KYB twin chambers

[fnengineer]

Terry,

I am going to be servicing a set of 05 forks and I was hoping I could bug you for a bit. Possibly looking for an upgrade kit like you described earlier. My email is mx174@hotmail.com

thanks

Mike

 

[bedell99]

Now that this thread is back, I have a question is anybody making aftermarket ICS springs that are longer. I would think that would be a hot seller.

Erik

 

[James]

very informative Terry.
Thank you
Where do you drill the 4mm hole in the piston?

I have read this thread 8 times and I still don't see a clear answer on this.

I understand the taper on the base-valve post part of this fix. Is there an additional hole that needs to be drilled in the PVC piston? Should it be on the side of the piston with the intention of creating a path to the outer chamber?

 

[Zenith]

Sorry to revive this old thread, but I have a quick question before I rebuild my 05 YZ125 forks if somebody could help me out.

I've put an 8mm spacer above the ICS spring and bled the cartridge (125mm oil level and bleed at 45 degree angle as mop suggested), the rod extends all the way out now so all seems good. I didn't drill/taper the adjuster post as the cartridge seemed to bleed OK without it.

My question is on the main spring spacer though. What size is good here? I believe the springs are negatively preloaded 5mm stock. I've put a 9mm spacer (so effectively 4mm preload on the spring) in to one of the forks and rebuilt it, but not being familiar with fork preload I thought I should check if 4mm was OK before going on with the second fork and going riding tomorrow. I feel I could do with a bit of extra preload anyway as I'm on the heavy side of the recommended weight for these springs. But not knowing what sort of preload figures are "normal" I don't know if 4mm is WAY to much, not enough or perfect.
Even if somebody could tell me some typical preload numbers I'd know if I'm way off or not...

Thanks for any thoughts!

 

[marcusgunby]

Philip its hard to say whats the right amount of preload, i think some showas come with as little as 3mm and others more like 10mm(the 05 crf i think has alot of preload) i would start at something like 4mm as its got bto be better than -5mm.

 

[steve125]

Phillip, I set mine at + 3mm and it works real well. If you go to far it may effect your turning. I think thats why Yamaha set it negative in the first place.

 

[Zenith]

Went with 4mm as this was the size of my spacer (which was an outer race of a CR125 wheel bearing LOL).
I'm not the best at noticing changes in suspension, but I rode today and the forks seemed much improved, none of the unusual 'effects' I was having when riding before. Not sure what made the main difference but for the record I went with 8mm spacer on the ICS, bleed hole not drilled, bled as per mop's instructions (got full rod extension this way, cheers mop!), 9mm spacer on the main spring, 245ml oil level. I put in a set of Synergy seals as well, should be interesting to see how they go. Bit of a pain to install, but once I'd done one it was easier.

Anybody know if similar things apply to the 06 version of these forks, specifically the ones on the YZ125?

 

[Zenith]

Nobody knows if the 06 is similar or does nobody care anymore? :)

 

[yam 3]

i think the 06's are "new and improved"

 

[anca]

When I rebuilt the forks ( ‘05 YZ250F ), I installed the spacer in ICS, bleeding as mop advised ( full rod extension like Zenith ), no piston drilling or rod modification, no spacers for the main spring. The result was a more predictable front, better cornering, but still pushing, and it became harsh. I checked the fork travel and it seems that it’s not using the last 20mm. I tried all the clicker combination, even with the air bleeding screws out. Still 20mm not used, with the screws out it became more plush but still it’s not like it was before.
The oil is Ohlins, 245ml, 5wt in the ICS (couldn’t get Kayaba). Now I understand that Ohlins has a 2wt oil, especially formulated for ICS.

My problem appeared because of a to tick oil, or because I didn’t done the drilling and the chamfer on the rod?

Please help, I rode a 525EXC today and it’s cornering better than my YZF !!!!

 

[anca]

Hi Zenith, does you fork became harsh after modifying it? I see you are online :)

 

[Zenith]

No I didn't notice them being harsh, I just thought all round the modifications hugely improved the handling of the front end. I'm using almost all the fork travel, though I'm about 200lbs with gear.

My supposedly un-leakable Synergy seals are now leaking by the way. 3 months doesn't seem that good to me from a set of seals, at least not at that price! I could buy 4 sets of ordinary ones for the money, that would have got me through at least 2 seasons...

 

[James]

If you take the forks apart and clean the seals as opposed to replacing them each time they leak, they may last two seasons or more. It's usually dirt in the seal, not a tear. They definitely don't wear out in three months. I haven't replaced a seal of my own in 4 years.

I feel like my YZF forks got harsher after the mods but that may be for two reasons:

1. Before the mods, I was most likely running low on fluid in short order.

2. I rearranged the mid-valve to get rid of the bleed on teh compression. This may have also affected the rebound as the fluid now has to pass 100% through that circuit.

#1 may be the difference you are feeling. What do you weigh?

 

[anca]

I’m 180 lbs without gear.
Today I extracted from each fork 30ml oil and it helped some with harshness, but the fork is still blocking at 20mm from bottom. So it’s not from oil level, I guess it must be from ICS, I’ll experiment further.
I don’t know if I have to drill the piston and chamfer the rod ( the ICS is well bleed by mop method), I’m afraid to do it because it is a permanent modify.

 

[James]

I can't imagine what would be restricting the travel unless you put it back together wrong. Did you get all of the spring washers/bushings back in the right place? There is an upper and lower one that go on the outside of the damper assembly with the fork spring. Also, where did you put the 9mm spacer?

 

[russ17]

Guy's, I would look at the TCV ( Transfer control valve) This is position sensitive. Great for anti bottoming.

Russ

 

[anca]

As far as I remember everything is put together correctly as is sown in the expanded view in the book. The ICS spacer is 8mm and is installed on top.
Anyway I will disassemble the fork, I’m very unsatisfied with the new turning habits of my bike, I feel like the fork is not diving enough in turns.
If you have any idea of what could be wrong please let me know, I don’t want to do the same mistake second time.

 

[dishman]

fork oil for kyb blader

i have a 2005 250f. i need to know the proper amount of oil