Author Topic: Fork oil replacement level  (Read 590 times)

0 Members and 1 Guest are viewing this topic.

Offline Wantabeach

  • Bicycle
  • *
  • Posts: 91
  • AREA: South Central Area
  • COG#: Forum
  • Membership Level: Forum Subscriber
Fork oil replacement level
« on: September 29, 2019, 02:43:24 pm »
So i just installed new sonic forks and 10 weight oil.  Don’t like the dampening at all and want to try 20 weight.  I really don’t want to pull the forks off and would prefer to suck the oil out abut not sure how I will measure the replacement oil since forks should be fully collapsed for mine. Is there a measurement i could use with forks fully extended that would get me to the same place?
2006 Kawasaki Concours
2006 Harley Heritage (sold)

Offline connie_rider

  • "OtP" {retired/assistant} Slave Labor
  • I Need a Life
  • ******
  • Posts: 9900
  • Help us make "OtP" possible! "AGAIN"
  • AREA: South Central Area
  • COG#: 4154
  • Membership Level: Asst. Area Director
Re: Fork oil replacement level
« Reply #1 on: September 29, 2019, 02:57:12 pm »
Damping is normally rebound damping, not compression damping.
Are you having a front end dive problem or a rebound damping problem?

Completely compressed front without fork removal can be done on the center stand, with a little preparation.
ie; Secure the center stand with a strap so that it cannot accidentally collapse.
     Put a small jack under the headers to support the bike.

Process;
     Remove caps and springs.
      Be aware that front end "will" compress as soon as caps are removed.
      The jack will help prevent that.
      Then, Remove caps and springs.
      Lower with the jack, or (if too tall) Have someone help you lower the front end.
      Suck out oil and add new.
      Raise the front again.
      Then, install caps and springs.

NOTE: If you want to go to the next step, we've found inexpensive Fork Emulators (about $35) that can (relatively) easily be installed in your forks. Makes damping adjustable... (rebound and compression)
     
Ride safe, Ted
14 Connie (Traveler II) / 03 Connie (Buddy)
Gone but not forgotten; 87 and 00 Connies..

If your not already a COGger, "consider becoming one".
Help us make "OtP" possible again!!

Offline Wantabeach

  • Bicycle
  • *
  • Posts: 91
  • AREA: South Central Area
  • COG#: Forum
  • Membership Level: Forum Subscriber
Re: Fork oil replacement level
« Reply #2 on: September 29, 2019, 07:40:51 pm »
Where did you find those emulators?  The Rachtec ones are pricey. Do I need special tools to install?. I heard the hardest part was drilling out the damping tubes.  Is separating the tubes hard? 

Thanks
Paul
2006 Kawasaki Concours
2006 Harley Heritage (sold)

Offline bajasam

  • Scooter
  • ***
  • Posts: 282
  • AREA: Southwest Area
  • COG#: Forum
  • Membership Level: Forum Subscriber
Re: Fork oil replacement level
« Reply #3 on: September 29, 2019, 08:04:55 pm »
Only non-typical tool is the one to get your damper rod out, easy to make with some rebar and 5/8 nut if you have a little welder. check Ebay for 41mm emulators for harley's, I think I paid 37 bucks for mine.

Offline Wantabeach

  • Bicycle
  • *
  • Posts: 91
  • AREA: South Central Area
  • COG#: Forum
  • Membership Level: Forum Subscriber
Re: Fork oil replacement level
« Reply #4 on: September 29, 2019, 08:39:03 pm »
I thought folks just drilled the rod out. Does one need to remove the rod to drill it? 

Thanks
paul

« Last Edit: September 30, 2019, 01:30:26 am by Wantabeach »
2006 Kawasaki Concours
2006 Harley Heritage (sold)

Offline Bud

  • Crotch Rocket
  • ****
  • Posts: 1882
  • AREA: North Central Area
  • COG#: 12907
  • Membership Level: Active
Re: Fork oil replacement level
« Reply #5 on: October 01, 2019, 10:05:26 am »
I thought folks just drilled the rod out. Does one need to remove the rod to drill it? 
Thanks
paul
All that is done is to add more holes so that the damper rod has little to no effect.  The damping is then done by the emulator valve.

