1994 ABS 1 model fork question

Erdoc48

Erdoc48

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Joined
Jan 25, 2009
Messages
280
Age
62
Location
Myrtle Beach, SC/ Sometimes Colorado
Bike
94/00/04 STs, FSC600
Prior owner put Progressive springs and I assume measured spacers (prior owner used wire conduit which was undamaged on inspection) in as well as 15 wt fork oil. I had the forks rebuilt in 2022 with Honda OEM parts due to seal leak (so new seals and bushings and now have 10 wt fork oil). I also noted an ongoing braking head shake (mild but annoying- also present for the time I’ve owned the bike)- switched out new rotors and brake pads and broke them in the other day (fixed that shake as I guess my OEM rotors may have had some hot spots on them). Bike rides well and all seems good but when you’re hard on the front brake nearly at a stop (like 5 mph or less), it seems like there’s a little clunk/looseness in the front end (felt, not audible)- I increased my fork oil just a bit, like 10 ml which should = 10 mm fluid rise and increased the preload on the springs with a new PVC spacer of 10 mm additional (thinking maybe when the garage rebuilt the forks, they measured by volume and not mm level). It’s always made the little clunk since I’ve owned the bike but I can’t seem to get rid of it. No leaks at the anti-dive valve and it has new steering head bearings (tapered roller- adjusted properly) as well for the past 10K miles or so (wheel bearings replaced when the wheels were powder coated in 2018) and feel normal when I had the wheel off recently as well (nice and smooth, no grit). Has anyone else had this and had a reasonable fix for it? Other than what I mentioned, it brakes, handles, and hits bumps just fine, stays straight and zero drama. I have learned to live with it, I guess, but want to see if anyone has any ideas- I searched the forum (as well as the net, but I only see anti-dive as applies to GoldWings) but there’s not a lot regarding the ST1100 forks. My 2000 doesn’t do any of this (and has the OEM setup with stock springs and the original bushings/ seals, as well as 5 wt oil - Amsoil Shock Therapy).

Sorry for the lengthy read, I just want to put as much information as is needed.
 
a little clunk at low speed could be the anti-dive unit, or possibly the steering stem bearings.

you said the bearings were replaced 10k miles ago, did you ever re-tighten them after installing them? They can potentially seat themselves in more fully over time and loosen up a bit, easy enough to try to tighten them up a bit and see if it makes any difference.

As I recall, the anti-dive sometimes clunks, sometimes doesn't, depending on the conditions. So if you're consistently feeling the clunk the steering stem bearings might be the more likely culprit.
 
Erdoc48 said:
Sorry for the lengthy read, I just want to put as much information as is needed.
Click to expand...
Paragraphs are your friend. Anything greater than about five lines is difficult for the eyes. To wit:


Prior owner put Progressive springs and I assume measured spacers (prior owner used wire conduit which was undamaged on inspection) in as well as 15 wt fork oil. I had the forks rebuilt in 2022 with Honda OEM parts due to seal leak (so new seals and bushings and now have 10 wt fork oil).

I also noted an ongoing braking head shake (mild but annoying- also present for the time I’ve owned the bike)- switched out new rotors and brake pads and broke them in the other day (fixed that shake as I guess my OEM rotors may have had some hot spots on them).

Bike rides well and all seems good but when you’re hard on the front brake nearly at a stop (like 5 mph or less), it seems like there’s a little clunk/looseness in the front end (felt, not audible)- I increased my fork oil just a bit, like 10 ml which should = 10 mm fluid rise and increased the preload on the springs with a new PVC spacer of 10 mm additional (thinking maybe when the garage rebuilt the forks, they measured by volume and not mm level).

It’s always made the little clunk since I’ve owned the bike but I can’t seem to get rid of it. No leaks at the anti-dive valve and it has new steering head bearings (tapered roller- adjusted properly) as well for the past 10K miles or so (wheel bearings replaced when the wheels were powder coated in 2018) and feel normal when I had the wheel off recently as well (nice and smooth, no grit). Has anyone else had this and had a reasonable fix for it?

