't know.
Just my 2 cents.

Underground

Vital MX member Underground
19904 Underground http://p.vitalmx.com/photos/users/19904/avatar/c50_Lawrence_and_Osbourne_1506860407.jpg?1506859631 http://www.vitalmx.com/community/Underground,19904/all 04/11/10 56 2571 41

Posts: 2627

Joined: 4/11/2010

Location: ATA

9/29/2017 1:53 PM

Zeta make some nice stuff too. Way better quality than a lot of the cheap junk out there these days.