ST1300.us.com  

Go Back   ST1300.us.com > Honda ST1300 Forums > Maintenance & Repair > Suspension

Reply
 
Thread Tools Display Modes
Old October 30th, 2008   #1
CGRedRed
Forum Supporter
 
CGRedRed's Avatar
 
Join Date: Oct 2008
Location: Anaheim, CA
Posts: 229
Rep Power: 114 CGRedRed is on a distinguished road
Default Fork Compression Damping Adj.

After fiddling with fork damping combinations for about a year, I am unable to announce any magic cures to what I feel is poor fork action, but IMHO some ride improvement can be made by a reduction of compression damping. I have adjusted rebound damping by changing fluid weight rather than mess with that part of the cartridge assembly. if you are into tinkering, a good first step is to disconnect either damping rod to evaluate what an instant 50% reduction in damping feels like. I did this a year ago and really liked the result. Now, after many other trials, I am back to this configuration in my ST1300. What about asymmetric damping forces, you say? Don't worry about it. The ST1100 has it and some racers have done it. That rigid fork assembly can't tell the difference.
To adjust compression damping, remove the cartridge assembly by unscrewing the usual bolt found in the bottom of the slider. (these bolts are apparently torqued less than in non-cartridge forks, as bolt removal didn't even require an impact wrench)

Photo 1 shows the damper assembly. Use a screw driver blade to pop off the aluminum oil lock piece.The bright aluminum thing exposed is the end of the cartridge. To remove it rap it firmly with a plastic or other soft hammer, driving it into the damper housing. Next, using a suitable pick, remove the internal snap ring and using the damper rod push the cartridge back out of the housing.

Place the cartridge in a vise with plastic or wood jaws and loosen the allen bolt Over a towel or the like, disassemble the cartridge as shown in Photo 3
which shows the cartridge turned 180 degrees from Photo 2.(whoops) Take care to lay out everything in order of assembly. The thick black thing in the center is the valve body and to its right is the shim stack. Looks like an ordinary washer, but there are seven sliver-thin shims hiding there. Remove up to 6 to reduce compression damping. My tech advisor tells me that you must have at least one in place to prevent backflow through the valve and loss of all rebound damping. Photo 4 shows the half-assembled valve with shims laid out.
Finally, reassemble the cartridge assembly, hand tightening the allen bolt to "snug". Reinstall in damper body, insert and seat snap ring, and use damper rod to drive cartridge into assembled position. (Photo 1) Reinstall oil piece and assembly in slider and you're done. I found the old retainer bolt washers (copper) to seal perfectly with a little dab of Permatex, although I had new ones handy.
Attached Images
File Type: jpg ST13Cart1.jpg (42.5 KB, 301 views)
File Type: jpg ST13Cart2.jpg (52.0 KB, 294 views)
File Type: jpg ST13Cart3.jpg (78.8 KB, 292 views)
File Type: jpg ST13Cart4.jpg (73.7 KB, 292 views)

Last edited by CGRedRed; October 31st, 2008 at 12:36 PM. Reason: Correction of errors
CGRedRed is offline   Reply With Quote
Old October 30th, 2008   #2
zldrider
Chief Bottle-washer
 
zldrider's Avatar
 
Join Date: Jun 2008
Location: Redmond, WA
Posts: 4,650
Rep Power: 3 zldrider will become famous soon enough
Default Re: Fork Compression Damping Adj.

You should think about submitting this to our Farkle Article contest. With a bit more work, it could be a "contenda". ;-)
__________________
Joe Zulaski
Redmond, WA
MSF RiderCoach
STOC# 929, IBA# 218

zldrider is offline   Reply With Quote
Old October 31st, 2008   #3
LEINADEUGAL
Donators
 
LEINADEUGAL's Avatar
 
Join Date: Oct 2008
Location: Frelighsburg,Quebec,Canada
Posts: 651
Rep Power: 118 LEINADEUGAL is on a distinguished road
Default Re: Fork Compression Damping Adj.

Tanks ,CGRedRed ... this is a great information on , how to adjust compression damping. (Clapping )This is going to be helpfull on our "Quebec's roads "

Making "OEM" better ...is call fine tuning .It is amazing sometimes ..what you can achieve whith minor investment,and a lot of will,and time.The kind of stuff I like to mess whith ... in our long winter season.The result always make you forgot howmuch trouble you went thru ...and shearing it whith others is also a pleasure,dont you think?

I also beleave ... that Joe is right about submitting this to the Farkle Article contest.

LEINADEUGAL

Last edited by LEINADEUGAL; September 6th, 2012 at 09:27 AM.
LEINADEUGAL is offline   Reply With Quote
Old April 5th, 2011   #4
burt8810
Donators
 
Join Date: Oct 2008
Location: NE Ohio
Posts: 97
Rep Power: 112 burt8810 is on a distinguished road
Default Re: Fork Compression Damping Adj.