2005 Kawasaki Concours
2001 Kawasaki Concours
1982 Suzuki GS1100GK
1983 Honda GL650I SilverWing

Offline cra-z1000

  • Sport Tourer
  • *****
  • Posts: 2061
  • Keeping it upright..
  • AREA: South Central Area
  • COG#: 9790
  • Membership Level: Active
Re: Fork oil replacement level
« Reply #6 on: October 01, 2019, 10:36:13 am »
So i just installed new sonic forks and 10 weight oil.  Don’t like the dampening at all and want to try 20 weight.  I really don’t want to pull the forks off and would prefer to suck the oil out abut not sure how I will measure the replacement oil since forks should be fully collapsed for mine. Is there a measurement i could use with forks fully extended that would get me to the same place?

What year is your bike ? The first gen models have a drain screw at the bottom .
1987 C 10
80 Kawasaki KZ 1000 MK 2
74 Honda 750 four ss
73 Suzuki 550 triple
72 Honda 550 four

Offline connie_rider

  • "OtP" {retired/assistant} Slave Labor
  • I Need a Life
  • ******
  • Posts: 9900
  • Help us make "OtP" possible! "AGAIN"
  • AREA: South Central Area
  • COG#: 4154
  • Membership Level: Asst. Area Director
Re: Fork oil replacement level
« Reply #7 on: October 01, 2019, 02:03:32 pm »
I thought folks just drilled the rod out. Does one need to remove the rod to drill it? 

Thanks
paul

Wantabeach, You never answered my question about front end dive or damping?
  ie; What problem are you having?

Yes, the fork must be disassembled/rod removed to drill it out.

If you opt to go to the inexpensive Fork Emulators, most of us added a couple of small holes in them too.
  {There are discussions in the Forum that go into more detail about those small holes and the adjustments that others used}
Even though they may sound daunting, all are EZ to do. {but do require a little mechanical knowledge}

Ride safe, Ted
« Last Edit: October 01, 2019, 05:35:44 pm by connie_rider »
14 Connie (Traveler II) / 03 Connie (Buddy)
Gone but not forgotten; 87 and 00 Connies..

If your not already a COGger, "consider becoming one".
Help us make "OtP" possible again!!

Offline Lee

  • Road Bike
  • ***
  • Posts: 318
  • AREA: South Central Area
  • COG#: 12558
  • Membership Level: Active
Re: Fork oil replacement level
« Reply #8 on: October 01, 2019, 04:21:51 pm »
Not daunting at all. One special tool you make yourself for a few coins out of nut and bolt or if you do not have a long socket extension 4 bolts and threaded rod. Youtube is full of how too! Good luck!

Offline connieklr

  • Crotch Rocket
  • ****
  • Posts: 1189
  • AREA: Northeast Area
  • COG#: 1608
  • Membership Level: Active
Re: Fork oil replacement level
« Reply #9 on: October 01, 2019, 08:41:09 pm »
Damper Rod Holder:





Double-nut the ends, tack weld if you have the equip., or a good friend that does.

This is from a KLR fork, but the Connie uses the same size holder.

171mm fork oil level from the lip of the tube to the top of the oil, spring out, fork fully compressed.



« Last Edit: October 01, 2019, 08:50:54 pm by connieklr »
________________
Guy Young
COG #1608
COG Life Member
Semi-Civilian
GB Young Services, LLC

Offline Wantabeach

  • Bicycle
  • *
  • Posts: 91
  • AREA: South Central Area
  • COG#: Forum
  • Membership Level: Forum Subscriber
Re: Fork oil replacement level
« Reply #10 on: October 06, 2019, 02:23:34 pm »
So i just installed new sonic forks and 10 weight oil.  Don’t like the dampening at all and want to try 20 weight.  I really don’t want to pull the forks off and would prefer to suck the oil out abut not sure how I will measure the replacement oil since forks should be fully collapsed for mine. Is there a measurement i could use with forks fully extended that would get me to the same place?

