80 replies to this topic

[suhoi27 TT Bronze Member]

I am also interested in enduro applications!...As for the retrofit: I was able to put a Cone Valve kit into my WP CC fork  with almost 0 issues and some little modifications. So Far so Good ,however the REB stack has some bleed shim which gives me a headaches!...Kit part number is: R14000...It is said that "it will not work on any OEM WP CC,OC,SXS...only WP Factory fork".....Well, it works on WP CC-how good compared to the Original -I have no idea?!

[Drehwurm TT Silver Member]

Well, the list is just that - a mere listing of the WP part #s which could be used for a conversion-project IF the parts would be available. The parts are in no way intended by WP to be used in any of their other forks and a conversion takes a lot of tinkering.

For the rebound, stock is the following:

14 x 0.25
11 x 0.30
12 x 0.15
14 x 0.15
16 x 0.10
T20 x 0.10
12 x 0.10
3xT20 x 0.10
16 x 0.10

but I feel the 16x.1 bleed causes some low speed rebound issues. That's what I'm running albeit with heavily modified pistons and and non-standard rebound check valve on the BV:

d18x.10
(3) d20x.10
10x.10
d18x.10
16x.10
14x.10
12x.10
10x.25
12x.10
16x.25

d or T designates delta shims.

Michael

[suhoi27 TT Bronze Member]

Good info,Michael! Thank you!....In my case,Franken fork, this bleed shim causes both dive and LS REB issues...the fork feels sooo loose ..As a result bike becomes very unstable during high speed (130km/h +),gravel or lightly bumped roads...I will follow you REB idea and report!

The same fork,with OEM CV RB Stack was awesome on my 07 300 EXCE,though! However Big 4T puts much more different requirements into this equation.

[Drehwurm TT Silver Member]

I assume you run a CV setup with some float. IMO the relatively high, moveable mass of the cone is prone for resonance issues if being able to float freely without spring tension. Might be as well that this is just what is happening at such high speeds with your forks. Because of that and I don't like the feel of free float on the CV in general all my setups have either 0 float/preload (offroad) or some preload on the CV spring for MX. Just my 2 cent.

FWIW I think that the retrofitted CV setups don't really exploit the best traits of the CV concept which actually start where a traditional mid valve setup sees its limits already. For this to happen though you need some serious cartridge pressue which is difficult to achieve with the 28mm BV pistons of the standard WP CC bladder forks. The original CV fork uses a copy of the 23/24mm MV piston on the BV. But then you might run into cavitation problems as the bladder setup gets to its limits. Just some food for your thoughts ...

Michael

[suhoi27 TT Bronze Member]

You are absolutely right, Michael ! While the retrofit worked perfectly on my 2T, on 500 EXC  it showed the drawbacks you have described-any of them! You know me-I am "just do it" person and since I did it, I can say you are right!
Trying to run 0 float led to severe air/oil flow through the cart. seal and rising the bladder pressure to around 50 psi didn't solve the problem.
As for the cone resonance at 0.2mm float: I discovered a specific speed and terrain where this was quite an evident-There were some 1+ secs. delays or unexpected fork's performance. I thought that CV assembly was loose, I checked it and it was just fine.

As a matter of fact I tried 20N CV spring with 0.1ish preload: Better performance,but nothing to compare with my 2T awesome experience.
My thinking is that big 4T engine (torque, eng. compression.and braking) puts quite a different longitudinal moments over the suspension and any suspension's issue becomes easily "visible"- Husaberg 570 was a great (and expensive) lesson.

To sum up: this 400 Euro CV retrofit worked perfectly on 2T and for this amount of money was well worth it!....
On 4T?!...Well, I am looking to buy an original CV fork-any offer is welcome!...I am just afraid not to buy some "Netherlands made" fork:)!

[suhoi27 TT Bronze Member]

Just came from testing Michael's REB stack- Definitely much better and planted feedback, however couldn't get rid of this pronounced   Low Speed Springy performance. I fell down few times during some very technical ride over some fallen trees and bike speed around 5km/h:)..It was like a spring elevator:)

Anyway, this retrofit ain't gonna work for my 4T bike. I'd love to buy some original Cone Valve fork. Any enduro oriented feedback is urgently needed.

