Loss of Damping, Forks

Joined
Feb 22, 2010
Messages
21
Location
Washington State, Skagit County
Bike
'91 ST1100
About 3k miles ago I replaced the stock springs with Progressive springs and installed as per the instructions, no problems and I was enjoying the new setup. I have been running 8 wt. in the forks and things seemed alright. A few days ago I was entering the freeway and heard a pop/thump from the front end and found I had no spring dampening left. Lots of spring travel, no visible loss of oil, the anti-dive still works. Any ideas what might be the issue here? I won't have any time to get things apart for a look in the near future so I thought I would throw this out there for comment and see what show up :) 91 non-abs 1100
 

John OoSTerhuis

Life Is Good!
Joined
May 10, 2005
Messages
5,218
Location
Bettendorf, Iowa
Bike
1991 SSMST1100
STOC #
1058
Sounds to me like your damping rod unscrewed from the fork cap. You won't know for sure until you get in there.
+1

Shouldn't take more than 20 minutes to check that out. The manual calls for 10.5mm of threads on the top of the rod for the fork cap to screw onto (204 in lbs).

John
 
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Samdoggy
Joined
Feb 22, 2010
Messages
21
Location
Washington State, Skagit County
Bike
'91 ST1100
Yeah, that's an easy one to check, thanks! Do you guys normally use threadlock on that one? I had to go 400 miles yesterday and two mountain passes and it sure was interesting! Might be able to get something that simple done today, hopefully that is the problem.
Thanks for the input, time to get out the torque wrench.
 

John OoSTerhuis

Life Is Good!
Joined
May 10, 2005
Messages
5,218
Location
Bettendorf, Iowa
Bike
1991 SSMST1100
STOC #
1058
Per the service manual, no thread lock, hold the lock nut with a 14mm open-end wrench, and torque the fork cap against the nut. Clearly shown in the schematic highlight.
 
Joined
Jun 3, 2006
Messages
3,512
Location
British Columbia
Bike
2021 RE Meteor 350
I've never been able to assemble that rod, spring and keeper without four hands - my two compressing the spring, with my wife sliding the keeper into place with one hand while her other hand is holding the damn rod up by a wire to keep it from falling back into the fork. It is a bear of a job for me to get that spring compressed enough and it seems there has to be a better way. I back off the lock nut to the end of the rod while doing this, which helps get that keeper in there a bit easier. I'd love to see how they do it in the factory.
 
Joined
Mar 13, 2012
Messages
5,046
Location
soCal
Bike
'97 ST1100
STOC #
687
I've never been able to assemble that rod, spring and keeper without four hands - my two compressing the spring, with my wife sliding the keeper into place with one hand while her other hand is holding the damn rod up by a wire to keep it from falling back into the fork. It is a bear of a job for me to get that spring compressed enough and it seems there has to be a better way. I back off the lock nut to the end of the rod while doing this, which helps get that keeper in there a bit easier. I'd love to see how they do it in the factory.
I use a strong magnetic pickup tool to hold the rod from falling, and try to hold it between two fingers. I compress the spring with the other hand, and with the other two fingers on the magnet hand I try to slide the clip back into place. I've been successful sometimes with this technique, and depending on my patience I sometimes have to call the wife out to put the clip in. I put so few miles on my bike these days its been a while since I've been in there, so my memory isn't perfect regarding my success rate.
 
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Samdoggy
Joined
Feb 22, 2010
Messages
21
Location
Washington State, Skagit County
Bike
'91 ST1100
Yeah I used the magnetic pen to grab the rod as well, after a number of tries and a walk around the house to calm down I finally got it. I find that I do better the second time around on a lot of things :) Trouble is that once you get the hang of it you won't ever have to use that skill again. Well, for a while anyway. By then I usually forget about what the trick was. Thanks to everyone for your input, I have found this forum and its' members to be a treasure trove of good information and sometimes entertainment! Oh- one other thing, what is the best oil to use? lol
 
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Samdoggy
Joined
Feb 22, 2010
Messages
21
Location
Washington State, Skagit County
Bike
'91 ST1100
Fixed! I ended up welding a nut onto a piece of rod and used that to grab the damping rod and haul it out, after that just a matter of compressing the spring enough to get the keeper and washer back on and then thread on the cap. Front end feels normal again, ready to ride once more :) thanks for all the good ideas, ride safely.
 
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