What year is your bike ? The first gen models have a drain screw at the bottom .

Mine is a 2006....so got to suck it out or remove tubes and drain.
2006 Kawasaki Concours
2006 Harley Heritage (sold)

Offline Wantabeach

  • Bicycle
  • *
  • Posts: 91
  • AREA: South Central Area
  • COG#: Forum
  • Membership Level: Forum Subscriber
Re: Fork oil replacement level
« Reply #11 on: October 06, 2019, 03:00:24 pm »
I thought folks just drilled the rod out. Does one need to remove the rod to drill it? 

Thanks
paul

Wantabeach, You never answered my question about front end dive or damping?
  ie; What problem are you having?

Yes, the fork must be disassembled/rod removed to drill it out.

If you opt to go to the inexpensive Fork Emulators, most of us added a couple of small holes in them too.
  {There are discussions in the Forum that go into more detail about those small holes and the adjustments that others used}
Even though they may sound daunting, all are EZ to do. {but do require a little mechanical knowledge}

Ride safe, Ted

I was having trouble with dampening.  Since I weight 225#, i was having trouble with drive before changing to the sonic 1.1 springs.   That said, I don’t think i spent enough time settling up sag until now. I’m currently on a trip in Taos and in preparation, I work hard to setup the sag and rear shock dampening for my current load.  Now, the bike fells level and working together front to back and very stable and predictable. Further, i would describe it as performing like my son Eric’s 1992 Concours (mine is 2006) with air assisted front forks: firm and bumpy on rough roads.  Night and day better then when I first crafted this post.  I may still want to experiment with oil weight or emulators.

Regarding oil weight, the guy at Sonic told me that increasing oil weight overloads these dampening rods pretty quick and when people say their ride seems harsh it’s because they used a heavy weight oil which basically locks up the dampening at some point and makes it feel rough. That’s why I went with 10 vs 20 weight oil.  My guess that’s why many change to emulators when they just can’t get the dampening and ride to feel right. 

Question: anyone at my weight found improved dampening with stock dampening rods installed going with heavy oil?  If so, how much do you weight, what springs do you have and what weight oil worked for you?

Thanks
Paul
2006 Kawasaki Concours
2006 Harley Heritage (sold)

Offline bajasam

  • Scooter
  • ***
  • Posts: 282
  • AREA: Southwest Area
  • COG#: Forum
  • Membership Level: Forum Subscriber
Re: Fork oil replacement level
« Reply #12 on: October 06, 2019, 03:18:24 pm »
I'm at 250#, went with 1.2 springs and the ebay emulators, added 4 extra holes to damp rod and 2 extra holes to emulator valve, topped off with 20 weight(some have used 40w) everything seems great so that's where it'll stay for now.No more brake dive at 80mph thank god.

Offline connie_rider

  • "OtP" {retired/assistant} Slave Labor
  • I Need a Life
  • ******
  • Posts: 9900
  • Help us make "OtP" possible! "AGAIN"
  • AREA: South Central Area
  • COG#: 4154
  • Membership Level: Asst. Area Director
Re: Fork oil replacement level
« Reply #13 on: October 06, 2019, 04:27:16 pm »
I admit; I'm a newbie at Suspension.
I've tried to understand by reading a lot about suspension settings and asking questions [then I did a lot of trial and error].
 
Below is what I opted to use on the front of my C-10 and why.....
NOTE: I mostly used settings developed by Steve Sefsick.