[yamaha227 TT Silver Member]

suhoi27, on 27 April 2012 - 08:49 AM, said:

Just came from testing Michael's REB stack- Definitely much better and planted feedback, however couldn't get rid of this pronounced   Low Speed Springy performance. I fell down few times during some very technical ride over some fallen trees and bike speed around 5km/h:)..It was like a spring elevator:)

Anyway, this retrofit ain't gonna work for my 4T bike. I'd love to buy some original Cone Valve fork. Any enduro oriented feedback is urgently needed.

Tried the DFMV yet?

[suhoi27 TT Bronze Member]

Yes! Working on it. I actually have 2 sets cartridges and just swap them:)

[yamaha227 TT Silver Member]

suhoi27, on 29 April 2012 - 08:42 PM, said:

Yes! Working on it. I actually have 2 sets cartridges and just swap them:)

Sounds good. Keen to know how you get on.

[KTM-Lew TT Titanium Member]

yamaha227, on 29 April 2012 - 02:58 PM, said:

Tried the DFMV yet?

DFMV being what?

[ds1434 TT Silver Member]

KTM-Lew, on 30 April 2012 - 06:05 AM, said:

DFMV being what?

I'm assuming it's the same as the new KYB midvalve setup used on the 11kxf's and 12 crf's correct?(450's)
There's a set of 11 kxf(450) on fleabay for 700 that I almost pulled the trigger on to see how that particular setup feels.

[Adammoto TT Silver Member]

ds1434, on 30 April 2012 - 01:54 PM, said:

I'm assuming it's the same as the new KYB midvalve setup used on the 11kxf's and 12 crf's correct?(450's)
There's a set of 11 kxf(450) on fleabay for 700 that I almost pulled the trigger on to see how that particular setup feels.

The Dynamic Float Midvalve (DFMV) is my adaptation of this design for WP forks.  It's not the same - but it's the same idea.

[ds1434 TT Silver Member]

Well that's cool !!
So does your design not use as much limit for the stack?

[Vietze TT Silver Member]

Adammoto, on 30 April 2012 - 08:52 PM, said:

The Dynamic Float Midvalve (DFMV) is my adaptation of this design for WP forks.  It's not the same - but it's the same idea.

I would love to see a picture of that design!

[Adammoto TT Silver Member]

ds1434, on 01 May 2012 - 03:55 AM, said:

Well that's cool !!
So does your design not use as much limit for the stack?

It's a highly stressed MV.  Generally .3-.5 mm static float with .8 mm dynamic float.  There are some other internal differences including no slide collar and a 9mm tapered pivot.  My primary application is offroad.

[KTM-Lew TT Titanium Member]

Adammoto, on 01 May 2012 - 06:07 AM, said:

It's a highly stressed MV.  Generally .3-.5 mm static float with .8 mm dynamic float.  There are some other internal differences including no slide collar and a 9mm tapered pivot.  My primary application is offroad.

Sounds like MX-Tech's SCMV?

[Adammoto TT Silver Member]

KTM-Lew, on 01 May 2012 - 12:40 PM, said:

Sounds like MX-Tech's SCMV?

I don't think so.  Correct me if I'm wrong - but I believe Jeremy's MV uses an 8mm pivot and no dynamic float feature.  Both designs use lower float values, but functionally they are quite different.  The DFMV can be tuned to have a lot more blowoff - useful for offroad but probably unnecessary for motocross.

[CrobarGreg TT Member]

Hey guys I hate to high jack the thread . I have a pair of cv forks on my Ktm. Skf seals.  Do your cv forks like to weep small amounts of oil? My just wet the tubes a little.  I want to know if this is normal for cv forks.

[yamaha227 TT Silver Member]

CrobarGreg, on 24 May 2013 - 03:20 PM, said:

Hey guys I hate to high jack the thread . I have a pair of cv forks on my Ktm. Skf seals.  Do your cv forks like to weep small amounts of oil? My just wet the tubes a little.  I want to know if this is normal for cv forks.

A mate of mine has 2 sets, set for his practice bike and a set for his race bike. He seems to be for ever getting leaking seals... So maybe its a common thing??

[CrobarGreg TT Member]

Ok thanks