Kayaba TC at my KTM

[mattias]

Hi all guys and suspension-gurus. I ride a KTM 300EXC 2011 with a Kayaba TC fork from 2006 and it works great, except on one thing. It’s feel so stiff at high-speed damping at small stuff and it just throw away the front-wheel when I hit obstacles up to 100mm. The fork does not bottoming out, i have about 50-60mm left of the travel. I don’t really know what to change but I have some ideas. The current setting I have now is as follow.

Base                                  Mid                                     Rebound

32-0.11  12                        20-0.11  3                          20-0.11  5

30-0.11                              18-0.11                              13-0.11

28-0.11                              16-0.11                              18-0.11

26-0.11                              14 0.11                              16-0.11

24-0.11                              11-0.3    2                          14-0.11

22-0.11                              17-0.3    2                          12-0.11

20-0.11                                                                          10-0.25

18-0.11                              Float:0.4mm

16-0.11

14-0.3

 

My thoughts about the base are: change 14-0.3 to 14-0.1 and  maybe remove 16-0.11 and change the thickness from 0.11 to 0.1 at 18 ,16 ,14 in the midvalve.

 

I run Maxima 5w both in inner and outer chamber. Oil height about 330ml.

What changes do you all expert on suspension suggest  I should do.

 

Edited August 26, 2013 by mattias

[Vietze]

Changing the 14.3 to a 14.1 wont do nothing. Keep the 14.3 where it is.

If you remove the 16.11 and keep the 14.3 clamp the 18.11 will most likely hit the base plate. You dont want that either.

 

Changing kyb .11 shims to .1 shims can make a noticeable difference if you change a lot of them. It wont make much of a difference if you just change a couple of them.

 

My recommendations, assuming that you're using the right springs:

Your ICS springs are most like 20 N. Get softer ones. 17 N or 14 N work. You may want some preload on them if you use 14 N.

 

Does your fork have a bleedstack? Shimstack with 22mm faceshims under the usual basevalve?

 

Basevalve:

add a 24.1 crossover after 5 faceshims

 

MIdvalve:
leave it alone

 

Rebound:

remove 2 faceshims
 

Stick to your oil and oillevel.

 

Try it and report back.

 

 

If you still have problems afterwards you may need an altered mv, but I see more problems with the current base, ICS and reb.

 

cheers

Edited August 26, 2013 by Vietze

[delleetodd]

_{Can you give us some more details on how you fit the KYBs to your KTM?} 

[mattias]

_{Can you give us some more details on how you fit the KYBs to your KTM?} 

If you look here you see how I done. It's post #805   https://www.thumpertalk.com/topic/947479-what-have-you-done-to-your-ktm-today/?p=10813296

I done some revalving tonight and I will test it tomorrow. I didn't do exactly as you'r idea Vietze but I will be back with report.

[Phil_S]

OP, What is your thinking.behind.those changes?

If you are riding.off-road, I would reduce bv clamp size, install xover in base, and give the mid more float.

[mattias]

have done some testing today and it didn't work as I wish. What I did did was to reduce the clamp to Ø11 and removed Ø16x0.11 from the base, also added a xover Ø24x0.11 at position 8 in the base. It works much better over the small and medium size of stone but it was much, much to soft.  I'm riding swedish enduro with roots and stone.  Think I will increase the clamp to Ø12, the float how will that effect if I increase that up to 0.5mm.

[Vietze]

Using more float will soften the fork even more...

 

Do what I suggested, keep the 14mm clamp on the base.

Keep the 24.1 crossover. This one made the fork better over the small and medium size stuff.

 

If you still have problems with small bumps change the ICS, as already been said.

[Phil_S]

I had a 09 YZ450 with I assume similar fork.  I ran the below stack.  Mid A pace, offroad/enduros only, 230lbs.  I would not call it great, I would call it good and much better than stock.  The stock stack on the front end (0.35float with no xover in Base and larger base clamp) was horrible on high speed impacts like rocks at speed.  The bars would about yank out of your hand when you hit rocks at speed.  I found that increasing float helped with super HS impacts like what I thought you were describing, but something may be loss here in the translation.  Vietze is a very smart guy.  If his suggestions don't work, try more float and stiffing up the BV stack to bring in the bottoming control you need.

 

 

BV 32x.11 (2) 28X.11 32x.11(12) 30x.11 28x.11 26x.11 24x.11 22x.11 20x.11 18x.11 11x.1.43     MV 20x.11(3) 17X.11(3) 11x.25(2) 17x.3(2) Float 0.5