It was a Good Day

[Mike Ramos]

It's a Good Day....

It all began when the rear shock was due for servicing.... 

While it was not a major overhaul, servicing the FJ was time consuming and looking at the FJ in pieces was a rather sad experience – cold and wintery – as it is this time of the year just added to the melancholy feeling...

But a spirited cup of morning coffee and a fun song provided sufficient motivation to get the old FJ off and running again... and so they did and it is...!

First, off came the shock to be sent to RPM.  But then I checked the front end and uh oh (!) the forks also needed rebuilding!  Off came the forks.

Although they could have shipped directly to R.P.M., I thought a visit to the palatial R.P.M. shop would be fun.  The shock & forks were loaded into the car and off they and I went.  Even though an email was sent informing the staff I would be arriving; it was strange to find a sign taped to the door "Midget – leave the parts at the Starbuck's next door"!  Hmmm...

The forks were rebuilt there and the shock was sent for servicing.  Good turnaround time on the shock and the forks as they were waiting when I returned the following week... the sign again referring me to the Starbucks; well, at least I had a good cup of coffee before heading home!

But then the steering head bearings were not as smooth as they should have been – off came the triple clamps. 

Replacement gauges were installed (also on the shelf since the Colorado episode) – off came the windshield, dash and related bits and pieces.

There sitting on the shelf was a set of rear wheel bearings – so, might as well replace those too since the FJ would be down for a while...

Also sitting on the shelf were additional tail/running lights so I took the time to install & wire those into the system.

Somewhere along the way, the crankcase vent tube had hardened and split – naturally on the low end where it exits the crankcase and the area behind the barrels under the carbert, the carbata, the cartbud... well, under the carbs had collected a bit of oil.  So, off came the carbs and the shrouds, although the wires themselves were still in good shape, the cover over the wires running across from the left to the right side wiring harness had hardened.  So, a new wiring covering was installed and the area cleaned and a new vent hose installed.

So after a few weeks of servicing it was a delightful ride from morning to night... and all night too...

Ride safe,

Midget

https://youtu.be/3wnQLchU754

[ZOA NOM]

Toe-tappin delight, Mike!

[Pat Conlon]

Thanks Mike!  How many miles on your shock before the servicing?

Did a Starbucks really open next to Randy's shop? Hard to believe...
It will be a cold day in hell before the Raduechel family sets foot in a liberal Starbucks...

Cheers

[ribbert]

Having the RPM shocker serviced from Australia is impractical but I have always wondered just what it is they "service" on them.

Noel

[ZOA NOM]

Thanks Mike!  How many miles on your shock before the servicing?

Did a Starbucks really open next to Randy's shop? Hard to believe...
It will be a cold day in hell before the Raduechel family sets foot in a liberal Starbucks...

Cheers

Look at you, pokin' the bear...  

[ZOA NOM]

Having the RPM shocker serviced from Australia is impractical but I have always wondered just what it is they "service" on them.

Noel

You gotta replace the Fallopian tubes once a month, along with the power band. 

[ribbert]

Having the RPM shocker serviced from Australia is impractical but I have always wondered just what it is they "service" on them.

Noel

You gotta replace the Fallopian tubes once a month, along with the power band. 

Thanks Rick, I'll order the parts tomorrow.

Noel

[TexasDave]

Having the RPM shocker serviced from Australia is impractical but I have always wondered just what it is they "service" on them.

Noel

You gotta replace the Fallopian tubes once a month, along with the power band. 

Thanks Rick, I'll order the parts tomorrow.

Noel

Fallopian tubes? Noel I think you are a little old for a sex change operation.   

[Pat Conlon]

I'll post a "parts wanted" ad right away....ok to use Noel's email addy?

[ribbert]

Fallopian tubes? Noel I think you are a little old for a sex change operation.   

I thought it was mandatory if you owned a "pink striper"

[rlucas]

I'll post a "parts wanted" ad right away....ok to use Noel's email addy?

New, used, OEM, or New Old Stock?

[ZOA NOM]

I think we've officially jumped the shark... and I admit I started it..

[racerrad8]

Having the RPM shocker serviced from Australia is impractical but I have always wondered just what it is they "service" on them.

