exc 300 2009 fork shim stack

[dryz250]

I have a 2009 exc300 used for tight rocky enduros and hare scrambles. I weigh 190lbs dressed and have lowerer the rear shock by placing a 5mm spacer to get a better feel on whoops and turns. I have presently the standard springs 4.2/6.9 but have 4.4/7.2 as well ready to go on.

I also revalved the forks according to Jaymans suggestions for this bike.

These are as follows

BV

24 .10 X 4

15

24

22

20

18

16

14

9.5 .30

16 .25

MID

20 .10 X 3

18

16

14

10 .20

float 0.55

REB

20 .10 X 2 delta

12

20 delta

16

14

12

10 .30

14 .25

130mm air gap

Fork is much more compliant and goes through rock beds much better than standard without deflecting and has no mid stroke spike as before . On faster open tracks I get some deflection when hitting 10 cm rocks and head shake.

I have fork preload 1 1/2 turn in to get 40/70 sag and the clickers set at 18/18 rb/comp.

Shock has 18 LS 1 1/2 HS and 22 reb with 35/110 sags

Should I swap front and rear springs and increase the rebound on the forks to stop the high speed deflection?

Any way to make this bike better would be appreciated.

Thanks

[frezno]

lowerer the rear shock by placing a 5mm spacer

[...]

On faster open tracks I get some deflection when hitting 10 cm rocks and head shake.

?

BV

24 .10 X 5

16

24 .10 X 6

22

20

18

16

14

12

9.5 .30

16 .25

MID

16

20 .10 X 3

18

16

10 .20

float 0.55

[EDS]

As Frezno knows I am not a fan of the mid valve bleed.

Before you revalve to The Frez no spec, try

Slightly more sag ie

Static 36-40mm

Rider 112-118mm

and less

High Speed Compression ie

1.75 - 2

Also try Compression on the fork at 20 out.

This might help.

[dryz250]

As Frezno knows I am not a fan of the mid valve bleed.

Before you revalve to The Frez no spec, try

Slightly more sag ie

Static 36-40mm

Rider 112-118mm

and less

High Speed Compression ie

1.75 - 2

Also try Compression on the fork at 20 out.

This might help.

Thanks,

I will try just playing with the clickers first and get more sag on the back.

Won't the lower compression make things worse as speed goes up?

What about heavier springs, was thinking of adding a 44 to the front to get anaverage of 43 and a 7.2 on the shock to get the right sag setup?

Also I was told that the 130 air gap is too low, should go up 125 to 120?

[frezno]

As Frezno knows I am not a fan of the mid valve bleed..

i'm not either. just in many situations the WP forks just shouts for it (and that's true for just the WP's)

Can't tell why, probably because of the piston characteristics, but it does work very, very good (in appropriate cases).

Additionally he has a 5mm lowering of the shock which is imho rather suboptimal. He has to get rid of this.

[russ17]

As Frezno knows I am not a fan of the mid valve bleed.

I find most do not like the bleed shim on the mid has more to do with getting the rebound correct . Any thoughts on this?

[dryz250]

i'm not either. just in many situations the WP forks just shouts for it (and that's true for just the WP's)

Can't tell why, probably because of the piston characteristics, but it does work very, very good (in appropriate cases).

Additionally he has a 5mm lowering of the shock which is imho rather suboptimal. He has to get rid of this.

Why do you think it is suboptimal? On the contrary it feels it has better turning and handling than before.

[wblake]

if i was you i would feel that i change too many things at once and play with one at a time!!!

[dryz250]

Wblake Hi!

It might seem that I am changing too many things at a time....

When I lowered the rear I follow what many have done on this forum and ktmtalk, by altering the geometry of the chassis to give it more trail and to get the front to bite when leaned over in a turn and more stable on the fast open tracks.

Now the fork revalve is another story. The stock 2009 forks are better than previous years but need to be addressed for their inability to follow fast rocky trails, having a tendency to jump out of line if pushed too much. Also they tend to go through the mid too fast. For hobby trail riders they are ok, but not for anything more serious.

