excf-250 2009 new setting

I am planing for some changes for a fast enduro racer , on the oem fork of excf-250 2009.New fork works ok but for serious racers is soft and fast on rebound.The stock setting is

COMP std changes

24x0.10 (6) *add 1*

23x0.10

22x0.10

20x0.10

18x0.10

16x0.10

14x0.10

12x0.10

9.5x0.30 *10x0.30*

16x0.25

MID std

18x0.10(2) bleed * remove 1*

20x0.10(3) * add 1*

18x0.10

16x0.10

11x0.20

REb

20x0.10 (3 triang)

12x0.10

16x0.15

14x0.15

12x0.15 *add one 13x0.15*

10x0.30

14x0.25

Spring 4.2 * spring 4.4 rider weight 81 without gear*

oil level 110mm

Any recomentation for this?? Thank you, robben:worthy:

looks good but the rebound , you wont feel that change IMO.You need to do something above or below the crossover, or use a bigger clamp.

It would not make a bad mx fork setting -better than std on a 250sxf....

looks good but the rebound , you wont feel that change IMO.You need to do something above or below the crossover, or use a bigger clamp.

It would not make a bad mx fork setting -better than std on a 250sxf....

Maybe a 16x0.25 clamp on rebound mog? This fork has a loose feeling on rebound..

clamp on the 12, thats a approx 20% more damping, thats hould be close.

I would do this:

COMP std changes

24x0.10 (6)

23x0.10

22x0.10

21x0.10<add>

20x0.10

19x0.10<add>

18x0.10

17x0.10<add>

16x0.10

14x0.10

12x0.10

9.5x0.30

16x0.25

MID std

18x0.10(2) bleed <remove 1>

20x0.10(3) <add 1>

18x0.10

16x0.10

11x0.20

REB

20x0.10 (3 triang)

12x0.10<replace with 16x.10>

18x0.15<add>

16x0.15

14x0.15

12x0.15

10x0.30

14x0.25

What about the midvalve? Wont those shims deform if a proper midvalve isnt put in?

What about the midvalve? Wont those shims deform if a proper midvalve isnt put in?

The 09 fork has 20mm MV shims, same as all other "modern" forks. So the shims should hold up just fine.

There's a reason they don't use 18's in the rebound stack with 20mm deltas. Put an 18 against a 20delta and you'll see what I'm talking about.

I myself would prob switch to .46's on the four stroke and lower the oil. And also get the mid dialed in first before you change a bunch of stuff on the BV.

There's a reason they don't use 18's in the rebound stack with 20mm deltas. Put an 18 against a 20delta and you'll see what I'm talking about.

I myself would prob switch to .46's on the four stroke and lower the oil. And also get the mid dialed in first before you change a bunch of stuff on the BV.

But this is a 250 four stroke bike. Springs 4.6 probably too stiff for this....I think 4.4 or 4.3 would be fine for technical enduro tracks.

I have also try on those forks lower oil heights but the fork become harsh...so i go back to 110mm oil height.

LEW also suggest to put a 18 shim not against delta but on the backplate ....

But this is a 250 four stroke bike. Springs 4.6 probably too stiff for this....I think 4.4 or 4.3 would be fine for technical enduro tracks.

I have also try on those forks lower oil heights but the fork become harsh...so i go back to 110mm oil height.

LEW also suggest to put a 18 shim not against delta but on the backplate ....

Most people here in the US seem to go crazy with spring rate. Big kick over here about not using any preload...I disagree to-a-point. On fork springs I have NO problem with using 10mm of preload. Lots of guys here want the springs rattling around loose...

The 09 Husaberg FE450 has this compression stack and it's too soft for the fast guys:

BV

(7)24x.10

23x.10

22x.10

21x.10

20x.10

19x.10

18x.10

17x.10

16x.10

14x.10

12x.10

9.5x.30

Removing one bleedshim from the mid, won't do enough getting yr rebound dialed in?

Most people here in the US seem to go crazy with spring rate. Big kick over here about not using any preload...I disagree to-a-point. On fork springs I have NO problem with using 10mm of preload. Lots of guys here want the springs rattling around loose...

The 09 Husaberg FE450 has this compression stack and it's too soft for the fast guys:

BV

(7)24x.10

23x.10

22x.10

21x.10

20x.10

19x.10

18x.10

17x.10

16x.10

14x.10

12x.10

9.5x.30

I agree .Us riders prefer bikes low in the rear (soft springs and low sag) and harder on front fork.This gives stability and needs agresive riding.In europe we adjust bikes more balance for more technical tracks for mx and special stages for enduro.For this preferances KTM factory for 2009 produce diff. settings and springs rates for us and others for europe bikes.

Removing one bleedshim from the mid, won't do enough getting yr rebound dialed in?

It would make some difference but maybe not enough...Any thoughts??

It would make some difference but maybe not enough...Any thoughts??

What was the reason for your proposal in the first post? Was it just some random shim shuffling or did you have a plan?

Reason I'm asking is, you already have a huge bleed on the rebound because of the bleed shim(s), you have a 2-stage stack with a rather small crossover for even more low (mid?) speed rebound bleed, yet you want to add a shim on the very opposite side of the stack deep in the high speed part?

