RPM shock installed

[FJmonkey]

I installed my new RPM shock yesterday. It was more work than I had planned on (my fault) so I did not get a test ride in. I wanted to have dog bones so I could put my rear end back where it should be after my upgrade to the GSXR 17 x 5.5 wheel. The 17" wheel with a 55 series sidewall is smaller in diameter. I measured the dog bones of an 89 and figured I would shorten them a few (3 MM) to put things right. I also purchased an 89" swing arm as the 84/87 swing arms will not bolt on using the 89+ shock link. I discovered yesterday that the shock/swing arm mount points might be different than on the 89+ years.

Out with the old, in with the new


Note: Bottom of each swing arm, different attachment configuration to the link arm. No way to bolt on an 89+ shock without updating the swing arm. Moving on...

The ass end all pulled apart:


New to me GIVI cases in the background, to be installed in time for the WCR, possibly Black Hills if my wife kicks me out for being a general PIA.... Why yes, they do make you butt look fat....

And then the feces hit the air recirculation device.....


My Domex (awesome steel http://www.centralsteelservice.com/domex.htm) custom dog bones are nothing close to the proper size.  Off to the store to find some 1.5 x 0.25 bar and fab up something so I can ride today....

My quick and dirty dog bones, cleaner looking ones will be made up soon enough.


The tops got rounded off with a grinding wheel, too much work and fading daylight to clean the bottoms up.

Ride report pending after today, I am off to Mexico very early to visit a friend so I may not post my RPM shock report till after the weekend.

I know, I can be a tease sometime... Kookaloo all....

[aviationfred]

Mark,

Were there any modifications needed to mount the 89' swing arm and relay arm to your 86' frame??


Good time to be doing mods. Imagine this being done the 2nd week of May....

Fred

[FJmonkey]

Mark,

Were there any modifications needed to mount the 89' swing arm and relay arm to your 86' frame??


Good time to be doing mods. Imagine this being done the 2nd week of May....

Fred

The 89 swing arm is a bolt on for the 84/87 year frame, you still need the 89+ shock link and shock.  I had to move the rear brake stay mount over but that was custom on my old swing arm.

[FJ_Hooligan]

That chain looks way too tight!

It looks like there's no droop at all.

[movenon]

Good work Mark !    I know you have been planning this for a while now.  Advise: take some time and ride it for a while before you commit to a final dog bone length. I can't tell you how many of them I made before I found one that was right for me. I started out way to tall.  Small changes in the dimension makes a big difference.

Hard luggage will be nice for trips. Are those the ones that were on Craigslist a few days ago in LA ?  Stay warm (##$%$#@%@$)..... Just about warm enough here today to melt some snow for 30 min....
George

[FJmonkey]

I had a great ride with Simi_Ed and Cap't Ron. Ed had his FJ out for the first time in a long time and the Cap't was simply himself. I do not have a clean ride report on the shock. If you look at my last pic the dog bones are quite low, I went from thinking I needed 3 inch (ish) length to having to making 5 inch (ish) to connect the link arm. That is a huge difference and a RED flag. I got things cleaned up later than I wanted the night before so I did not get in a test ride yesterday. I jumped on and rode it this morning to meet up with Ed and Ron. The first thing that happened was I could not steer properly at low speed, WTF??? Thinking what did I do to break my bike. I returned to my driveway and check air pressure. I always check the air before I take the bike out. My front had about 12PSI,  Check for damage, none, fill up to 40PSI and off I go. Note to self: the moment you bypass a safety check, is the moment you really needed to do it..... 

Then when making one of last turns to Ed's house I heard my center stand scrape, that seems odd.... parked at Ed's and got to looking at my bike on the side stand. My center stand seems way to low, it seems to be pushed down by the dog bones... It was and not safe at all. I removed the center stand at Ed's and left it for the ride. Now I am on high alert that the shock link geometry is likely way out of kilter and may not behave properly. I rode with caution and some back of the mind fear, of what else was going to go wrong.

