More Prog spring/fork setup help please!!

[jimmyenglish]

Hi everyone, so I'm trying to relieve the insane stiffness from the front end on my 86' that I've just mildy overhauled. I'm having a hell of a time dialing this in

 

I have Progressive springs and the block of plates from Skydoc. I've dissassembled everything and there is no binding with the forks whatsoever. One thing I find very curious is, even with the forks hanging in the air and no wheel attached, they are VERY hard to compress. Even the weight of the bike barely compresses them. They decompress fine. THen, when I drain the oil out, they slide perfectly. I'm starting to wonder if I need to put the AD's back on? I just returned from a 3500ish mile ride so I think the springs are broken in. I don't think it's a matter of too much oil because a lot of it blew out in the first 100 because I guess I put the 13.5 oz in and that's too much? Also, when I drained each leg, maybe half cup came out of each.

 

Irony is, I go for a ride on my 1975 Kawasaki S3 w/horribly pitted forks and ancient springs and it is a FAR smoother ride. Yeah, it's mush but smooth.

 

What could I be missing here? Thanks!

Edited September 21, 2012 by jimmyenglish
more info

[Trader]

How much preload did you put in? That is determined by the length of the spacers at the top

 

I don't know about the number of oz. but the oil should be something like 4" from the top (with the springs in)

 

Someone can jump in and make correct what the distance from the top should be.

[Prairiehammer]

Put the anti-dive units back on. Don't hook them up electrically. See what that does.

[Snaggletooth]

Hey John,

 

So back to the forks again eh.

 

First, reinstalling the AD's won't change the situation. It sounds like a mechanical or hydrualic issue.

 

So, if you can, can you post pics of the dissembled fork components in the order they were installed and maybe a pic of each item close up? It's got to be a problem with one or some of the components.

 

Or, I'll post some pics here and if you see anything oddly different about your's let us know. The breakdown is showing the OEM springs and spacers but other than that........

 

The Progressive instructions are there also for other reference to oil levels.

 

Mike

[jimmyenglish]

Hi guys. thanks for writing. I posted a video. It may or may not play.

 

 

http://www.motopalz.org/86venturefork.3gp

 

 

 

Demonstrates the sliding of the fork tubes. Mike, thanks for the info. Perhaps I should just rip them apart and start over. Sure hope I can get this sorted. This has been a real bummer because the bike is just a nightmare to ride like this.

 

Thanks again guys!

[Snaggletooth]

Vid didn't work for me.

[Prairiehammer]

My suggestion to reinstall the anti-dives was to eliminate a possible cause of the non-compliant suspension. Perhaps the block-off plates are an issue? Inadvertently get a pair for an 83-85 or maybe Earl forgot to mill them to allow bypass? Just sayin' Relatively easy to eliminate the anti-dives as an issue that way.

[reddevilmedic]

i installed mine per instructions. i left the spacers whole. i also have block-offs and stainless de-link. it was VERY stiff for about 1000 miles, then loosened up a little. ps..sometimes fluid is leftover, so they may be getting overfilled

[dingy]

Attached are some Computer Aided Design (CAD) drawings of the forks. These show the hydraulic AD units, Electrics are functionally the same. Couple of the pictures incorrectly show a left hand thread on the lower cap screw.

 

Also attached are a few pictures of the many parts I have cut up to try & understand how these work.

 

The AD can not make any difference until the fork is about 1" from being bottomed out.

 

Replacing them to try to reduce the stiffness will do nothing.

 

There are three different configurations on the bottom tubes inside.83~85, 86~87 & 88 ~93. They vary in the lower lock pocket configuration.

 

Somewhat key with the design is the upper & lower holes to the AD valve ports both open into the lower part of the outer tube & are physically in the same volume of fluid. This does not change until the lower bushing on the bottom of the inner tube passes the upper AD port.

 

I am not sure how the lock valve (shown in green) reacts during the tube travel, so it may not be depicted correctly.

 

Gary

Edited September 22, 2012 by dingy
missed word

[bobcat]

You didn't mention what wt fork oil you put in but under the circumstances I'd try a light weight oil like a 5wt, even a 3 wt..

[Squidley]

When you install progessives not all the original stuff goes back in. Also the level of fork oil is crutial, I have always had good luck with cutting the pvc spacers that go on top at 3/4" and when you fill the tubes with oil (I use 10wt) they need to be right at 5" from the top of the tube with the tubes collapsed and the springs out.

If you could get some pics of how everything came back out that would help a lot....we'll get you squared away

[mbrood]

Progressive and parts (minus desired PVC spacer) -vs- stock and parts respectively (the three inch stock becomes a garage novelty. I used no spacer as the bike leaned WAY over on the side stand and I'm a smaller guy, don't need all of the extra to hold up my 120 pounds (like the bike would know...).

 

http://www.bergall.org/temp/venture/springs3.jpg

[Trader]

I have always had good luck with cutting the pvc spacers that go on top at 3/4" and when you fill the tubes

 

That's the pre-load I was talking about

 

when you fill the tubes with oil (I use 10wt) they need to be right at 5" from the top of the tube with the tubes collapsed and the springs out.

 

I knew it was about that depth of oil...and OF COURSE you have to check with the springs OUT. DUH!

[jimmyenglish]

Hi guys, thanks for all the replies and great info.