I'm about 220, and my Nephew (sometimes rides the bike) is about 250.
We wanted the capability to adjust the preload. {ability to set Sag [at approx. 35mm] when either of us ride the bike}.
Instead of buying aftermarket, I opted to use the OEM springs {4" removed from tightly wound section of the springs, and installed a 4" spacer}. 
  {The 4" removal adds stiffness, they work great, and are Cheap err Frugal.}
      I ride with no additional preload.
      He rides with about 1/2" of preload cranked in.

Fork Damper Valve {ie; Inexpensive Emulators} installation; ($48.50)
https://www.ebay.com/itm/41mm-Fork-Damper-Valves-TC-88-Softail-Touring-Dyna-FXST-FLST-FXDWG-FLT-2000-UP/172661938134?epid=671622052&hash=item28337417d6:g:q48AAOSw2GlXD-PA
      I added 3 holes to the Valve. {control low speed Compression damping, may assist control of low speed rebound damping}
           Don't recall exact size of the new holes, but they are slightly smaller than the original 1 hole.
       The original 2 holes in the dampener rod are now 6 ea. (5/16" dia) holes. {Extra holes moves all damping control to the Fork Damper Valve}
       I used ATF {primarily for rebound damping control}, set level at 6 1/4" from top (with forks collapsed). {higher fluid level helps reduce dive}
       NOTE: ATF is a {approx. 10-15wt} "anti foaming" hydraulic Oil. {Same type fluid as Fork Oil [see Frugal above] }
                 Installation of a Fork Damper Valve does not change rebound damping, therefore, adjustment of rebound damping is made by changing the oil viscosity.
        Spring preload on Damper valve is set at 2 turns. {for high speed Compression damping}

Below is the discussion about the Fork Damper Valves we used.
http://forum.cog-online.org/tiressuspension-c10/inexpensive-emulators/msg655861/#msg655861

NOTE: Post #5 has a great "step by step" explanation from Racetech on how Emulators work.  :great:
           It takes a bit of study to understand, but it is well worth the read.
                https://www.racetech.com/HTML_FILES/DampingRodForks.HTML

Ride safe, Ted
« Last Edit: October 13, 2019, 09:52:54 pm by connie_rider »
14 Connie (Traveler II) / 03 Connie (Buddy)
Gone but not forgotten; 87 and 00 Connies..

If your not already a COGger, "consider becoming one".
Help us make "OtP" possible again!!

Offline Wantabeach

  • Bicycle
  • *
  • Posts: 91
  • AREA: South Central Area
  • COG#: Forum
  • Membership Level: Forum Subscriber
Re: Fork oil replacement level
« Reply #14 on: October 16, 2019, 04:58:26 pm »
Damper Rod Holder:





Double-nut the ends, tack weld if you have the equip., or a good friend that does.

This is from a KLR fork, but the Connie uses the same size holder.

171mm fork oil level from the lip of the tube to the top of the oil, spring out, fork fully compressed.

So the 15/16 nut fits the concours? 

How long should the tool be top to bottom nut?

I don't have a welder and don't know how.  How about some JB Weld as a substitute?

So the purpose of the tool is to hold the top of the dampening rod stable while one unscrews the rod from the bottom of the slider? 

I see some videos of folks loosening and tightening the rod while the spring is tight but i guess you don’t really want to spin anything and must be able to torque properly.

Paul
« Last Edit: October 16, 2019, 05:05:17 pm by Wantabeach »
2006 Kawasaki Concours
2006 Harley Heritage (sold)

Offline Lee

  • Road Bike
  • ***
  • Posts: 318
  • AREA: South Central Area
  • COG#: 12558
  • Membership Level: Active
Re: Fork oil replacement level
« Reply #15 on: October 16, 2019, 06:14:37 pm »
No welder? No problem. Just use four nuts, two on either end of all thread tightened against each other. Length is not so important. You can also use a bolt and two nuts turned against each other with some tape to hold if you have multiples of socket extensions. Yes on to hold and torque to spec or loosen allen bolt.

