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Factory Connection Suspension Revalve


Owner: thumper_racer
Added on August 09, 2014





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2014 CRF 450 - Suspesnion super harsh in chop



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56 replies to this topic
  • GDI70

    TT Silver Member

805 posts
Location: California

Posted December 21, 2013 - 09:41 AM


 the honda mv is pretty cool for the psf. i also have some other units to test mv configurations. they're from earlier yz125/250.  i got them before the 14's came out, to test with the kx450's. finished the 14 honda this week. we're testing this weekend.

 

there are some other designs for the psf mv out. the other, is a pro circuit unit. it's aluminum, and it does not have a recess in the comp side.  



  • Rmzben

    TT Bronze Member

154 posts
Location: Other

Posted December 22, 2013 - 12:35 PM


 the honda mv is pretty cool for the psf. i also have some other units to test mv configurations. they're from earlier yz125/250.  i got them before the 14's came out, to test with the kx450's. finished the 14 honda this week. we're testing this weekend.

 

there are some other designs for the psf mv out. the other, is a pro circuit unit. it's aluminum, and it does not have a recess in the comp side.  

interesting, I was thinking of trying a procircuit setup on the 14 forks or convert to spring fork. it took me all year to find the best setting on my 13 not sure if I want to waste the year again. whats the valving spec on the 14? is it an improvement or easier to get dialled?



  • GDI70

    TT Silver Member

805 posts
Location: California

Posted December 22, 2013 - 02:19 PM


interesting, I was thinking of trying a procircuit setup on the 14 forks or convert to spring fork. it took me all year to find the best setting on my 13 not sure if I want to waste the year again. whats the valving spec on the 14? is it an improvement or easier to get dialled?


If you have a good setup, then stay with it. The 14 mv pistons should be available soon, if not already. That's the area I would work with on 13 psf forks (kxf/crf).

  • Rmzben

    TT Bronze Member

154 posts
Location: Other

Posted December 22, 2013 - 02:31 PM


If you have a good setup, then stay with it. The 14 mv pistons should be available soon, if not already. That's the area I would work with on 13 psf forks (kxf/crf).

yeah I may even do that! Do you have the standard valving specs of the 14?



  • GDI70

    TT Silver Member

805 posts
Location: California

Posted December 22, 2013 - 02:41 PM


I'll check at shop tomorrow. I should have it somewhere.

  • bearpah

    TT Newbie

11 posts
Location: California

Posted December 23, 2013 - 09:14 PM


So as far as the balance spring goes I need to get a different, I that. But then you started talking about 13's and then I got lost. So, which balance spring do I need to get for the first 111mm of travel. Also, if I am going to get new balance spring - am I going to drop of the factory oil CC's down to 215cc, like they started talking at the beginning and run about 40 PSI?  



  • bearpah

    TT Newbie

11 posts
Location: California

Posted December 23, 2013 - 09:26 PM


GDI70 was also talking about he "Honda MV & PSF MV" - what exactly is that? I went back through the posts and didn't see anything about that…. Also, since I don't quite understand - what would be the Pro Circuit setup that dutto12 is referring to ? 



  • karlace

    TT Silver Member

656 posts
Location: United Kingdom

Posted December 24, 2013 - 02:40 AM


Mv on the 14 bike
4x27.11
24.11
20.11
13.3

  • mx317

    TT Gold Member

1,349 posts
Location: Tennessee

Posted December 24, 2013 - 06:03 AM


GDI70 was also talking about he "Honda MV & PSF MV" - what exactly is that? I went back through the posts and didn't see anything about that…. Also, since I don't quite understand - what would be the Pro Circuit setup that dutto12 is referring to ? 

I know the 14 Honda is supposed to be a single piece mid-valve (MV), while the 13 Honda and 13 and 14 KXF is a two piece MV with large bleed holes. The new Honda valves are supposed to be more like the SDi (suspension Direct) mid-valves except use a regular MV spring.



  • harrperf

    TT Addict

3,391 posts
Location: Texas

Posted December 24, 2013 - 09:38 AM


The new honda MV is one piece, three port.  It still has 2 large bleed holes.