I got the shim stacks from Jayman who has done extensive testing on these bikes and they do seem to work much much better than stock.

You see, I am trying to set up this bike so I can confidently ride through all the rough extreme trails we go to plus having fun on the practice tracks.

[wblake]

just from what i read, not knowing how much you test each setting you go through am not very clear where your improvement comes from...

eg i dont know if your turning handling improvement come from less sag, or shock mod or revalve or respring since in you previous tread you played around a bit with 6.9 and 7.2....

[dryz250]

The handling improved by the lower rear end, pushing the fork angle out is like going to a 22 offset triple, just like you have on your husa.

The spring has nothing to do with the handling but with the way the shock damping works, as well as the fork revalve.

Lots of guys use the x-bushing not only for lowering the rear but as an overall performance improvement. I didn't go through that route since I didn't want to grind metal, and the spacer is easily removed for the next owner. Also take a look at all the MX pros, they all lower their rear end for better braking and cornering.

try lowerring your sag to 118 on your bike and see how it goes.......

[wblake]

getting the back end low to kick the offset to 22 i can see where you coming from but you can achieve that with running more static/rider sag and compesnate with the triples and fork sag!!!

the spring thou play a major part on geometry, you need to adjust sag first and then worry about the damping....im you change springs now you many need revalve again... i am not an expert but surly it has an effect on low rebound i guess the same for high speed rebound...

i had a post the other day on springs and damping and all the answers igot was just that!!

[dryz250]

The rear spring change will be compensated by lowering HS and increasing RB. I am still at the middle of the adjustment range. Also the spring change from 42 to 43 has a minimal effect on the valving of the forks.

Anyway I like to play with my bikes till I set them up to where I like them. Its all a personal thing if you know what I mean.

[PMK]

Shortening a rear damper is not for everyone. When done though, and to a not overdone amount, it will calm the bike down in many ways.

Yes the trail dimension is changed. This helps sidebite on the tire. That can be important. Also, it will make the transition from the motorcycle being upright entering a flat turn, next transitioning the turn and finally exiting the flat turn more predictable with tendency to go from an understeer on entry, to a controlled apex that can violently snap into oversteer.

Bottomline in flat turns, the bike is often better.

With a bermed turn, the effects are less noticed in turning but often the entry and exit will carry more speed, resulting in a faster overall turn.

When braking the rear end does not rise as much. The key here is that trail is maintained with better weight bias onto the front tire, which supplements corner speed. Also, if the ground is hacked up, the bike is easier to ride with it not tapping your pants as it hops around.

When descending, you are allowed better use of the brakes since the rear will not rise, shifting the bike CG up and forward. When the non shortened damper bike is on the incline and brakes are applied, more weight will go forward above the axle center giving a pitching type effect. Also, this shift in weight bias makes the rear brake less effective.

The debate of shortening or not so often depends on the riders ability and speed, the terrain, and of course the geometry of the actual motorcycle. Not every brand or model needs this. Many KTM's often have a better feel when ridden after properly shortened.

Those that believe the same results are obtained via a sag adjustment might notice some improvement. Often though it is a false sense of security and comes up far short of truly dialing in the damper length and chassis geometry.

A sag adjusted bike will not be as planted as the shortened bike, the suspension has the ability to move a bit more than some folk like. The sag adjusted bike will not brake as well on account of the additional CG shift and rear end raising up. Also, as the non shortened bike puts more weight forward, the rear will hop around more and hop higher. Descending the non shortened bike will pitch the rider forward.

These are all primarily just rolling tendencies, once the effects of driveline induced squat and anti-squat are added in, the concept of limiting just how far the rear end can move downward becomes more important.

Again, not every rider needs this, but if your motorcycle has the possibility to get better by this simple change it is worth testing.

