Sanity Check Please - 2005 YZ250F Woods Stack

Just wanted to throw this design out for a quick look before I assemble it in case anyone sees any glaring errors. I have done a few re-valves with some great success but always get wrapped around the axle for a few days studying forum threads and end up on all sorts of tangents. Then I usually go back to the basics and stop "Nuking" it. The design below is about as basic as it gets I suppose and essentially a shim removal/shuffle project. This is for a 2005 YZ250F. The racer is a 215 pound, top 5, 250 C Class Hare Scrambler. The goal is to get him off the motocross set up and into something a little more compliant for east coast hare scrambles. Here is the plan:

7mm spacer to top of stock ICS Spring to relocate the piston in a lower position per Terry Hay's suggestion in previous TT threads. Softening the compression, softening the rebound and adding some MV float.

Please feel free to smack me around if this is a bad design.

Stock

Comp

24 x 12 (11) Remove 7

20 x 12

18 x 12

16 x 12

14 x 12

11 x 25

13 x 50

Rebound

21 x 12 (6) Remove 3

16 x 12

20 x 12

18 x 12

16 x 12

14 x 12

12 x 12

11 x 25

19 x 1.62

Mid

16 x 12

22 x 08 (3) Remove 2

18 x 08

16 x 08 Remove

14 x 08

12 x 30

16 x 12

22 x 42

(I think the float will come out to .7mm)

ihmo that won't work, esp. that kind of soft base while having a bleeder at the mid.

doesn't that guy has stiffer springs for his weight?

No reason to go softer with the rebound, you rather should go stiffer

I worry the mid is also too soft

ihmo that won't work, esp. that kind of soft base while having a bleeder at the mid.

doesn't that guy has stiffer springs for his weight?

No reason to go softer with the rebound, you rather should go stiffer

:smirk:

Lots of bleed in 05 mids. The piston band has a 1mm gap, bleed hole in the piston and a bleed shim

as Marcus stated a bit soft on the mid comp.

:smirk:

Lots of bleed in 05 mids. The piston band has a 1mm gap, bleed hole in the piston and a bleed shim

as Marcus stated a bit soft on the mid comp.

Thanks everyone for the tips. Russ17 - If I am reading your reply correctly, you are giving a thumbsup on Frezno's comments and adding that there is already enough bleed on the 05 system right?

If that is correct then are you saying that there is no need to create more float on the mid? How much float would you recommend? Stock? BTW, the racer will be sprung correctly when I'm done also.

Also, don't know what you mean by soft on the "mid comp". Do you mean I softened the mid and compression too much?

Looking over the data from previous jobs and hearing your comments, I think I'll leave the rebound alone (Stock).

You know...This sounds like it's turning into the revalve I did on my own 05 YZF. If I remember correctly, I removed half of the HS compression shims, didn't touch anything else and used Dave J's fluid and it was the best forks I have ever ridden on. I could fly across just about anything and the front tire stayed connected. It was awesome. Any comments on the 7mm spacer on top of the ICS?

Again, thanks for the tips guys. Rick Hall (757) 214-5334

yes doing the mid and the base is going too far, use the mid and rebound std and do the base as you did on the older bike, and put the spacers on the ics(and main springs if std)

Thanks MOG for the clarification. I should have stayed with that plan anyway since it worked so well on my old 05 YZF. The one thing I didn't do back then (2 yrs ago) was the ICS spacer. Maybe it worked well anyway because I used Dave's anti-cavitation fluid. That stuff is great. I have done ICS spacers since using 3/4 PVC material. Perfect fit.

One thing I haven't done on any bike is the main spring spacer. I didn't see much info about that part in the forum here. What is the general idea on how to accomplish that and what's the purpose? My initial thought is to put the spacer at the bottom of the spring underneath the existing spacer (the nylon cylinder with the metal thrust ring on top)? How much pre-load should I use on the main springs?

Lastly, just to make sure I am clear - No need to introduce more float on this system right? Leave the MV stock?

you have enough float for woods, its too much for mx and thats why most modify the mid, the main springs on the 05 yz were 5 mm too short and rattle around, no one knows why kyb did this, any after market stuff is longer to fix the problem. Ktm sell spacers that go on the top of the springs, they may fit the 05 kyb as well.

Ok, thanks MOG. Time to launch. Will report how this works out next week. I hope the racer likes it.

I can testify that a similar build was AWESOME on my own 05 YZ250F. It sucked up high speed square edge hits like a Lexus. I later switched to an 06 YZ250 (2T) for other reasons but man I hated losing that YZF suspension set up. A matching shock re-valve had a lot to do with it of course. On my 06 I did all the Smart Performance mods along with some region-specific tweaks by Allen from ASR4 (Del Taco, Clover, EPNP). Still fine tuning it but it's great so far. Final plan for the 05 YZF below:

**Add 7mm spacer on top of stock ICS springs to relocate free piston.

**Add 6mm spacer to bottom of stock main springs to eliminate 5mm unloaded play

**Remove 6 of the 24 x 12 HS Comp shims

Comp

24 x 12 (11) (Remove 6)

20 x 12

18 x 12

16 x 12

14 x 12

11 x 25

13 x 50

Rebound (Leave Stock)

21 x 12

16 x 12

20 x 12

18 x 12

16 x 12

14 x 12

12 x 12

11 x 25

19 x 1.62

Mid (Leave Stock)

16 x 12

22 x 08 (3)

18 x 08

16 x 08

14 x 08

12 x 30

16 x 12

22 x 42

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