In short, the new shock seemed stiff but the geometry is not proper. It also performed way better than my sacked out OEM pogo stick. So I cannot offer proper feed back as I still have some issues getting an 89+ shock to fit the 84/87 FJ. I will be in contact with Randy to get his input, I suspect the shock lengths might be different and the shock mount locations also different between the years. This is my experiment to convert my older FJ to have dog bones. I am sure with some problem solving and Randy's help I can get this modification to work. And yes, I will document what needs to be done if others want to make the same conversion. So for me I go down the rabbit hole a little further.

I will let Ed and Ron post up some pics of our adventures, including an "FJ rider down" situation.... 

[Capn Ron]

I had a great ride with Simi_Ed and Cap't Ron. Ed had his FJ out for the first time in a long time and the Cap't was simply himself.

I will let Ed and Ron post up some pics of our adventures, including an "FJ rider down" situation.... 

A brief write-up of our day's events here

http://www.fjowners.com/index.php?topic=12886.0

[Pat Conlon]

Mark, I found that the early '84-87 shocks were longer than the later '89-93.
I initially had my the longer Penske on '84 when I did the TAce conversion and I noticed the relay arm did hang lower (angle~10:30 o'clock) when I went with the shorter '89+ Penske shock and threaded the clevis threads all the way in, the relay arm went up to close to the proper (9:30 o'clock) angle.

I see in the pictures above, you're not going to get any better with a early shock. Perhaps relocate the clevis bolt holes up closer to the shock body?

[FJmonkey]

Mark, I found that the early '84-87 shocks were longer than the later '89-93.
I initially had my the longer Penske on '84 when I did the TAce conversion and I noticed the relay arm did hang lower (angle ~ 7 o'clock) when I went with the shorter '89+ shock, the relay arm went up to close to the proper (8 o'clock) angle.

What is the angle on your relay arm?

I will be away for a few days, I will get a better look at the shock and link when I return.

[Pat Conlon]

Ok, check my edited post. ^^

[racerrad8]

Mark,

We are in uncharted waters converting 86 over to late model swing arm parts.

I have been a doing a little research and we will have to discuss upon you return.

Randy - RPM

[FJmonkey]

Mark,

We are in uncharted waters converting 86 over to late model swing arm parts.

I have been a doing a little research and we will have to discuss upon you return.

Randy - RPM

Yes, I figured that I may be doing some R&D to make this work. I am okay with that, plus once solved, others will have the information to avoid my current issues.

[FJscott]

Mark

when I put the FZ1 shock on my 92 I had similar issues. couldn't use the stock upper shock mount and couldn't use the stock relay arm without losing the centerstand.

I cut off the old shock mount. placed a piece of 1/2 inch plywood under rear tire to get desired ground clearance and made an upper mount out of 2inch mild steel flatbar.

its been a year with no issues. rear end is up where I want it, easy to getr on the centerstand and cornering is improved over stock.

thought id pass it on as a possible option for you. took me a total of maybe 2 hours to do.

[imghttp://fjowners.com/gallery/7/thumb_3302_21_11_14_5_28_53.jpeg][/img]

good luck!
Scott

[FJmonkey]

Scott, was already thinking down that road, possibly due to you posting it. Thanks.

[FJmonkey]

Today I have some time to look at the shock install and compare the OEM set up and the 89" conversion parts I installed. First I put them side by side with a common bolt through the top shock mount.



I noticed that the RPM shock was slightly longer the OEM shock that was in my 86' FJ. The difference only adds to the next detail of why I needed dog bones that were 2 inches longer.



The 84/87 lower shock mounts to a common pivot point, the 89+ to a dedicated pivot point higher than the 84/87 point.



That higher pivot point effectively pushes the shock link further down and the dog bone pivots farther away from the swing arm pivot points.

I suspect that the 89+ frames have a higher upper shock mount location than what I have on my 86' as shown below.



Anyone with a spare frame or access to take a picture of an 89+ upper shock mount, similar to the one above? I need to confirm or deny my suspicions regarding the upper shock mount. 

I will be working with Randy as well on this, as he already mentioned, this is uncharted territory.

Important note:
Randy recommended that I simply use the 84/87 RPM shock. I decided I wanted to have the ability to adjust the rear height with 89+ dog bones. Sometimes Moditus means we create more work to keep us happy/busy with our FJs.