A very simple and easy modification is to plug up one of those bleed holes with epoxy - and for a large deal of riders that's enough change to make huge improvements.

One knock on the PSF is is busy both in compression and rebound.

 



  • wblake

    TT Silver Member

989 posts
Location: Cyprus

Posted December 24, 2013 - 09:44 AM


The new honda MV is one piece, three port.  It still has 2 large bleed holes.

A very simple and easy modification is to plug up one of those bleed holes with epoxy - and for a large deal of riders that's enough change to make huge improvements.

One knock on the PSF is is busy both in compression and rebound.

 

thats a good one!! Ale suggested it to me and with less Float!!

 

am in the process off finding the right amount!! am 0.3 from 0.7 i was before but harshness cripped up!!



  • harrperf

    TT Addict

3,391 posts
Location: Texas

Posted December 24, 2013 - 10:24 AM


It's a fine line to play with, the inlet area on the base valve is also a little different at high speed. 

Lastly it employs a very stiff base valve compared to a conventional fork - with less shim outer diameter the stack is stiffer all around and the base valve is relatively stiff anyways.

You can try keeping the float around .3 but softening the base up some.  Considering the fork is constantly under 30 +psi cavitation is almost a non issue like it is on an ICS fork at full extension.  For that reason the base valve doesn't play as critical a role in making the midvalve function correctly.



  • wblake

    TT Silver Member

989 posts
Location: Cyprus

Posted December 24, 2013 - 10:50 AM


It's a fine line to play with, the inlet area on the base valve is also a little different at high speed. 

Lastly it employs a very stiff base valve compared to a conventional fork - with less shim outer diameter the stack is stiffer all around and the base valve is relatively stiff anyways.

You can try keeping the float around .3 but softening the base up some.  Considering the fork is constantly under 30 +psi cavitation is almost a non issue like it is on an ICS fork at full extension.  For that reason the base valve doesn't play as critical a role in making the midvalve function correctly.

i tried removing a couple off face shims but it seem like it was riding low in the stroke, compromising geometry!! i will check float again before i make any more changes....make sure everything is fine!!

 

i wont get the ofrks back by friday!! which thats keeps things on hold...fair enough though.....its xmas



  • Rmzben

    TT Bronze Member

154 posts
Location: Other

Posted December 24, 2013 - 12:42 PM


This is what I have ended up with which I find to work well. But I still find its soft, hard and harsh all in one.

 

27 x .11 - 3

24 x .11

22 x .11

20 x .11

14 x .11

13 x .3

 

.5 float, epoxy 1 hole, 35 psi, 245ml still experimenting with oil



  • wblake

    TT Silver Member

989 posts
Location: Cyprus

Posted December 24, 2013 - 01:28 PM


This is what I have ended up with which I find to work well. But I still find its soft, hard and harsh all in one.

 

27 x .11 - 3

24 x .11

22 x .11

20 x .11

14 x .11

13 x .3

 

.5 float, epoxy 1 hole, 35 psi, 245ml still experimenting with oil

 

i keep the 18 after the 20 in there, and removed the crossover as well!! but how is you base valve look like?



  • racerfmx450

    TT Silver Member

797 posts
Location: Austria

Posted December 24, 2013 - 02:27 PM


Haha..

Ok cavitation is not a issue on this fork??
You can be sure its more as on all other common forks.
I see oil with lots of air after only 2h of ride.

Ok.
We have always the same preassure inner and outer chartridge .
On all reb. Actions the preassure drops down on in the chamber below the base and above the mid.

Lots of foam and air in the oil...

BTW . I can post.videos if this..

  • GDI70

    TT Silver Member

805 posts
Location: California

Posted December 24, 2013 - 03:23 PM


the fork fluid looks like a milk shake when you empty the cartridges. lol. 

 

what i did for the vet rider was to add a crossover shim 22.11 after three face shims in mid, then added another 27.11 after it.

i left the bleed holes alone. messed with rebound a bit.

i took out the bleed stack altogether, just used two of the 11.25 for spacing.

next, i used a two-staged base valve. the air pressure ended up at 40, and the fluid height was 220cc in the outer tubes.

