1995 cr 250 killer head shake

[axidentprone]

I have a 95 cr 250and at high speeds the head shake will scare the hell out of you. It will happen even on a gravel rode or driving on a slightly bumpy flat, and its not under braking. I don't ride mx its more of a hillclimber/trail driver. race sag is 4 inches front comp=11 rebound 14.rear comp 17 rebound 17. Just a tad softer than stock. I really need to soften this bike up so it doesnt deflect whenever i hit a little bump, and help stability(turning really isn't that important to me).1 Do i need to increase the forks height above the triple clamps or decrease it for more stability?.(any guesses on a starting point?) 2 I would also like to hear what other people use for compression and rebound dampening settings for trail riding. and what would be a good fork oil height or would it matter. or if increasing my race sag would help.

 

[chainsaw]

Is the rim bent?

 

[dbrace]

Was your chain loose?

 

[cr25096er]

you need to push the forks down in thwe clamps. make the caps flush w/ the top of the clamp. i have a 96cr250 and i have the clickers all the way out, seemed to help. sag is at 100mm and forks are flush w/ the clamps. how does shock adjustment effect headshake?

 

[MX2_motorex]

Make sure your forl seals aren't blown

 

[DWreck]

The old steel framed CR's (92-96) have a tendency to do this. They turn well but the price you pay is headshake. Careful suspension set up can help lessen this and like CR25096er said pushing your forks down flush in the clamps and making sure your ride height (sag) is proper will also help.

 

[axidentprone]

i started turning all the comp and rebound clickers out, but i wasn't sure about rebound is it better to turn it all the way out or leave it some place in the middle. i already turned the compression screw on the forks out about 21 clicks. no the rim is not bent as far as i can tell but decreasing compression and rebound does help to keep headshake from initiating.One of my friends told me to do the oppisite and increase the amount of fork extending from the top of the triple clamps to increase weight on the front end but i think he might be confused.

 

[motometal]

you are on the right track.  I would recommend turning the compression all the way out (especially on the forks).  Rebound you want to leave fairly close to stock.  You may want to consider running the fork oil level on the low side for woods--this will make the forks more compliant in the mid stroke.  I would say 10-20 ccs less than standard on each side (but who knows where the fork oil level is set right now).  I thought the forks on this bike were pretty stiff and harsh, to really get optimum performance you would probably need a re-valve for the woods.

Put the rear sag at 100 mm then find a good rough woods loop to ride, and adjust the rebound a click or two stiffer, than a click or two softer, see where you like it best.  Don't forget where you started, and work with either the forks or shock-don't try adjusting both at the same time.

have fun!

 

[axidentprone]

thanks for the help. I just got in from hill climbing. damn that thing is rough going across any kind of rough flat. I weigh about 160 what would happen if i loosend up the rear spring and increased sag. right now i'm going to go adjust the fork height like u said

 

[MONKEYMOUSE]

Rember. . .you can only be testing one thing (variable) at a time. . .think back to science class lol.

 

[john stu]

increasing the sag (lowering the rear)to the minimum recomended will help as will putting the forks flush in the clamps also softer compresion settings and try different rebound settings as wheel if the rebound is too slow the forks might be packimg (not extending back out before the next bump) i had the same bike a factory connection revale helped a lot

 

[MrMXer327]

I had one and it will work well once setup properly.
Forks:
-First thing you want to do is set the oil level to 100mm. The lower level will help with mid-stroke harshness and reduce headshake.
-Next, Set the forks 5mm from the top of the cap to the top of the triple clamp.
-Next, set the compression at 14 and rebound at 12 out from full hard. Make 2-click adjustments from there until you get the feel you are looking for. Only change one at a time. (The fork really needs to be re-valved.)

