Stiff forks after seal & oil change on CR 250 -99

[nylundm]

Yesterday I finished seal and oil replacement on my Honda CR 250 -99. This was my first time working on Showa forks.

Anyhow the seal replacement was done correctly (as far as I can tell) and the oil level was 180cc in "innertube" and 373cc in "outertube", I used 10W motorex fork oil.
Fork assembly to the tripleclamps was also checked for the alignment.

Well ... then the problems started.

When I pushed the handlebars, forks did not compress well only few centimeters (one inch), alltought they did compress when I tried them before assembly to the tripleclamp.

Before I started to panic I opened the air screws and some air whistled out. Then I started to pump the forks multiple times and opening the air screw. Everytime the forks got softer and air was coming out of airscrews.

The forks are still stiff but traveling about 2/3 of the lenght of the forks.

So help me out guys. Did I do some mistake by chosing too stiff oil or messing up the assembly or is this normal effect after oil seal & oil change?

My plan was to ride easily for few laps and come to the pits and let the air out again from the forks for a couple of times. I really hope that this could be the remedy.

I have also read that the forks has to be broken down, does this apply only to the new bikes or does it apply also in this case?

-Mikael

 

[Layton]

You may have assembled the wheel to the forks incorrectly which causes the fork tubes to bind.

Loose the axle clamps, push down on the bars several times, then retighten the axle clamps.

Can't hurt anything and might help.

 

[shockdoc]

Do as Layton said too but, 10 wt. oil is not going to work very well. Redo them with 5 wt. & they should feel better.



doc

 

[Mully]

Now that brings up a good question.

What is the proper way to align the front wheel before you tighten everything up ?? I was told that with the bike on a stand (at least the front wheel off the ground) to get everything finger tight, spin the front wheel, and then hit the front brake and hold it untill everything is tightened down. Anyone else ??

Mully

 

[CRPilot]

I'll go out on a limb and ask an important question on the rebuild. After filling the inner chamber and tightening the caps, did you pump the shaft several times to force the air through the valve? After all the air was worked to the top did you compress the shaft fully and blow off the excess oil from the inner chamber? If not the forks would be very stiff until it was done. It would also explain why each time you work the forks farther, you have to release the air pressure.

I've run 10wt before and noticed they were stiffer, but not what you are describing.

Just a thought...

 

[my250]

use this URL http://www.mx-tech.com/downloads.asp

it will help w/showas - rebuild and the fork installation

 

[nylundm]

Thx guys for the answers.

Originally posted by CRPilot
I'll go out on a limb and ask an important question on the rebuild. After filling the inner chamber and tightening the caps, did you pump the shaft several times to force the air through the valve? After all the air was worked to the top did you compress the shaft fully and blow off the excess oil from the inner chamber? If not the forks would be very stiff until it was done. It would also explain why each time you work the forks farther, you have to release the air pressure.

Well ... I did not pump the shafts. I guess that it's stiffness is caused by the excess air in the forks.

But the question remains ... do I have to open up the forks again and take the air out or does it come out by opening up the air screws after few laps and repeating this procedure few times?

-Mikael

 

[JTT]

Mikael, call me overly cautious, but I would probably take them apart again, just to make sure everything is how it's supposed to be. Look at it as practice for the next rebuild ;) Following the instructions from MX Tech you should be good to go. :thumb:

Mully, as for your question. I used to follow the bounce/brake routine, but now do it slightly different. I install the front axle, and tighten the axle nut. Then with the axle clamps loose, grab the lower fork leg. You will see you can move it ever so slightly on the axle with just your hand. Wiggle it until it finds it's "natural" location and tighten. This way you know for absolute sure that everthing is free and not binding.