Hi,
I have (I think) attached a pdf file with a question about this procedure.
You have done a good job with the article.

Thanks
Herb '03
Attached Files
File Type: pdf Fork valve question.pdf (15.8 KB, 29 views)
__________________
STOC# 8171 AMA# 372640
burt8810 is offline   Reply With Quote
Old April 5th, 2011   #5
CGRedRed
Forum Supporter
 
CGRedRed's Avatar
 
Join Date: Oct 2008
Location: Anaheim, CA
Posts: 229
Rep Power: 114 CGRedRed is on a distinguished road
Default Re: Fork Compression Damping Adj.

Herb, what looks like a single washer in the upper exploded photo is the 7-piece shim stack shown below in the same relative position. I tried a lot of variations, including removing all except one shim (the minimum required to allow the valve to function properly) None of my trials yielded any dramatic improvement, so I gave in and installed the Race-Tech kit. Damping is good, but the ride quality, whether because of shortened wheelbase or whatever, remains far more "nervous" than my ST1100's ride. You can affect rebound action greatly by altering the fork oil weight, which also affects compression damping, of course, so the choice of shims and oil weight theoretically should give you the ride quality you desire. Good luck.
Tim Shevlin Anaheim, CA #1183
CGRedRed is offline   Reply With Quote
Old April 5th, 2011   #6
Wjbertrand
ST guru
 
Wjbertrand's Avatar
 
Join Date: Oct 2008
Location: Ventura, California
Posts: 1,865
Rep Power: 130 Wjbertrand will become famous soon enough
Default Re: Fork Compression Damping Adj.

Tim, I've done the Race Tech mod for both the front and rear suspension. I also have Sonic springs up front and a 1200 Race Tech (Eibach) spring at the rear. 5wt redline synthetic fork oil, and I believe Race Tech puts 5 wt. fluid in the shock when they re-valve it.

With this set up my ST13 is very reminiscent of my ST1100 whilst running at highway speeds, i.e. much calmer and less busy. It's particularly improved the tendency to hobby-horse less over expansion joints. I will admit a more noticeable change from the front than from the rear compared to OEM
__________________
-Jeff-
Ventura, CA
STOC 025
2005 ST1300A
2015 ST1200

The original ST1100 LiST is at www.st-riders.net
Wjbertrand is offline   Reply With Quote
Old April 5th, 2011   #7
CGRedRed
Forum Supporter
 
CGRedRed's Avatar
 
Join Date: Oct 2008
Location: Anaheim, CA
Posts: 229
Rep Power: 114 CGRedRed is on a distinguished road
Default Re: Fork Compression Damping Adj.

Jeff, I should have mentioned that with all the Race Tech goodies, my bike is superb at, oh, 60 mph on up. At 30-45 mph on a smooth road it still feels a little bouncy to my tender butt, but this may be a necessary compromise (to attain good high-speed stability) caused in part, I suspect, by the shorter wheelbase.
Recently I decided to try Mobil 1 ATF in my commuter-bike ST1100 forks. This stuff stiffened up the front end (was 10 weight) enough to make its ride quality very close to that of the ST1300, so in switching from one bike to the other, I don't notice the difference in ride quality that was so apparent with the formerly-softish forks in the ST1100. For my kind of riding (touring-sport) both bikes are just fine and I am all done with suspension upgrades.
Now, on to the adjustable-height center stand project......
Tim
CGRedRed is offline   Reply With Quote
Old June 23rd, 2017   #8
the goodfellow
New Member
 
Join Date: May 2017
Location: Southampton
Posts: 1
Rep Power: 0 the goodfellow can only hope to improve
Default Re: Fork Compression Damping Adj.

Hi all

It's now a long time since the original post, but I've just done this job and noticed something that hasn't been mentioned down the years...

The 7 shims (boy, are they thin!!) in the stack come in 3 slightly different diameters. I think there are 2 of the large size, 3 of the medium and 2 of the smallest.

This next bit is the main reason I'm writing this...

When you come to re-assemble the damper, group the shims together by size with the smallest shims closest to the socket-headed bolt, then medium and finally large. There's probably a witness mark on one of the largest shims to help you get it right too...

If you put them back in the wrong order, things won't work as they should.
the goodfellow is offline   Reply With Quote
Reply

Bookmarks

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump


All times are GMT -7. The time now is 11:49 AM.


Powered by vBulletin® Version 3.7.2
Copyright ©2000 - 2017, Jelsoft Enterprises Ltd.
Copyright 2004-2011 ST1300.US.COM