1997 ST1100 (non-ABS) right fork cap won't come off

Joined
Oct 20, 2015
Messages
6
Location
Wellington, New Zealand
Bike
ST1100
Hi all
I'm in the process of changing the fork oil on this bike which I purchased a few months ago, and judging by the look and smell it's the first time since new (100,00km)
The left side was under air pressure and when I took the drain cap off it spurted out about 3m across the garage floor. I've flushed and changed the oil and put the cap back on.
The right fork wouldn't start draining until I pushed the front end down, and the first few teaspoons came out like sludge.
My problem now is that the right cap won't come off. It's fully unscrewed but is under negative spring pressure. When I used a pry bar under the cap lip, it lifted away but sprang back down against the thread when I let go of it.
I have seen comments about some attachment causing issues with one fork but this seems bizarre, the cap stuck to a loaded spring working in reverse...?
Wondering now if the next step is to remove the wheel and see if there's any bolt from underneath the bottom of the fork holding some weird mechanism in place. I don't get it - this fork is the 'plain' one - no ABS and the left fork has the anti-dive mechanism.
As I was typing I realise I might have answered my own question but can anyone please tell me what the hell is in there?

Cheers
 

wjbertrand

Ventura Highway
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Feb 8, 2005
Messages
4,407
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Ventura, CA
Don't pry on it, the cap is screwed to the damper rod on that side. If you slightly compress the forks, the cap will be lifted up past the end of the fork tube. You'll have to wedge an open end wrench in between the spring retainer and the cap to loosen the locking nut whilst twisting the cap with a 17mm hex wrench.


-Jeff
 
OP
OP
BDAKiwi
Joined
Oct 20, 2015
Messages
6
Location
Wellington, New Zealand
Bike
ST1100
What a SOB of a job getting that right fork damper assy back together and compressing the spring! With a bit of help from Mrs Kiwi (third hand) I managed to get it all back together. With new oil, the front end hardly moves back at all compared to the jack-in-the-box it was before. Massive difference, will ride tomorrow when it's light to see how it feels. Prob the rear shock will be all ugly now....
 

Don-STOC237

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76
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Western Nevada
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237
I always used to put a jack under the engine and then slowly lower the front until the cap was clear. Then after the change was done, jack it back up again to close it up.

Best though is to remove the forks from the bike completely (with all that entails) to do the oil change.
 
Joined
Mar 13, 2012
Messages
5,046
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soCal
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'97 ST1100
STOC #
687
What a SOB of a job getting that right fork damper assy back together and compressing the spring! With a bit of help from Mrs Kiwi (third hand) I managed to get it all back together.
A trick I've learned over the years is to hold the damper rod with a strong magnetic pickup tool. You can then compress the spring with one hand, and put that clip back into place with the other hand while also holding the pickup tool. Two fingers on the pickup tool, the other two fingers on the clip, its a little tricky, but do-able. I always have the fork tube off of the bike as well.
 
Joined
Jun 3, 2006
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British Columbia
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2021 RE Meteor 350
A trick I've learned over the years is to hold the damper rod with a strong magnetic pickup tool. You can then compress the spring with one hand, and put that clip back into place with the other hand while also holding the pickup tool. Two fingers on the pickup tool, the other two fingers on the clip, its a little tricky, but do-able. I always have the fork tube off of the bike as well.
Please post a pic of your Popeye sized arms, as there is NO WAY that I can compress that spring to the point needed to insert the keeper, with just one hand. I always get my wife to hold the rod up and insert the keeper, once I bust a gut compressing that spring.
 
Joined
Mar 13, 2012
Messages
5,046
Location
soCal
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'97 ST1100
STOC #
687
Please post a pic of your Popeye sized arms, as there is NO WAY that I can compress that spring to the point needed to insert the keeper, with just one hand. I always get my wife to hold the rod up and insert the keeper, once I bust a gut compressing that spring.
jeez, between this and the garbage disposal thread you guys are giving me a lot more credit than I deserve when it comes to brute strength. I'm about 5'9" and 175lbs, not exactly a bruiser. Next fork oil change I'll shoot a video and send it to you. I back the retaining nut off to make it a bit easier, but that's about all. I do notice that age seems to have a negative effect on muscle strength though, so as I 'mature' to the level of some other members here my technique may have to change.
 

ST1100Y

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637
I've build myself a tool/hook from rigid cloth-hanger wire (more reliable then those magnetic pick-ups) to hold the rod up while pushing spring, spacer and plate down to slide that slotted spring seat underneath the lock nut; a bit tricky though, as simultaneously one has to hold & centre plate and spacer underneath, but I'm with dwalby in that its doable... ensure to wear gloves though, to prevent cutting your (oily) fingertips on any of the parts named or the top edge of the fork tube...
Evolving from this one could actually use a tie-down/strap to suspend above DIY wire-hook from the ceiling, freeing both hands for the task.
And a motorcycle scissor-jack comes really handy to safely raise<>lower the bike's front precisely as needed
(did my first fork rebuild with the oil-pan suspended on a car type, bottle-jack which is not providing fully secure and sturdy support... :roll:)
 

ReSTored

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2019 Tracer GT
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4463
While it's a time consuming hassle I don't think you can drain all the fluid (especially the fluid in the cartridge), then flush with clean fluid, refill the cartridge and then get the fluid levels right on both sides unless you remove the forks. While everything is off and readily accessible you can clean up the brake pads, pistons etc..... and everything else in that area if you are so inclined.
 