Offline Wantabeach

  • Bicycle
  • *
  • Posts: 91
  • AREA: South Central Area
  • COG#: Forum
  • Membership Level: Forum Subscriber
Re: Fork oil replacement level
« Reply #16 on: October 16, 2019, 06:27:16 pm »
No welder? No problem. Just use four nuts, two on either end of all thread tightened against each other. Length is not so important. You can also use a bolt and two nuts turned against each other with some tape to hold if you have multiples of socket extensions. Yes on to hold and torque to spec or loosen allen bolt.

Ahh....yes....that makes sense. 

Do you know if I can drill out the dampener rods by just holding them in a vice and use a hand drill? 
2006 Kawasaki Concours
2006 Harley Heritage (sold)

Offline connie_rider

  • "OtP" {retired/assistant} Slave Labor
  • I Need a Life
  • ******
  • Posts: 9900
  • Help us make "OtP" possible! "AGAIN"
  • AREA: South Central Area
  • COG#: 4154
  • Membership Level: Asst. Area Director
Re: Fork oil replacement level
« Reply #17 on: October 16, 2019, 07:57:44 pm »
Yes, you can use a hand drill and a vise. The hole locations are not critical.
I suggest center punch where you want to do the holes, drill smaller holes, then enlarge all 6 to 5/16".

The additional holes are added only to increase flow in that area.
This increase, moves the damping control from the 2 stock holes to the Damping Valve/Emulator.

Ride safe, Ted
14 Connie (Traveler II) / 03 Connie (Buddy)
Gone but not forgotten; 87 and 00 Connies..

If your not already a COGger, "consider becoming one".
Help us make "OtP" possible again!!

Offline Boomer

  • Crotch Rocket
  • ****
  • Posts: 1164
  • Wickford, UK
    • Boomers GTR Site
  • AREA: Northeast Area
  • COG#: Forum
  • Membership Level: Forum Subscriber
Re: Fork oil replacement level
« Reply #18 on: October 17, 2019, 10:13:01 am »
If you are rebuilding the forks you can use a wooden broom handle.
Just cut one end to a square taper and jam it in there.
That will hold the damper rod enough for you to undo the Allen bolt that holds it in place.
It's also enough to tighten and torque the bolt when re-assembling.
Yes, I have a "special tool" a friend welded up and ground for me, but before that I did 2 fork rebuilds using the broom handle method.  :great:

The emulators are the way to go.
I'm 400lbs and my C10 just couldn't cope even with Sonic 1.2Kg springs and 20W oil.
I now have the emulators and 20W oil and the front feels planted and smooth, but no longer floaty or jolting.
Not as good as the front end on my C14, but way better than the stock suspension.

George "Boomer" Garratt
Wickford, UK
CDA-007


Offline Lee

  • Road Bike
  • ***
  • Posts: 318
  • AREA: South Central Area
  • COG#: 12558
  • Membership Level: Active
Re: Fork oil replacement level
« Reply #19 on: October 17, 2019, 01:51:48 pm »
Boomer

how much brake dive do you have?

what level did you set your oil?

how many turns on emulators?

thx!

Offline Boomer

  • Crotch Rocket
  • ****
  • Posts: 1164
  • Wickford, UK
    • Boomers GTR Site
  • AREA: Northeast Area
  • COG#: Forum
  • Membership Level: Forum Subscriber
Re: Fork oil replacement level
« Reply #20 on: October 18, 2019, 06:47:33 pm »
My RaceTech Emulators are at 2 turns with 4 holes using the yellow springs.
Dive is about 2" under heavy braking but way less than without the emulators.
Oil is at the recommended level, but am considering lowering it by half an inch to see if it improves the ride.
« Last Edit: October 18, 2019, 06:50:38 pm by Boomer »
George "Boomer" Garratt
Wickford, UK
CDA-007


Offline Lee

  • Road Bike
  • ***
  • Posts: 318
  • AREA: South Central Area
  • COG#: 12558
  • Membership Level: Active
Re: Fork oil replacement level
« Reply #21 on: October 20, 2019, 07:24:48 am »
Thx Boomer!