Help, DIY pro style fork revalve yz450f -10

[kavorka-racing]

Same as my earlier post about shock revalve but for the fork.

Allthough I am not pro fast I have found that in general what works for the pros works for me. Help me set up my new 2010 yz450f suspension. I have complained through my youth about poor suspension. This time around I am determined to get good boingers. After some time off I returned to riding last fall on a 2009 yz450f. I am 6'1" 180 lbs. My best setting on the 2009 was:

15 cc oil added to fork

comp zero out (all closed)

stock rebound fork and shock

shock hsc 3/4 out (stock 1.5 out)

shock lsc 2 out

stock spings, race sag 100 mm (not played with sag yet)

Basically the stiffer I got the compression the better it suited me. Not just on hard inpacts but it became more predictable and even felt more plush. Maybe it did not hit me less but it hooked up, was predictable an gave me confidence. It may hit me but it must always keep the wheel planted. So for my 2010 I have done a plan for my fork shimstack. For now I am just shuffling shims. If needed I will off course buy any parts necessary for success.

fork base

……………………. stk ……………………. mod

……………………. 15 - 32.12 ………………. 15 - 32.12

……………………. ........ ……………………. 30.3

……………………. 30.12 ……………………. 30.12

……………………. 28.12 ……………………. 28.12

……………………. 26.12 ……………………. 26.12

……………………. 24.12 ……………………. 24.12

……………………. 22.12 ……………………. 22.12

……………………. 20.12 ……………………. 20.12

……………………. 18.12 ……………………. 18.12

……………………. 17.3 b …………………. 17.3 b

fork mid

……………………. stk ……………………. mod

……………………. 20.12 - 4 ………………. 20.12 - 5

……………………. 17.12 ……………………. 17.12

……………………. 14.15 ……………………. 14.15

……………………. 2 - 11.25 b …………………. 2 - 11.25 b

fork reb

……………………. stk ……………………. mod

……………………. 20.12 - 3 ………………. 20.12 - 2

……………………. 12.12 ……………………. 12.12

……………………. 18.12 ……………………. 16.12

……………………. 16.12 ……………………. 18.12

……………………. 14.12 ……………………. 14.12

……………………. 12.12 ……………………. 12.12

……………………. 11.12 ……………………. 11.12

……………………. 2 - 10.25 b …………………. 2 - 10.25 b

For the base I added one 30.3. It may not look like much but one 0.3 mm shim is many times stiffer than a .12 mm shim. Maybe I should just go with a bigger clamp instead, like 22 mm?

Added one faceshim to the midvalve. Gives less float and stiffer damping over the entire speed range.

Rebound is a little softer too.

I believe I am happy with the stock springs. The 2009 suspension was to soft for me but the 2010 has stiffer shock spring, and sinse I plan to go with stiff damping I think the stock 2010 springs will be good.

I am willing to work for it and pay for it. I am convinced I will have to do both. This is where I start the journey . I have a thread going for the shock too.

your input is valuable.

[Jusa]

I would say that your fork will be very stiff because that one 0.3 shim. It is almost 25 times stiffer than 0.11 shim = 25 more 30shims:thinking: and you are going to stiffen mv also ,0.11 less float is a big diifference compared to stock and stack is also stiffer.?

But if you like arm pump it's ok:smirk:

[kavorka-racing]

Thanks for your input. And yes, as evident from my writing about that shim I feel uncertain it is a good idea. That's why I asked if I should go with just increasing the clamp instead. From your reply I conclude that I must not use that shim. Also such a thick shim could be proned to fatigue.

No, armpump is nothing I favour. I have problem with my arms pumping up so I must learn to ride more relaxed. In order to dare loosen my grip a suspension that I can trust and that induces confidence is of utmost importance.

Apart from the debacle with the (0.3/0.12)^3 times stiffer shim, what should I do? How will my mid valve mod work?

[Jusa]

Here are some info about the shim thicknesses

http://www.mx-tech.com/downloads/Shim_Conversion.pdf

Going from 17mm clamp to 22 clamp will make the stack super stiff. By changing the clamp to18mm make a big difference.

