1710 replies to this topic

[rpxtreme03]

i seems to me like your low speed shims are missing in your base valve..i would probably first change your mid to something more progressive. like
2-20.1
18.1
3-17.1
16.1
as for your front end going wide. speed up your rebound in your forks a click or two. your front end is likely staying compressed to long and not forcing it back up and out as you come out of the corner. try going a click or two softer on the rebound. if that doesnt work you might try raising your forks in the clamps to get a little more weight in that front end..its really hard to give you a good stack for both of these extremes.have you tried a click or two softer on the lsc and perhaps raising oil hight for bottoming resistance.

[MXandSXracer21 TT Silver Member]

He has a single stage stack in his base valve, which is why you are not seeing the low speed shims that you are accustomed to seeing.

[mynewcr250 TT Silver Member]

rpxtreme03, on 27 April 2012 - 06:54 PM, said:

i seems to me like your low speed shims are missing in your base valve..i would probably first change your mid to something more progressive. like
2-20.1
18.1
3-17.1
16.1
as for your front end going wide. speed up your rebound in your forks a click or two. your front end is likely staying compressed to long and not forcing it back up and out as you come out of the corner. try going a click or two softer on the rebound. if that doesnt work you might try raising your forks in the clamps to get a little more weight in that front end..its really hard to give you a good stack for both of these extremes.have you tried a click or two softer on the lsc and perhaps raising oil hight for bottoming resistance.

as mxandsxracer21 referenced, the early 20mm showas in the cr250's (and i believe thedogger said the 02-03 crf's used the 20mm as well?) seemed to only use a single stage stack with minimal shims due to this small piston. the 01 cr250 i think uses the same exact stack except adds 1- 20.1 and uses an 8.2 as a clamping shim instead of the 9.2 that my 2000 uses. the peen was still there and there was no evidence of grinding so AFAIK it is a stock base valve stack.

as far as bottoming resistance goes, its good now. what im after is not loosing it with valving changes but still getting a softer set up.

for your midvalve suggestion, should i do that stack, but try for a .25mm float versus the .20 that i got stock? i was going to just try removing a single 20.1 from the mid valve first, but that would put me at .30 which from what ive read here is not a float to aim for with the type of riding im doing?

edit: anxious to ride this weekend, so the forks got fresh fluid, i put the mid back together stock, but i took the 17.1, 15.1, and the 13.1 from the base valve and reverse stacked it under the 9.2 just to try it out this weekend.

Edited by mynewcr250, 27 April 2012 - 08:55 PM.

[rpxtreme03]

the 20.1 drop is always a good way to soften your low speed. the only problem you might have with that large of a float is it may feel harsh in the midstroke. i tried a 35mm float once and it was so soft in the lsc that when it finaly hit the hsc it felt harsh because the forks were already moving so fast. the removal of the 17.1,15.1 and 13.1 i would not recomend for what you want to do. these are hsc shims that will likely cause a loss in you bottoming resistance. i think what you are looking for is something more progressive with a softer lsc and while keeping your hsc for that bottoming resistance.

[theDogger TT Gold Member]

MyNewCR250....I sent you a PM with some info and my number, sorry I have not gotten back to you sooner...busy building a new Track..

theDogger

[theDogger TT Gold Member]

Showa/KYB Shock Bleeding Procedure

Make sure that all adjusters are full soft and that the rebound rod is pushed down in the shaft. Once all parts are cleaned, pistoned faced and shaft fully assembled fully submerg them in oil. I prefer to use a ratio rite cup. Bang it around to get as much oil in and air out as possible.

*If your preload is set correctly measure the lenght of the spring and record that number. You will be happy that you did later.

1. With the shock in a vise w/ soft jaws, file reservoir with oil

2. Cupping you hand over the reservoir to create pressure to force the oil through the transfer port to the shock body side.

3. Once you have filled the reservoir side ¾ of the way, put a lightl coat of seal grease the edge of the bladder on the inner and outer lips.

4. Slowly push the bladder in while excess oil will over flow.

5. Insert the gutter ring

6. Inflate the bladder with 100psi of air.

7. Tap the shock body lightly with a rubber mallet to help push any trapped air into the shock body from the transfer port. (Majority of the air should move once the bladder is hit with air)

8. Fill the shock body up with oil (1/2” from completely full.)

9. Now quickly transfer the shaft to the body and quickly push it ½ way down into the oil, now take your rubber mallet tap the shaft down the remaining way and let it sit for approx. 10-15min to allow the oil to settle and what ever air that came oout to dissapate. (Again you can lightly tap the shock body to help release trapped air bubbles.)

10. Top the oil off in the body side to within 1/4" of the top

11. Slowly pull the shaft up taking care not to move to fast so a vacuum is not created behind the piston causing cavitation..