RobbieAG

Robert
Joined
Apr 4, 2014
Messages
524
Location
Greensboro NC
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2005 ST1300
I just did the fork oil on my 1100 today. I ended up using a hanger and two helpers (one to hold the hanger keeping the rod up, and one to slip in the clip while I compressed the spring) to get it back together. I think from here on I'll do it when I change front tire and pull the forks.
 
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OP
BDAKiwi
Joined
Oct 20, 2015
Messages
6
Location
Wellington, New Zealand
Bike
ST1100
What a SOB of a job getting that right fork damper assy back together and compressing the spring! With a bit of help from Mrs Kiwi (third hand) I managed to get it all back together. With new oil, the front end hardly moves back at all compared to the jack-in-the-box it was before. Massive difference, will ride tomorrow when it's light to see how it feels. Prob the rear shock will be all ugly now....
Sure enough, once the fork oil was replaced the rear shock was noticeably bouncier. I bought and installed a new Hagon unit, but the front is bouncing again. It's become so bad that I think the damper has failed. Ah well, with winter fast arriving I guess I'll strip the front end completely and start again.
I was sternly educated about suspension setup by Dave Moss when he was in Wellington recently. He could tell I have some mechanical aptitude but also that I was woefully (and given said aptitude, wilfully) under-informed about what really is one of the most important things we can do to keep our bikes shiny side up. Awesome setup advice here:

https://www.youtube.com/watch?v=Ikjw4IheeF4.

My ST doesn't have all the adjustments shown but everything else applies and it really is great advice.


Here's a pic of the top mount of the original shock - that odd sound I thought was the panniers bouncing...
20160121_230346.jpg
 
Joined
Sep 10, 2011
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West Michigan
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'98 ST1100
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8470
If you saw that much sludge, you need to remove the forks and do a thorough cleaning, if you haven't already. I have found that "Simple Green" or a similar household "degreasing fluid" works good. Remove the spring and drain all fork fluid and add the the cleaning fluid. Then pump the fork tube several times. Drain & repeat until the cleaning fluid that you drain looks fairly clean. Then add some transmission fluid and repeat a few times. Then finally add the correct amount of fork oil. Racetech says the fluid level should be 130 mm from the top, with the spring removed and the fork tube fully compressed.

BTW, I have found that using the degreasing fluid works better than MMO ( Marvel Mystery Oil ) and is cheaper.
 
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OP
BDAKiwi
Joined
Oct 20, 2015
Messages
6
Location
Wellington, New Zealand
Bike
ST1100
Agreed Jim, that sludge didn't look like it'd move easy. I did shine a torch down after just an oil flush and they looked pretty clean but yeah, in the next couple of months the whole lot is coming off and I'll completely strip and clean them. I just hope I didn't damage the dampers on my first attempt (when I was using a pry bar to try and see what was keeping it all stuck together).
Interesting about your oil level suggestions, will add factory suggested amount and see if it's different...
 
Joined
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British Columbia
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2021 RE Meteor 350
Interesting about your oil level suggestions, will add factory suggested amount and see if it's different...
ALWAYS use the oil level measuring method when filling the forks. It is the only way to ensure you have the proper amount of oil in there.
 
Joined
Mar 20, 2016
Messages
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Auckland, New Zealand
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2005 ST1300
STOC #
8901
Sure enough, once the fork oil was replaced the rear shock was noticeably bouncier. I bought and installed a new Hagon unit, but the front is bouncing again. It's become so bad that I think the damper has failed. Ah well, with winter fast arriving I guess I'll strip the front end completely and start again.
I was sternly educated about suspension setup by Dave Moss when he was in Wellington recently. He could tell I have some mechanical aptitude but also that I was woefully (and given said aptitude, wilfully) under-informed about what really is one of the most important things we can do to keep our bikes shiny side up. Awesome setup advice here:

https://www.youtube.com/watch?v=Ikjw4IheeF4.

My ST doesn't have all the adjustments shown but everything else applies and it really is great advice.


Here's a pic of the top mount of the original shock - that odd sound I thought was the panniers bouncing...
20160121_230346.jpg
Regarding your front suspension, I have changed the front end of my (formerly Wellington-located) 1990 ST1100 and have so far installed a second right leg damper cartridge into the left leg, in place of the damper rod. I used a set of fork caps off a VFR800 to connect the damper cartridge rod at the top, and the standard right leg spring and spacer. All this is just bolt-in stuff and reversible if I so choose. As a second iteration, I have re-shimmed the cartridges in both legs to add both compression and rebound damping, and also added 15mm to the preload spacers. This made reassembling the springs and washers even more fun!

I am pretty happy with the front end now, if I wanted to set it more to a full-on "sports" configuration I would do some more work to the cartridge valve bodies to reduce the amount of free bleed as this allows a bit of a floating sensation, but that would be a trade-off against the current plushness. Some stiffer straight rate springs are next on my shopping list and increasing the oil height (currently stock) would reduce the dive a little more, but my back shock (OEM, 94000km and only 26 years old) is probably the next weak link to address as I seem to be bashing the undercarriage more often that I should.
 

ST1100Y

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I have found that "Simple Green" or a similar household "degreasing fluid" works good.
If nothing else at hand: 1/2 a pint of petrol/gasoline will work fine too ;-)
One can flush some brake-cleaner after that for rinsing...
The non-ABS forks are great, not requiring removal from the bike due to the drain-bolts at the bottom; ABS-II forks require removal of frond wheel, callipers, fender... the whole party...

As for oil weight:
- on OEM springs I used 10W, maybe a 15...
- with Hyperpro springs I ended up with 7W... 10W was way too harsh on the frostbitten mountain roads, giving one sore wrists and that...
 
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