fork service

Got questions? We got answers....
jbowens2401
Member
Posts: 301
Joined: 08:26 pm Aug 18 2009
Country:

fork service

Post by jbowens2401 »

I will be servicing my forks for the first time on a 2005 kdx 220 before we ride at LBL this weekend. Last time we went, I noticed my front was bottoming out quite a bit. I have some .40 xr 400 springs (I weigh 165 w/o gear) and 1'' sch 40 pvc to make an 8mm preload spacer. I am going to set my oil height at 100mm and remove 2 large shims. I have quite a bit of havoline atf type f...is this okay to use for fork oil or do I need to get something else. Any advice on setup or tips for doing the job are greatly appreciated.

Thanks,

John
User avatar
Indawoods
Creator and Founder
Creator and Founder
Posts: 9951
Joined: 09:59 am Jun 12 2003
Country:
Location: Midwest

Post by Indawoods »

I only use fork oil in the forks. I don't trust the viscosity of ATF but you may be OK....
*** Administrator //***
****'95 KDX 200/****

"People ate cows a thousand years ago for the same reason we eat them now. Cause they are easy to catch.We're not savages,we're just lazy. A cheetah could taste like chocolate heroin. But will never know. Those bastards are fast!!! "
michael
Member
Posts: 66
Joined: 12:17 am May 29 2010
Country:
Location: australia

Post by michael »

The atf will expand alot when it heats up, so theoretically they will get stiffer, due to a reducing air gap....
KarlP
Supporting Member III
Supporting Member III
Posts: 1484
Joined: 02:26 pm Jun 29 2005
Country:
Location: Alabama

Post by KarlP »

The short job would be to just change fluid and springs. I think I'd do that and see how it felt before removing shims.

If the fluid is still the OEM stuff you'll be making a BIG change just replacing that.
'08 KTM200xc
'99 CR/KDX Hybrid with that RB stuff done to it
KX100 for the boy
jbowens2401
Member
Posts: 301
Joined: 08:26 pm Aug 18 2009
Country:

Post by jbowens2401 »

KarlP,

Thanks for the feedback. I'm only going to change the springs and oil for now and see how I like it before messing with the shims. I'll be happy to have the proper springs and fresh oil in there.

Inda,

On the way home, I bought some 5 and 10 wt motul fork oil. I may give the ATF a shot next time.

I may have some other questions once I start the process. (I do have the service manual, so hopefully it won't be too difficult.

Thanks for the help,

John
User avatar
OLHILLBILLY
Supporting Member I
Supporting Member I
Posts: 286
Joined: 08:34 pm Feb 10 2009
Country:
Location: S. W. Missouri

Post by OLHILLBILLY »

>|QBB<[/url]
jbowens2401 wrote: I may have some other questions once I start the process. (I do have the service manual, so hopefully it won't be too difficult.
It's not. I made the 2 "special tools" at work..
Image

Then it was a piece 'a cake to change the springs and oil. Shop manual covers the process pretty well. The main thing I had to pay attention to was figuring the length to cut the spacer material to, to get my desired pre-load. Other than that, nothing to it.
2004 KDX 200.. Coupla mods
2009 KX250F.. Track Star
2007 Hayabusa.. Street Madness
jbowens2401
Member
Posts: 301
Joined: 08:26 pm Aug 18 2009
Country:

Post by jbowens2401 »

inda,

i read on another post how you reccomend determining the lenght of the preload spacer made of pvc. I couldn't grasp how far to let the outer tube pull up before I dropped the pvc in to mark it for cutting. When I let the forks extend fully, I was getting a preload spacer the same lenght as stock and I even used the longer xr 400 springs. can someone point me in the right direction and help me determine how long my preload spacer should be.

thanks,

john
User avatar
Indawoods
Creator and Founder
Creator and Founder
Posts: 9951
Joined: 09:59 am Jun 12 2003
Country:
Location: Midwest

Post by Indawoods »

5-8mm preload minus the cap thread and lip depth. That's what it should be....

Make sense?

What you can do... is mark the PVC right at the top of the forks... then measure the caps thread and lip depth and subtract the difference to get 8mm of preload... that will let you know how much to cut off....
Last edited by Indawoods on 11:26 pm Aug 03 2010, edited 1 time in total.
*** Administrator //***
****'95 KDX 200/****

"People ate cows a thousand years ago for the same reason we eat them now. Cause they are easy to catch.We're not savages,we're just lazy. A cheetah could taste like chocolate heroin. But will never know. Those bastards are fast!!! "
jbowens2401
Member
Posts: 301
Joined: 08:26 pm Aug 18 2009
Country:

Post by jbowens2401 »

with the new springs in place and the cap screwed down all the way on the rod...there is no space between the bottom of the cap and the top of the spring....in all the posts i've read there is space there and thats how you calculate the preload. I'm confused.
User avatar
Indawoods
Creator and Founder
Creator and Founder
Posts: 9951
Joined: 09:59 am Jun 12 2003
Country:
Location: Midwest

Post by Indawoods »

Pics say a thousand words... Can you post a few?
*** Administrator //***
****'95 KDX 200/****

"People ate cows a thousand years ago for the same reason we eat them now. Cause they are easy to catch.We're not savages,we're just lazy. A cheetah could taste like chocolate heroin. But will never know. Those bastards are fast!!! "
User avatar
Indawoods
Creator and Founder
Creator and Founder
Posts: 9951
Joined: 09:59 am Jun 12 2003
Country:
Location: Midwest

Post by Indawoods »