Also, have you asked yourself what KTM had in mind with this rebound configuration and why? For a fast enduro racer I'd look at the 09 XC stacks - they have been posted in the suspension forum on KTM-Talk and I'm sure Lew has them also. Even though this is for the TC forks, this years OC and TC forks share the same internal dimensions. IMO it would be worth a try, but that's just my unqualified 2 cents ...

Michael

But this is a 250 four stroke bike. Springs 4.6 probably too stiff for this....I think 4.4 or 4.3 would be fine for technical enduro tracks.

I have also try on those forks lower oil heights but the fork become harsh...so i go back to 110mm oil height.

LEW also suggest to put a 18 shim not against delta but on the backplate ....

Uh no he didn't suggest putting against a backing plate. He inserted it into the rebound stack after the crossover.

And you're right on the springs I'm sorry. I was thinking 80kg was more but it's only around 175lbs right?? So .44's would prob be perfect.

And Lew I totally agree with fork spring preload. I've never liked the feel of front forks with no preload on the springs. I always try and shoot for 6-9mm if at all possible. I think the fork is too busy in the first couple inches of the stroke with no preload.

Are you bottoming the forks at 110mm??

Uh no he didn't suggest putting against a backing plate. He inserted it into the rebound stack after the crossover.

And you're right on the springs I'm sorry. I was thinking 80kg was more but it's only around 175lbs right?? So .44's would prob be perfect.

And Lew I totally agree with fork spring preload. I've never liked the feel of front forks with no preload on the springs. I always try and shoot for 6-9mm if at all possible. I think the fork is too busy in the first couple inches of the stroke with no preload.

Are you bottoming the forks at 110mm??

Slight bottoming.When i try 100mm fork become harsh.

What was the reason for your proposal in the first post? Was it just some random shim shuffling or did you have a plan?

Reason I'm asking is, you already have a huge bleed on the rebound because of the bleed shim(s), you have a 2-stage stack with a rather small crossover for even more low (mid?) speed rebound bleed, yet you want to add a shim on the very opposite side of the stack deep in the high speed part?

Also, have you asked yourself what KTM had in mind with this rebound configuration and why? For a fast enduro racer I'd look at the 09 XC stacks - they have been posted in the suspension forum on KTM-Talk and I'm sure Lew has them also. Even though this is for the TC forks, this years OC and TC forks share the same internal dimensions. IMO it would be worth a try, but that's just my unqualified 2 cents ...

Michael

Michael,

I have done many tests with 2009 fork and shock.I have try also CC and OC forks. Exc , XC and MX settings.Also SXS settings.I have try progressive springs on the PDS with help of a great guy from Australia.

My target is to make the ktms suspension work for rider preferances , but also to suit to Greek dry,slipery with many stones terain. So as you propably know Ktm suspension needs a little help for those terain.

My target is to make the ktms suspension work for rider preferances , but also to suit to Greek dry,slipery with many stones terain. So as you propably know Ktm suspension needs a little help for those terain.

I dare to say that I know the Greek terrain you describe very well from many trips to the Peloponnes. Having said that, the MX-Tech suspension that I'm using works very well under these conditions as it provides a much broader range that the stock KTM/WP. It gives good stability on the fast gravel roads, yet can soak up the rocks which are always present. Made a MXT setup for a friend who lives and rides around Athens and he is pretty happy with it too. I'm not saying that your tries in revalving the stock stuff are useless, I'm only saying that the MX-Tech stuff works well for me in your conditions.

Also, the stock KTM rebound is not that strange or bad, BUT if you drastically change the setup (like reducing the free bleed) you need to adjust it accordingly. The 09 XC uses a bleed shim on the MV, yet the rebound is pretty standard. That's because it is a small diameter bleed shim and the big face shims will mostly cover the ports on the rebound stroke. The 09 EXC on the other hand uses large dia bleed shims which will also provide significant bleed on the rebound stroke - therefor the stiff rebound stack with all the 0.15s. IMO the 2-stage rebound stack is a mistake here, but they get away with it on the EXC . Nevertheless I'm sure that much free/low speed bleed is responsible for the "loose feel" on the front your rider seems to be complaining about.

Michael

What float are you running on the mid? I would try and get more damping from the mid sooner. Use your revised stack with the 10x.3 clamp on the BV. Remove the bleed shims from the mid. Try a low float, tapered stack on the mid. And run a moderate rebound stack something like this

(3)20dx.1

14x.1

20dx.1

16x.1

14x.1

13x.1

12x.1

10x.3

backer

These 09 OC forks are pretty awesome I think.

How FAST is the guy you're tuning for?

What float are you running on the mid? I would try and get more damping from the mid sooner. Use your revised stack with the 10x.3 clamp on the BV. Remove the bleed shims from the mid. Try a low float, tapered stack on the mid. And run a moderate rebound stack something like this

(3)20dx.1

14x.1

20dx.1

16x.1

14x.1

13x.1

12x.1

10x.3

backer

These 09 OC forks are pretty awesome I think.

How FAST is the guy you're tuning for?

Float is 0.7. The rider is very fast.Greek enduro champion . he finished 12 last year at european championship.Some times rides MX and get on podium!!Realy agresive rider...

I use on his bike sxs suspension with xc setting with some minor changes.Now i am trying to make OC fork work good for him.The main problem is the loose feel of the fork that makes the bike good on straight but always nervous when cornering .

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!


Register a new account

Sign in

Already have an account? Sign in here.


Sign In Now