Shock:
I ran my sag at 105mm. Start with the compression and rebound at 10 clicks out from full hard.
Now your ready to ride - Make sure you body positioning is correct and consistent as you tune the suspension. Be constant with the throttle and brake too. If it is time to be on the gas... stay on the gas. Do not wick it open... then chop the throttle... then wick it open again. This will upset the chassis. As you tune, Make notes after each adjustment.
-Find a single square edge bump and go-slow at first, but slowly work up some speed as you hit it. Begin adjusting the compression softer until the bike does not deflect off the bump. Next, Find a corner that has some good acceleration bumps, adjust the rebound so that the rear of the bike does not pack down in the stroke, and begin to deflect. Now it is time to move to breaking bumps. (Make sure you keep your weight back under braking or the rear will deflect and headshake will be increased) You want the front to be firm, but not deflect off the breaking bumps. If fork is deflecting, you need to have a good feel for where it is in the stroke. Install a zip tie on the fork leg as a guide to tell you how far in the stroke the fork has traveled. Now make 2 click adjustments to the compression note the zip tie location and how the bike reacted. Repeat the same with the rebound adjuster. After awhile, you will see a pattern develop and get a feel for what is really happening as you make changes. There is a whole lot more to tuning, but this should get you started.
Oh yea, One more thing, the 95CR loves the effect of rear brake dragging. Try is out sometime. Find a rough section and go though without dragging the rear brake.... Now go though that same sections and apply just a little rear brake.

 

[axidentprone]

I love this forum. thanks for the help. right now i have it so the top of the fork(not the top of the fork cap) is level with the triple clamps can any harm be done by pushing the forks down so the top of the cap is level with the triple clamps? I really don't know much about revalving. Is there any thing i can do, I know that some forks have shims that can be adjusted. How much does revalving cost? funds are extremely limited. and finally is 100 mm for distance from the oil to the top right. i know the minimum amount is 499 cc's but i'm not sure what distance that is in mm from the top. i know i could buy a steering damper for a quick fix if i wasn't broke.lol. thanks

 

[MrMXer327]

I wouldn't recommend lowering the tubes below the fork cap.
The method I use to set the fork oil level is as follows:
Remove the fork spring and fully collapse the fork.
Using a Turkey Baster with a hose slid over the end, remove the oil to a level that is 100mm below the top of the collapsed fork leg. Raise the outter fork tube up to allow the oil caught between the outside tube and inside tube to flow back into the inner tube. Collapse the fork and repeat the process until no more oil is drawn into the Turkey Baster.

 

[cr25096er]

john stu how did the revalve effect it and how much was it? i ride pits,woods and i jump a bit so could a revalve help?(my bike is a 96cr250)

 

[motometal]

increasing your rear sag (so the bike sits lower) is worth a try, but keep in mind that the compresion dampening is postion sensitive, so it is very possible for the rear to be more harsh when adjusted for more sag.  More sag will definitely help headshake, you may also check out the position of the rear axle, if it is towards the front of the adjustment range you could install a chain with one more link, making the wheelbase longer and the bike more stable.

 

[john stu]

the revlave was $160 for the forks and $160 (factory connection)for the shock and it made a big differance the head shake was a little less than half of what it was stock and the bike had about the same bottoming resitance as stock but was much plusher in the small stuff it was worth it at the time i just paid $5000 for a new bike whats another $320 to make it handle way better.your bike might be more money to get done now because it probly will need bushings and seals that my bike did not need seince it was new (2 months old at the time)

 

[motometal]

you've got my vote.  I've ridden many CRs and I just remember the '95 having harsh, stiff suspension, even for mx.  A good suspension shop can make it plush no problem.  Shipping and waiting is kind of a pain though, any shops within driving distance that are good at revalving?

 

[MrMXer327]

AMEN !

 

[cr25096er]

wer isnt far from me. its in nj but across the state. would that be a good place to get the forks done? i know its for woods but could i still jump w/ the wer suspension?

 

[woodsy]

I didnt read all the responses to this one so if I am being redundant pardon me..
What width of bar are you running? Real narrow bars (setup for the woods) can create headshake. I have found that anything under 29 1/2 for me is a headshake waiting to happen.
Just a thought...
Woodsy

 

[cr25096er]

ill have to check that.