Are your new spings the same length as your old springs with the spacer? If not... sumpin is up...
*** Administrator //***
****'95 KDX 200/****

"People ate cows a thousand years ago for the same reason we eat them now. Cause they are easy to catch.We're not savages,we're just lazy. A cheetah could taste like chocolate heroin. But will never know. Those bastards are fast!!! "
jbowens2401
Member
Posts: 301
Joined: 08:26 pm Aug 18 2009
Country:

Post by jbowens2401 »

Not sure (I didn't check). I ordered the springs from moto sport. They are OEM honda 2000 xr400 springs. They had the right part numbers on the packaging that I found on the parts fiche at moto sport and bike bandit. I looked at it a bit more and there was a tiny amount of free space between the top of the spring and the bottom of the cap when it was screwed completly down on the rod (the holder nut was screwed down as low as possible also). I knew the xr400 springs were way longer than stock but I still expected to see a little more free space. Anyway, I ended up with 8.5mm pvc spacers to acheive a 5-6mm preload (I hope). I mixed 5 and 10 wt motul and filled it up to 4 inches free space which is a little over 100mm. I haven't put the forks back on the bike yet, but pushing down on them when they are on the ground they seem to make a slight clanging noise. I took both caps off and made sure to screw the forks onto the caps but I still get the same noise. Is this normal or could something else be going on. Sorry about not getting up any pics, my camera is not working right now. Also, I appreciate the help. Time for bed...got to take the kids for their first day of school tomorrow.

Thanks,

John
User avatar
Indawoods
Creator and Founder
Creator and Founder
Posts: 9951
Joined: 09:59 am Jun 12 2003
Country:
Location: Midwest

Post by Indawoods »

Did you twist the tubes onto the caps? You have to do it that way to avoid binding up the springs during assembly.

You can't twist the caps on the the tubes....
*** Administrator //***
****'95 KDX 200/****

"People ate cows a thousand years ago for the same reason we eat them now. Cause they are easy to catch.We're not savages,we're just lazy. A cheetah could taste like chocolate heroin. But will never know. Those bastards are fast!!! "
jbowens2401
Member
Posts: 301
Joined: 08:26 pm Aug 18 2009
Country:

Post by jbowens2401 »

I did twist the tubes onto the caps, so that should be okay. When I cut the PVC spacers I used a hack saw and it was late so they aren't perfectly flat. Now that I've got my spacer lenght, I'm going to cut some new ones with pvc cutters to ensure they will sit flat. I dont think they are sitting flat against the washers and this is causing the springs to rub the inside of the fork leg during its travel. Do you think that could be a posibility?

Thanks,

John
User avatar
Indawoods
Creator and Founder
Creator and Founder
Posts: 9951
Joined: 09:59 am Jun 12 2003
Country:
Location: Midwest

Post by Indawoods »

Sure do... That would push on the springs on one side... causing contact with the tube walls....
*** Administrator //***
****'95 KDX 200/****

"People ate cows a thousand years ago for the same reason we eat them now. Cause they are easy to catch.We're not savages,we're just lazy. A cheetah could taste like chocolate heroin. But will never know. Those bastards are fast!!! "
jbowens2401
Member
Posts: 301
Joined: 08:26 pm Aug 18 2009
Country:

Post by jbowens2401 »

I got the new preload spacers installed and that stopped the claning. Now I just need to get the forks back on the bike. On the fork installation thread, I noticed there were a few opinions on torque specs for the top and bottom clamps. What do you reccomend. I have the manual, so should I just use the factory specs.
User avatar
Indawoods
Creator and Founder
Creator and Founder
Posts: 9951
Joined: 09:59 am Jun 12 2003
Country:
Location: Midwest

Post by Indawoods »

On stock forks.... use the recommended torque specs in the manual.
*** Administrator //***
****'95 KDX 200/****

"People ate cows a thousand years ago for the same reason we eat them now. Cause they are easy to catch.We're not savages,we're just lazy. A cheetah could taste like chocolate heroin. But will never know. Those bastards are fast!!! "
jbowens2401
Member
Posts: 301
Joined: 08:26 pm Aug 18 2009
Country:

Post by jbowens2401 »

Inda,

I got everything installed on the bike using service manual instructions and torque specs. When I sit on the bike and pull in the front brake to compress the front forks. It feels like there is a small catch in the first 1/2 inch or so of the travel then it smooths out and springs back up into position smoothly. Is something wrong or is this normal. I think I remember it doing the same thing before I changed the springs and all was stock then. Any information is greatly appreciated.

Thanks,

John
User avatar
Indawoods
Creator and Founder
Creator and Founder
Posts: 9951
Joined: 09:59 am Jun 12 2003
Country:
Location: Midwest

Post by Indawoods »

You are probably feeling the 2 piece rotor slipping in the rings.... it's normal....
*** Administrator //***
****'95 KDX 200/****

"People ate cows a thousand years ago for the same reason we eat them now. Cause they are easy to catch.We're not savages,we're just lazy. A cheetah could taste like chocolate heroin. But will never know. Those bastards are fast!!! "
jbowens2401
Member
Posts: 301
Joined: 08:26 pm Aug 18 2009
Country:

Post by jbowens2401 »

cool, is that also known as a "floating disc"...it seems like i've seen that somewhere on here? Also, I would like to thank you for all of your help. We are going to LBL this weekend, so I'll get a good opportunity to test it out. I'll post a report on the new fork springs next week. If anyone wants to go to LBL, they are more than welcome. We are going to get there around 5 on Friday afternoon and stay til about noon on Sunday.

Thanks,

John
Post Reply