inner cartridge confusion/binding (showa)

[Berm-Saw]

One of my dampers was binding up as I pushed the damper rod into the cartridge. This is what I'm finding, one of the IC springs is longer than the other, and there is restriction in one of the valving holes (don't know what to call it) the ic spring seem to be a large difference in size to me, and I would guess that the smaller valving hole is a culprit in the binding. Check the pics, need opnions on what to do.

[Berm-Saw]

Notice that in the first pic of the valve piston you can see the white towel through the hole, (in the middle of the nut) however on the other piston you can't.

[mog]

Poke out the tissue and the springs should be the same in length,I'm thinking the springs are 2 different rates

Edited April 20, 2016 by mog

[Berm-Saw]

Poke out the tissue and the springs should be the same in length,I'm thinking the springs are 2 different rates

After closer look that shorter spring is deformed in the middle. I would guess this damage if from my cartridges overpressureizing from them stupid synergy seals that don't bleed excess pressure. Do not buy synergy ics seals people!

That's not a tissue in there. Its a perfectly round hole in the middle, just very small. Still am yet to find something small enough to poke in there. I'm now wonder if that isint damaged to now, it was on the same side as the damaged spring side.

[Jon Heron]

 

Still am yet to find something small enough to poke in there.

Go to your local industrial supply or harbor fright store and you can get a torch nozzle cleaner for cheap that will have a wire in it that should fit to clean it out.

Cheers,

Jon

[mog]

You sure it's not grease in there ?

[Berm-Saw]

Well I got that thing poked out whatever it was, and installed new fc 1.61 pressure springs. But the damper rod still feels weird.. When I push the rod into the cartridge slowly there are spots of no resistance, like dead spots or something. When I push the rod into the cartridge fast it's unnotiicable/feels normal. When I was pushing the upper assembly/cap into the cartridge there was les resistance going in opposed to the other side. I'm wondering if the cartridge body is deformed from over pressurization because of the crap synergy seals? I installed them anyway but it bothers me

[mog]

Either air or the tubes are allowing blowby

[Berm-Saw]

Either air or the tubes are allowing blowby

Doubt there is air so I would bet the tube. There any good way to tell if tube is deformed?

[mog]

Measure it externally

[Berm-Saw]

Well it's not the tubes. I swapped compression assembly's from tube too tube and now the other tube does the same thing and the tube with the 'problem' does not. I just ordered a set of used revalved compression assembly's on eBay out of frustration. Weel see what that does.

[mog]

Must be the piston band

[motrock93b]

What fork is this? Are you still running the Synergy ICS piston seals? I had issues with aftermarket piston seals for my Showa 47 TC forks. I never determined the brand, but they were blue dual-lip which were supposed to be smoother and last longer. No such luck. They would not bleed properly, so I just spent a long time playing with oil height until they would barely let the damper rod go fully into the cartridge. I only did this because I was riding the next day and wanted to test a revalve.

The bike felt good for a short time. Eventually, the forks got stiffer. I took them apart and found the blue seals exploded! When compressing the damper rod oil would just gush out the top. I replaced them with OE Showa seals and now things are back to normal. Another TT poster reported the same problem including blown seals.

If you're still using non OE ICS piston seals, I suggest replacing them with OE. OE bleed the cartridge properly, which is very important. Do your damper rods return fully during the bleeding procedure? Mine did, even with the blue seals. Later, I determined there was trapped air in the cartridge, which still creates internal pressure to fully return the damper. My damper rods moved inconsistently when compressed, i believe because of trapped air. It's possible you're experiencing the same symptoms I did, except your seals haven't exploded. My cartridges were not damaged, so yours are probably OK.

No "trick" ICS piston seals! OE only.

Good luck. Please let us know how this turns out.

[Berm-Saw]

What fork is this? Are you still running the Synergy ICS piston seals? I had issues with aftermarket piston seals for my Showa 47 TC forks. I never determined the brand, but they were blue dual-lip which were supposed to be smoother and last longer. No such luck. They would not bleed properly, so I just spent a long time playing with oil height until they would barely let the damper rod go fully into the cartridge. I only did this because I was riding the next day and wanted to test a revalve.

The bike felt good for a short time. Eventually, the forks got stiffer. I took them apart and found the blue seals exploded! When compressing the damper rod oil would just gush out the top. I replaced them with OE Showa seals and now things are back to normal. Another TT poster reported the same problem including blown seals.

If you're still using non OE ICS piston seals, I suggest replacing them with OE. OE bleed the cartridge properly, which is very important. Do your damper rods return fully during the bleeding procedure? Mine did, even with the blue seals. Later, I determined there was trapped air in the cartridge, which still creates internal pressure to fully return the damper. My damper rods moved inconsistently when compressed, i believe because of trapped air. It's possible you're experiencing the same symptoms I did, except your seals haven't exploded. My cartridges were not damaged, so yours are probably OK.

No "trick" ICS piston seals! OE only.

Good luck. Please let us know how this turns out.

After about 3 days straight of trying to get the bogus synergy seals to work I literally took them out and threw them in the garbage. The blue dual lipped ones are synergy btw... That Rob guy seems nice but really should have offered to take them back but he never did...

What would happen to me is the damper rode would still have 2 to 3 inches of travel left but the pressure spring would already be fully compressed. Huge problem! It basicly turned the damper into another spring.

I have oem ones in now and they bleed properly now. My damper rod will not extend fully under the weight of itself. It will just bearly get there if I hold the cartridge airborne tho. That normal? Note I have the lighter pressure springs in.

[motrock93b]

It is normal. The damper rod extends due to the ICS spring pushing the free piston down. As the spring extends, it's pressure on the free piston reduces. It's not uncommon for it to lack enough force to fully extend the rod forcefully. Some preload the spring to improve cavitation resistance. Lighter ICS springs will produce lower internal cartridge pressure and less forceful damper rod extension unless they have more preload. They are commonly used by reputable tuners (FC), so I wouldn't worry too much about this characteristic.

[Berm-Saw]

I've been hearing talk on spring preloading on here. I understand how a shock spring is preloaded with the rings on top for sag purposes. But how is a fork main spring and pressure spring preloaded and why would one want to do it?

[tmsuspension]

If all the components are fresh and not excessively worn you should be able to get the damping rod to extend to topped out easily with no ics preload

[tmsuspension]

If your having issues with stiction or blow by def pull the damping rod/mv assembly and replace bushings but mainly visually inspect inside the cart. Tube. The slightest wear due to poor lubrication over time will render them junk

[motrock93b]

I have oem ones in now and they bleed properly now. My damper rod will not extend fully under the weight of itself. It will just bearly get there if I hold the cartridge airborne tho. That normal? Note I have the lighter pressure springs in.

When I responded that this is normal, I meant it's normal to extend all but about the last 1/16th" after the final full length bleed stroke. I'm referring to 47 TC Showas. The first time I did this procedure I was concerned the rods didn't lightly "thunk" solidly at full extension. There was about 1/16th" of extension I could gently pull to full extension on both cartridges. I talked with four professional tuners, who stated this was normal due to the lack of ICS piston spring force. Other professionals have posted the same on TT. Some specifically mentioned that ICS spring preloading would be required for stock components to provide adequate force for solid, full extension after bleeding. If the rod doesn't nearly fully extend, or actually sucks back inward if it's pulled to full extension, that's a problem. I've dealt with that (re-bleeding or blown free piston seals).

I've never been able to find a good You tube video showing this procedure.

So. I hope I'm not misinformed. My forks have always bled this way.

What do others think?

Edited May 15, 2016 by motrock93b

[mog]

Mine never fully extended