As for the OP and his forks, bleed shim or no bleed shim, I am of the opinion get the tubes to slide first, then start testing your shim settings. Often KTM deflection is either mechanically bound forks, low quality production tolerances on the finishes. Usually once the shim setting seem better without good sliding components, the settings work in a very narrow window.

Best of luck with it.

PK

[dryz250]

PMK

Now that is a great write up explaining the effects of shortening the rear shock. That is exactly what I am feeling riding through exactly the same loop which I have thousands of times when compared to my previous bikes, especially on flat hardpack turns and downhill braking whoops.

Concerning the forks, well the 2009 OC's are much better than all the previous years, mind you I have changed to the raved SKF seals and forks have absolutely no stiction! Just touch the bike and you can feel the forks moving!

[robben10]

Dryz250 stop waste your time/money doing a wp way revalve. My opinion is to do a MX-TECH enduro revalve , it will work amazing for our terain.

[dryz250]

Dryz250 stop waste your time/money doing a wp way revalve. My opinion is to do a MX-TECH enduro revalve , it will work amazing for our terain.

Robben10

Can you give me an address and telephone# to get this done?

Are you talking about forks or both?

[wblake]

Shortening a rear damper is not for everyone. When done though, and to a not overdone amount, it will calm the bike down in many ways.

Yes the trail dimension is changed. This helps sidebite on the tire. That can be important. Also, it will make the transition from the motorcycle being upright entering a flat turn, next transitioning the turn and finally exiting the flat turn more predictable with tendency to go from an understeer on entry, to a controlled apex that can violently snap into oversteer.

Bottomline in flat turns, the bike is often better.

With a bermed turn, the effects are less noticed in turning but often the entry and exit will carry more speed, resulting in a faster overall turn.

When braking the rear end does not rise as much. The key here is that trail is maintained with better weight bias onto the front tire, which supplements corner speed. Also, if the ground is hacked up, the bike is easier to ride with it not tapping your pants as it hops around.

When descending, you are allowed better use of the brakes since the rear will not rise, shifting the bike CG up and forward. When the non shortened damper bike is on the incline and brakes are applied, more weight will go forward above the axle center giving a pitching type effect. Also, this shift in weight bias makes the rear brake less effective.

The debate of shortening or not so often depends on the riders ability and speed, the terrain, and of course the geometry of the actual motorcycle. Not every brand or model needs this. Many KTM's often have a better feel when ridden after properly shortened.

Those that believe the same results are obtained via a sag adjustment might notice some improvement. Often though it is a false sense of security and comes up far short of truly dialing in the damper length and chassis geometry.

A sag adjusted bike will not be as planted as the shortened bike, the suspension has the ability to move a bit more than some folk like. The sag adjusted bike will not brake as well on account of the additional CG shift and rear end raising up. Also, as the non shortened bike puts more weight forward, the rear will hop around more and hop higher. Descending the non shortened bike will pitch the rider forward.

These are all primarily just rolling tendencies, once the effects of driveline induced squat and anti-squat are added in, the concept of limiting just how far the rear end can move downward becomes more important.

Again, not every rider needs this, but if your motorcycle has the possibility to get better by this simple change it is worth testing.

As for the OP and his forks, bleed shim or no bleed shim, I am of the opinion get the tubes to slide first, then start testing your shim settings. Often KTM deflection is either mechanically bound forks, low quality production tolerances on the finishes. Usually once the shim setting seem better without good sliding components, the settings work in a very narrow window.

Best of luck with it.

PK

PK thank you for this more in depth inside of the suspension functions!!!!

2 questions come up what will be the effects having a shortened shock on a bike thats not required of it??

will the CC forks have a better built quality than the OC or you are refering to a more elaborate work like higher quality seals, DLC cotings or what else to make the forks slide as you say

[wblake]

DRyz250 obviously you have done extensive testing on this keep us posted

[dryz250]

wblake, the CC forks keep the front end higher in the stroke, so one problem is solved, but for braking downhill highspeed whoops the shorter shock will help. Also get the rear wheel way back helps too. Everything adds up.