 

So, in the video that didn't work, I was demonstrating the easy sliding action of each fork tube sans oil. Satisfied that all was good, I filled with power steering fluid to the 5" below mark and pumped each tube. Now, they are just like before. Compressable, but with all your might. As if the fluid is jammed and is squishing through some blocked oriffice. Still studying the design. Is it supposed to be that stiff? What if I used the hydraulic braking effect, a smaller spring and just cranked the air ride?

 

 

Thanks everyone!

[jimmyenglish]

Hi guys,

 

Here's a working video of what I'm talking about with the forks. This is with no springs, caps off.

 

http://www.motopalz.org/86forks_venture.mp4

 

 

 

Thanks!

[dingy]

Hi guys,

 

Here's a working video of what I'm talking about with the forks. This is with no springs, caps off.

 

http://www.motopalz.org/86forks_venture.mp4

 

 

 

Thanks!

 

Just looked at the video and I really don't know what you are showing. It appears it is taking way to much force to move the lower tube if springs are out & upper caps off. There has to be an assembly issue internally.

 

You said springs are not in forks.

 

Are the top caps in place and tubes filled with oil?

 

How much oil is in tubes if they do have oil?

 

Do lower tubes slide up and down somewhat freely with no oil or upper caps in place? Or is this what you are showing?

 

The only friction point on the tube moving with no oil or upper caps on should be the contact between the fork seal/dust seal with the inner tube. Very minimal friction will be felt due to the upper & lower bushings.

 

Gary

[jimmyenglish]

Yeah Gary, that's exactly what I'm saying. The top caps are off. Springs are out. I fully collapsed the forks and measured 5" from the top. Pumped a couple times.

 

Here's a link to the other video without the oil.

 

http://www.motopalz.org/86venturefork.mp4

 

 

THanks again!!

 

 

 

Just Remembered! Could it be that there were more internals I should've yanked before installing the Progressives? That's why I didn't need the PVC?

 

 

Thanks!

Edited September 23, 2012 by jimmyenglish
important info!!

[KIC]

If I remember... and guys correct me, there are two different washers that go below the c-clip on the forks. One washer had a wider hole in the middle ? Can putting them in incorrectly do anything like this ?

[dingy]

I can't think of a reason that just putting oil in the tubes would cause them to bind up like you showed in video couple of posts back.

 

They appear to be moving normally in latest video with the dry tubes.

 

I can assure you that the block off plates are not involved with this though. I have them on Tweety and a number of others have them, they do not cause the high friction you are showing. The block off plates are no different than a set of MKII electric AD valves that have been unplugged, which is something guys have done to reduce current draw from the AD valves when in traffic.

 

Attached is a picture that was posted of the internal rod assembly. This might be a possibility if the lock valve on the right side of picture is assembled wrong.

 

Gary

[dingy]

If I remember... and guys correct me, there are two different washers that go below the c-clip on the forks. One washer had a wider hole in the middle ? Can putting them in incorrectly do anything like this ?

 

The washer with the smaller I.D. went in first, then the larger I.D. washer went above the fork seal.

 

I can't find picture I had of it, but when I took fork apart at end of season, the upper bushing was being pushed through the large I.D. washer I had mistakenly put in first.

 

I can't see that causing this problem though.

 

Gary

[jimmyenglish]

Well I'm very confused. The only thing I've done in this whole operation is remove the old springs and oil and replace with the new and remove the AD's, replaced with the block offs. I remember hypermileing in the past (pre front end disassembly) and being impressed how much the front end would dive with the ignition off.

 

I've studied these drawings and I just can't understand where are the fluid is going. You can tell by the sound it's getting jammed through some tiny orifice upon compression. Guess a full disassembly is in order.

[OldGazer]

When you install progessives not all the original stuff goes back in. Also the level of fork oil is crutial, I have always had good luck with cutting the pvc spacers that go on top at 3/4" and when you fill the tubes with oil (I use 10wt) they need to be right at 5" from the top of the tube with the tubes collapsed and the springs out.

If you could get some pics of how everything came back out that would help a lot....we'll get you squared away

 

I agree, with one exception: Instead of cutting the PVC spacers, I didn't use them at all. To set the preload I used the original upper piston (the part with the O-Ring). I used 10 wt oil with the level 5" from the top of the fork tube, no springs installed.

[dingy]

I just posted some technical training manuals I came across and one of the topics covered in there is the Anti dive system.

I have attached that section to this post also.

 

This has helped with my understanding of this system and a reassessment of my statement that the block off plates would not cause your problem.

 

As something to try, I would now suggest you reinstall the AD valves and see if that changes your situation.

 

Gary

Edited September 27, 2012 by dingy

[Marcarl]

Reading through this tells me that I would drain the oil and fill it with FORK OIL, no more than 10 wgt. Power steering fluid is much too heavy.

[Pegasus1300]

It sounds like you are getting an hydraulic lock.Thats why it works with no oil but doesn't when you put oil in.It may be just one leg or it may be both legs but you have put something in wrong down on the damper.When you removed the fork leg you should have found the lower damper rod in the bottom of the tube.On removeing it there should have been a rubber piece(oil lock piece and Three(3) special washers,I can't remember if its 2 flat and one wavey or the other way around.If these weren't on the rod they are lying in the bottom of the tube abd you will have to fish them out.If the damper rod is not put back together right you will get an hydraulic lock.