Other than what I mentioned, it brakes, handles, and hits bumps just fine, stays straight and zero drama. I have learned to live with it, I guess, but want to see if anyone has any ideas- I searched the forum (as well as the net, but I only see anti-dive as applies to GoldWings) but there’s not a lot regarding the ST1100 forks. My 2000 doesn’t do any of this (and has the OEM setup with stock springs and the original bushings/ seals, as well as 5 wt oil - Amsoil Shock Therapy).
 
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Erdoc48 said:
Interesting…how would something like that happen? Did you just replace the fork or did you figure out a fix for it?
Click to expand...
Computrac Atlanta - who rebuilt all of my ST1100 forks - found it with one pair they were rebuilding (I had 3 sets done).
I had heard the clunk for a while but never figured it out.
When he 'reverse' micrometered them before rebuilding one set, the dial moved up very visibly when the feet got down to that point.
The only 'fix' was to buy a pair of new lowers which I later sent to him so he could finish that set.
I appreciated his honesty as he could have just rebuilt them and I would have never figured it out.
But he took the time (I was in the shop) to sit down and show me what the issue was.
When I bought the 4th ST1100 runner, I shipped him those folks so he could rebuild them also.
 
Thanks for all of the replies…I was thinking about getting a replacement set of lowers, but they’re all going to be used and of ndeterminate mileage/condition. As for the steering head bearings, I have adjusted them from time to time, but another adjustment may be helpful (and it’s relatively easy to do).

I was thinking the anti-dive as well as a culprit but as the only parts available are the O-rings, there’s not a lot replaceable otherwise, meaning the piston and other parts are NLA. It is something I might have to live with but at least I can check the steering head bearings as a potential.
 
Erdoc48 said:
Thanks for all of the replies…I was thinking about getting a replacement set of lowers, but they’re all going to be used and of ndeterminate mileage/condition. As for the steering head bearings, I have adjusted them from time to time, but another adjustment may be helpful (and it’s relatively easy to do).

I was thinking the anti-dive as well as a culprit but as the only parts available are the O-rings, there’s not a lot replaceable otherwise, meaning the piston and other parts are NLA. It is something I might have to live with but at least I can check the steering head bearings as a potential.
Click to expand...
When Computrac Atlanta redid my forks, the Racetech stuff pretty much replaced the anti-dive stuff IIRC.
 
Postscript:
I figured in general everyone likes to know how things turned out…it was my steering head bearings that just needed a little tightening (by about 3/4 turn). All good with the clunking and didn’t take long to get the top triple clamp off and tighten (I have tapered bearings so a lot is by feel as 20 ft lbs torque specified will basically lock the bars in place)- this took ~ 30 minutes.

But…I noted a small weep from my right posterior fork near the seal. Ugh…what solved this is (and I originally thought no way it would work), was a Seal Mate tool. I was really careful in its use and took the 94 out just now, and no more leak/ weep. I will keep an eye on it, of course, and got new OEM seals, dust seals and the metal clips from Partzilla (which will go with the rest of the bike parts I have for when they’re needed). The 2000 uses the same parts (and never had the fork seals changed but has been fine from that standpoint).

I figured the Seal Mate was a $10 gamble and although it may have been considered ‘snake oil’, it actually did work, so ‘I’m really pleased with that’.

If I need to change the seals, of course, I will, but now that it’s hot in the South, I want to put any work on the bikes off for a long as possible until the cool weather of the fall.
 
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what weight oil did you end up using?
will there be a significant difference between 7w and 15w
what about after market oils
 
Actually it’s Lucas branded synthetic fork fluid, 10 weight (I will likely change it in the near future as it now has maybe 20K miles on it). On the other 2 bikes, I use 5 weight Amsoil ‘Shock Therapy’. All run great now and the clunk in the 94 is gone (just tightened the needle roller bearing nut just a bit, not too tight). For my 2000 ST with the stock front suspension, the 5W fluid works very well- handles well and isn’t hash at all. Different fluids despite the same viscosity may behave a little differently. 15w might give a harsh ride. You could try it and change it if you don’t like it, but likely stick with 10w for the ST. Unfortunately there’s no right answer, some like a softer more compliant ride (me) and others want the bike to ride and handle like a race bike.
 
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