Noel

There are several things within the shock that are wear items. We went just over 42K on Mike's shock one time and it had worn completely through the shaft bushing, damaged the seal lost the majority of the oil. This might have also led to the latest issue we had with mike's shock, but it took a couple of more rebuilds to show up.

Unlike a traditional shock which have no "moving parts", the inside the RPM Shock has many. What I mean by "moving parts" is the shim stack and IAT bypass valve. The other component that the RPM shock does is it creates a high pressure within the shock as it works. Traditional shocks have a variant of pressure ranges depending on the size of the orifice and the viscosity of the oil used.

The conventional shocks are all control with fixed or adjustable orifices that restrict oil flow and dampen the spring oscillation. This is why the shock was developed in the first place back in the 1800's; to remove the bounce from horse drawn carriages and early automobiles. Noel, I know you know about friction shocks just like I do, which was some sort of cow hide and the later an asbestos disk with spring loaded friction between two arms. The goal; remove the spring oscillation and stop the passengers from being bounced out of the carriage.

Well, technology has changed so much since then; the shock is now a part of the total suspension package. Since the shim stack can be used to control the spring rate, it now has to be an advanced part that requires maintenance.

Mike "The midget" Ramos has actually be a continued testing model for the RPM shock as he has more miles on his shock than any other and we are continually learning from his shock, if we haven't gone over 200k yet, it is really close. The reason for this is the manufacture is very big in the off-road world for motorcycles, buggies and trucks. But in the off-road world, they run a 1000 mile off-road race and they rebuild the shock(s). The Harley and dual sport market just do not accumulate the miles that Mike does on his FJ.

So, in the third rebuild phase of the shock the manufacture asked to see just how far we could go before experiencing issues. We had rebuilt the shock at 25K the first two times and there was no significant wear present. So, we bumped it up to 50k for the 3rd rebuild. Well, at just over 42K Mike saw a drop of oil on the garage floor. He rode it a little more and almost immediately noticed the shock performance had gone away. So, off it went for a rebuild.

Inside it was found to have worn the shaft bushing and caused the shaft seal to fail. Once the shock lost some of the oil, and the shaft was damaged. Everything else looked very good inside. So, it got a new shaft, a resigned on the bushing for longer wear, a new seal and oil. They then recommended the rebuild time frame to be in the 30-35K range because the remaining oil was toast in the in the 42k shock. Since the shock only holds about 1/3 of a liter, there is not much oil there and it just gets used up.

So, we have been rebuilding Mikes shock at 30-35K since then. We have done that twice and no appreciable wear was noted. So each rebuild was the disassembly, inspection, replacement of the shaft bushing and seal with new oil. We are able three rebuilds into that cycle.

So, we are approaching 200k miles on the shock and approaching the rebuild time frame in about 10k more miles. Mike started to notice the rear of the FJ was starting to "float". It was difficult to explain, the bumps were being absorbed just fine but the rear of the bike was floating/wallowing and not properly planted like it always has been.

So, we pulled the shock a little earlier than the 30-35K range and sent to down for inspection & rebuilding. The shock was again rebuilt and they did not even replace the shaft bushing this time because there was no evidence wear. They replace the seal & new oil. The only thing they found abnormal inside was the spring for the IAT circuit had come unseated. So it was replaced and away we went. We put the shock back on Mike's bike and it was not any better, it was still floating at the "high highway speed" or "slow speed movement" of the shock. It still soaked up the high speed (large bump/pot holes) without issue.

So, off it went back to the manufacture. During this time, since I wasn't riding my shock went on Mike's bike to ensure it wasn't something with the bike. Mike's FJ again is performing flawlessly. Mike is now a little frustrated with the shock as there is something wrong with it since mine works fine.

Jon, the manufacture drives up from SoCal to my shop on a Friday to rebuild the shock in front of me so maybe a different set of eyes can see something. During disassembly I am asking all sorts of questions because I have never see the inside of one in person. As he takes it apart I question a small amount of oil on the nitrogen charge side of the compression cup, but he says that is normal as you cannot get it all out during the assembly. It comes apart, everything is inspected but nothing major is found. Jon decides to take the shock home because as we are discussing, I am question thing the wear of the tube and the possibility the high pressure oil can be bypassing the piston seal (the oil on the top of the compression cup). We use my bore gauge and find less than .001" of wear in the body, but now he is not sure either. This is new territory for them; they have never seen a shock with this many miles.