Your mid valve mod will make the fork much stiffer. You can make that mod without any bv mods and you will still have much stiffer fork. Personally I would make smaller changes.

[kavorka-racing]

Ok, go with the bigger clamp but in reasonable increments. I do expect the mv mod to make a very discerable difference. But judging by my clicker setting it would be justifiable, right? I am worried that a stiffer mv would cavitate if not combined with a stiffer bv to keep the cartridge above cavitation pressure. And that a bv mod alone would give to little hs comp. But I really have no clue to how big a change I need to do to get the right amount of change in my suspension. I know the rules of physics but not the fine print of suspension. That's why I appreciate your experience so much.

[mog]

the mid change is a pretty big one, on forks the mid has a huge effect, changing a 14mm to a 15mm is something you will feel. Closing the float is also a big change,

so your mid will make a big difference with a extra shim and less float, if it was me i would do that and one step up on the clamp, the rebound could cope with less shims so that looks ok.

[Jusa]

When stiffen mv and try to copensate it with stiffer bv, you will have too much overall damping and that will make the fork very harsh.

I guess you need 4.7N or 4.8N springs instead of much stiffer valving if you are't a pro rider. Minor changes to mid to control diving and a bit stiffer base will give good results. Yzf 450 -10 reb pistons haven't bleed holes, have they?

[kavorka-racing]

So both of you (mog and jusa) believe that the mid and rebound mods I listed is good and that I should go to 18 clamp on bv. I like it. Have anyone experienced cavitation problems after mv mods? Is it common to mod the mid valve about as much as I suggest?

You make me feel good about this, thanks.

[mog]

some people run the mid with no float and a similar base so dont worry about cavitation.The mods you describe turn the fork from a nice mx fork into a decent fast rider setting.

[Jusa]

I wouldn't soften reb, but this my opinion.?

[kavorka-racing]

Glad I do not have to worry about cavitation. Decent fast rider setting sounds like a good baseline. Maybe I should consider changing the 14 to a 12 on mv to make it a little less hs.

Jusa, I did soften the reb. Do you suggest I soften it more?

May I have your opinion on my planed shock mods please?

[mog]

jusa is right ? i was thinking of the 07 fork with 4 face shims on rebound, yours has 3 already, so i would stick with std rebound.

here is the 07 one which was a tad heavy

10.25

12.12

14.12

16.12

18.12

13.12

20.12

20.12

20.12

20.12

[Jusa]

I wouldn't soften it at all.

[Jusa]

...and I assume that softer low speed reb is because no bleed hole at all on the piston

[kavorka-racing]

My bad, I read "would" instead of "would'nt" sorry. I will think about your advice and maybe leave the rebound.

I don't know for sure but I have heard "no bleed in new KYB forks" before so I assume you are right.

[mog]

interesting fact, i missed that info when they came out.

[racerfmx450]

?

for pro riders ~ 80 KG.

Base

32.11 18

30

28

26

24

22

20

18.30

bleed

11.25 3x

16.11

18.11

22.11 2x

mid

20.11 4x

14.10

18.11

16.11

14.11

11.3 2x

17.3 2x

0.15 float,

.48 springs

360 ccm oil.

C10

R8

another opinions??

stock reb unless you riding in deep sand!!!

[kavorka-racing]

Thank you racerfmx, that is good info. I may use that straight up. It is in many ways similar to what the earlier discussion agreed upon. bv = 18 clamp +3 face shims, mv = slightly closed float. I am getting confident I could end up with a pretty good setup on my first try.

racerfmx, is that your setup or who is riding that?

[racerfmx450]

one of my Friends Ride with this Setting.

(YZF 450 2010)

80 KG Fast National Rider.

Nobody can say exactly what works for you at best, but you can try this and then you see how it works.

its noticeable stiffer and more stable than stock.

try it, rate it and tune it if necessary

?

[kavorka-racing]

Thanks, I'll try something very similar to what you suggest. Can someone tell me what the stock float is on the 2010-11 yz450f kyb forks?