 

the rider was very happy, and it seemed to go in the direction he had hoped, for the off road terrain he used the bike in. we ran clickers at 12c 14r

the bike stayed up in the stroke very well. looking forward to the mx testing with the larger mammal. 

 

i have another rider to do some testing with the earlier yz mv pistons next week. i only drilled one bleed hole in those pistons #56 bit. i want to play with some different float heights and stack tapers.

 

the next thing i'd like to do is test the psf on a two-smoker. replacing the 05 yamaha forks. (i prefer the 05 shock). i want to try to make a woods weapon out of that bike, but i'd like to see how the two stroke mx would work as well. with the two smokers coming back in competition.



  • Rmzben

    TT Bronze Member

154 posts
Location: Other

Posted December 24, 2013 - 03:32 PM


i keep the 18 after the 20 in there, and removed the crossover as well!! but how is you base valve look like?

 

just looked at my note book its actually .45 float. I was running the 18 in there but with the float at .45 it was pretty harsh on highspeed. its similar to a dave j setup i have seen. also my base is different to standard not sure if its the best base setup. and my rebound is a lot different to which I found to be a big problem especially after epoxy hole up!



  • wblake

    TT Silver Member

989 posts
Location: Cyprus

Posted December 24, 2013 - 04:09 PM


the fork fluid looks like a milk shake when you empty the cartridges. lol. 

 

what i did for the vet rider was to add a crossover shim 22.11 after three face shims in mid, then added another 27.11 after it.

i left the bleed holes alone. messed with rebound a bit.

i took out the bleed stack altogether, just used two of the 11.25 for spacing.

next, i used a two-staged base valve. the air pressure ended up at 40, and the fluid height was 220cc in the outer tubes.

 

the rider was very happy, and it seemed to go in the direction he had hoped, for the off road terrain he used the bike in. we ran clickers at 12c 14r

the bike stayed up in the stroke very well. looking forward to the mx testing with the larger mammal. 

 

i have another rider to do some testing with the earlier yz mv pistons next week. i only drilled one bleed hole in those pistons #56 bit. i want to play with some different float heights and stack tapers.

 

the next thing i'd like to do is test the psf on a two-smoker. replacing the 05 yamaha forks. (i prefer the 05 shock). i want to try to make a woods weapon out of that bike, but i'd like to see how the two stroke mx would work as well. with the two smokers coming back in competition.

Marc, when you say stack tapers...are you reffering to the shims below the clamp?

 

i used different OD shims to keep the xmas tree taper before the clamp!! i wonder if that effects the shim stack stiffness...and if it would be better to place them before the last OEM shims to keep the original taper in there with alter float height...!!

 

just looked at my note book its actually .45 float. I was running the 18 in there but with the float at .45 it was pretty harsh on highspeed. its similar to a dave j setup i have seen. also my base is different to standard not sure if its the best base setup. and my rebound is a lot different to which I found to be a big problem especially after epoxy hole up!

i used to run 0.7 float with stock reb and comp except the croosover removed! 2.4,200ml oil.....no major problems except...some harshness..or rather lack of plushness!!! it was raceable, but we went for more plushness and oped up a can of worms with 0.3 float...last time!!.....am going to check everything again on friday to check i did do something wrong and maybe open float a bit more!!



  • Rmzben

    TT Bronze Member

154 posts
Location: Other

Posted December 24, 2013 - 04:17 PM


Marc, when you say stack tapers...are you reffering to the shims below the clamp?

 

i used different OD shims to keep the xmas tree taper before the clamp!! i wonder if that effects the shim stack stiffness...and if it would be better to place them before the last OEM shims to keep the original taper in there with alter float height...!!

 

i used to run 0.7 float with stock reb and comp except the croosover removed! 2.4,200ml oil.....no major problems except...some harshness..or rather lack of plushness!!! it was raceable, but we went for more plushness and oped up a can of worms with 0.3 float...last time!!.....am going to check everything again on friday to check i did do something wrong and maybe open float a bit more!!

 

haha yeah I tried .30 aswell, things got pretty wild up front but it ploughed through sx whoops!







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