12. Run the shaft through the stroke 10-15 times and then compress the shaft 3/4 down in the stroke and left it sit for 10-15min.

13. Repeat the previous step until all air has been removed.

(How can you tell the difference between air and the piston band sliding in the shock body? Air in the body sounds like rice crispys in milk with the shaft is moved through the stroke, when it is clear of air it will sound like two peices of paper sliding against eachother)

14. Slowly release all air from the bladder

15. After releasing the air from the bladder top off the shock body with oil

16. Slowly push the seal head in letting it bleed (You will notice on the side of the seal that there is small bleed hole)

17. Put the gutter ring clip in.

18. Air the bladder until the seal head seats itself (15-20psi)

19. Make sure that the shaft is fully extended

20. Slowly release all air from the bladder again.

21. Now position the shock in the vise so the the HSC adjuster is parrellel to the ground.

22. (All air must be removed from the bladder) Slowly remove the HSC adjuster and submerge it in oil

23. Slowly Air the bladder with 60psi of air.

Now this is where you get the very last remaining air out of the shock. Now up until this point if you have blead the shock correctly no air should show up. But there is always a huge blubble hidding in the shaft. The wire method does not help with this and this is where all the air is left.

24. Gentle tap the clevis downward in the rebound stroke with a rubber mallet -Watch for air to come out. You should see a couple good size bubbles.

25. Very slowly run the shaft through the stroke several times being careful on the rebound stroke to make sure that the reservoir port remains submerged in oil and does not suck air. (You are going to loose oil keep it topped off)

26. Once convinced that all the air is out, Slowly remove the air from the bladder while adding oil in the HSC Adjuster hole until level with the top of the HSC Adjuster hole

27. Insert the HSC Adjuster and slowly screw it in allowing air to escape.

28. Air the bladder back up with the desired amount of Air or Nitro.

29. Check to make sure that the shaft runs through the complete stroke.

30. Measure the free length of the spring and subtrack the pre-loaded total you took eariler This will give you the measurment for the correct pre-load. But still best to check it once in the bike to make sure that the sag is correct.

30. You are done.

Bleeding the shock is not easy, but as with anything the more you do it the easier it will get. For those that are new to this it may not make sense at first but after a few tries it will.

Troubleshooting:

Issue #1: When trying to bleed the shock there is no resistance and once complete the shaft will not fully extend.

Cause: 99% of the time the piston was installed upside down or incorrect face shim size.

Issue #2When trying to bleed the shock it is very difficult to run the shaft through the compression stroke.

Cause: Check to make sure that all the circuits are open and that the rebound rod is bottomed out.

Issue #3: After finishing the bleed the shaft will not fully extend.

Cause #1: Bent Shaft
Cause #2: Air in the shock
Cause #3: Rebound clicker not set to fully soft.
Cause #4: Shock body is under-filled


theDogger

Edited by theDogger, 28 April 2012 - 07:18 AM.

[erik_94COBRA TT Bronze Member]

Dogger-

Any chance you can take a look at my post in the Suspension forum?

http://www.thumperta...03-honda-cr250/

I'm ready to make some changes, if required.

Thanks,

Erik

[theDogger TT Gold Member]

Sent you a PM

theDogger

[MRW TT Gold Member]

Wow! Great post on the Showa/KYB Shock Bleeding Procedure Dogger!! Love learning new things here on TT!

Edited by MRW, 18 May 2012 - 11:53 AM.

[MXandSXracer21 TT Silver Member]

Finally put the shock bleeding procedure to use. What a breeze! I still used the wire method to plunge the shaft into the shock body at the beginning, but I still ran the shock shaft through it's strokes as specified by the directions. I think the wire method allows for less messiness and allows a bulk of the initial air to escape. I also had the Low-friction shock ring that allowed the shock shaft to go through the strokes smoother. I also used Factory Connection GSF 2.5 wt. Shock oil since the local bike shop didn't have any Maxima 3 wt in stock.

Using 160 psi of air (rebound and compression clickers on full soft), the time it takes to fully extend from full compression is just under 4 seconds. I attribute this lower time to the MX-Tech Low Friction Piston Ring. Before I re-tore down the shock, I was getting almost 6 seconds to full extension (however, I was using fresh Maxima 3 wt. shock oil instead of the 2.5 wt FC shock oil that is used this time).

I will be installing the shock this weekend and will take it for a spin either this weekend or next. I will report on the piston ring afterwards. As well as comparing my stiction zones between the newly rebuilt shock with the piston ring and the shock I have on my bike right now.

Edited by MXandSXracer21, 23 May 2012 - 07:13 PM.

[theDogger TT Gold Member]

FYI and for what its worth there are 3 or 4 oil manufactures that distribute suspensin oil. They see it to the companies and add color to it and brand it there own!

theDogger