So, he reassembles it here at the shop as I watch so I can see how it is done. He drives back home that same day leaving here about 3pm and gets home between 11 & 12pm. I get an email from him at about 1:30 Saturday morning with the dyno charts from Mike's shock and the new one from the shelf. There is definitely an issue as the two graphs are significantly different with Mike's shock never really staying steady and the bypass appears to never stop working. So, we start talking about things and what is could be. He feels the shock body is not the issue, but wants to replace it and see if that makes any change. He wants to work on making single changes to make sure we know what the problem is.

Monday, I get and email with a similar dyno chart of Mike's shock with a new tube. Jon is a little perplexed and not sure what is going on. As we discuss I noted during the rebuild the IAT valve was a complete unit and he cleaned it, checked for free movement, the spring was properly seated and put back in the shock. It was never completely disassembled for inspection. Since the dyno sheet is not changing maybe the IAT valve is worn someplace they have never seen. So, he puts a complete new IAT valve in the shock and bingo, the dyno sheet matches the new one from the shelf.

So, Jon breaks down the IAT valves, something he has never done since they started the business as the valves have never been an issue, it is always bushings and replacement of the bushings, seals shims & oil. A few tubes & shafts due to damage, but never from wear.

Inside the IAT bypass valve he finds the piston internal bore & shaft the piston rides on has worn through the hard anodized coating. Since the IAT piston & shaft are shrouded it cannot be seen with complete disassembly. So, the IAT valve was allowing oil to bypass the circuit and the shock was floating on the back side of the shim stack, which was Mike's observation all along.

Up until this point during their years of building shocks they had never seen this type of wear in the early years, so they had never gone back and looked since then. But since Mike's shock has so many miles, it is showing wear in places never seen before. As we looked back on it, we wondered did the wear start a few rebuilds ago when the oil leaked out of the shock. So, they will be inspecting IAT valves regularly on any shock that has over 100k miles or if one comes back low on oil to see when the wear begins.

One thing I did learn out of all of this, which seems obvious but it really isn't because it seems backwards...

We did note the wear in the tube in the "middle" of the stroke range. Jon found this to be strange as well, but as we talked about we think we have figured it out since he has never seen wear like this in his off road shocks. There is more internal wear of the shock traveling down the freeway and sport riding because the shock only travels limited range. When you hit a pothole or large bump, the shock has full stroke. So, in Mike's shock the wear noted in the shock tune was in the middle of the stroke which signifies low range of shock travel as compared to the off road shocks they build. By looking at the street shock and the off road shock you would think it would wear out faster due to the extreme use. But Jon notes this is just the opposite. The street shock with it normal limited travel creates more wear short stroke range of the tube, where the off road shock that uses all of the tube. Jon said the irony of both shocks is the shaft bushing wear is about equal between both shocks.

So, to round this out, there are many things that need to be service in the RPM shock. If those are not serviced, problems will crop up.

I would like to thank Mike for his patience, commitment and dedication to the continued development of the RPM shock and RPM fork valves. Without Mike's dedication to what I do, we would not know many of these issues. There is no one else that I know that puts such a high amount of miles on his FJ. Mike also has a skill & ability to give excellent feedback on the RPM suspension components and will do whatever I ask him to do for the continued development and improvement of the RPM product line.

This last shock deal drug out for several months between rebuild, shipping back & forth and riding, but it was Mike's initial observation that lead to the discovery of the issue. Now we are better prepared for the future.

Now, as far as Rick's recommended part lists, I think he tried to save a little money on the new bike with the stock shock and replace those parts...But that was to no avail, as the RPM shock is now firmly in place of the O.E. shock on that new FJ.

And Pat, I'm surprised...I was in a Starbucks last Thursday. The three guys behind the counter all had man buns and the only girl working in the place had a nose & cheek studs and gauges in her ears...I only stopped there to use the restroom since I don't drink coffee...

Randy - RPM

[ZOA NOM]

Wow, sounds way easier to do what I said...

[ribbert]

Thanks Randy, that is a great run down on the post production history of the shocker and explains the need for service well.

Noel