The new RPM fork valves are scheduled to be in stock next week. I have also ordered the oil and several sets of springs to get started.
When I started looking into the production of a fork valve for the FJ, the bench mark was the R-T gold emulator. When I spoke with the manufacture they assured me that their fork valve that could be made for the FJ would make the R-T valve comparable to the old friction shock on cars.
Well, not being much of a suspension guy, regarding M/C forks anyway, I proceeded with the manufacturing and testing of the valves. As it has been well documented there was an issue that delayed the testing for many, many months. That required me to purchase more valves to offer to FJ owners that were willing to do testing of the product. With the help of the members from this group, I was able to get the original fork valves I sent off back and get them out for testing as well.
So, there were four sets out for testing and the feedback I got was great. We were able to work through spring rate issues and get them dialed in for the best performing valve yet.
Now, as I said earlier I was not a M/C suspension guy but once I got the springs dialed in on my bike the ride was incredible. The spring rates were then altered to those who did the remainder of the testing and the charts were calculated. I still needed to obtain a set of the R-T valves so that I had some idea of the differences between their valve and the new RPM valves.
So, the R-T valves came in and I can see the difference just be holding them in my hand. Right away I can tell these are not "true" valves as they have two holes drilled in them that allow oil to pass only being regulated by the diameter of the hole(s). They do have a spring that will allow the valves to bypass when suddenly shocked, but these do not control the oil effectively.
Not only that they require the dampening rod to be removed and modified by drilling the existing holes and adding more. Heck the instructions are four pages long.
The RPM fork valves require 9 steps and no drilling or modifications are required with the exclusion of cutting off the dampening adjuster rod.
The RPM fork valve is a true shim pack valve that can be tuned by changing shims if required that control oil flow just like the performance shock found on cars today. Since these fork valves are actually creating "pressure" in the upper & lower chamber the spring rate can be lower than normally used with the R-T valve. The stiffer spring rate helped the R-T valve control the oil by mechanical resistance.
The only similarity between the RPM fork valve and a R-T cartridge emulator is where it fits in the fork. The emulator improves it by giving a blow off style damping response. Low speed resistance is increased to reduce brake dive and the high speed impacts are lessened to prevent hydraulic spiking. With conventional shock systems, there's always a compromise between stability and comfort.
The RPM fork valves uses a patented inertia system. The inertia valve is designed to 'read' the road surface and move between the stability circuit and the comfort circuit within milliseconds, seamlessly. Because the inertia valve can sense any bump and cause the shock to go soft instantly, the stability circuit is valved a few times stiffer than a conventional shock could get away with without being too harsh. The inertia valve does not open for frame inputs regardless of the psi. The inertia valve is very sensitive to the wheel inputs only. The RPM fork valve equipped front fork can follow rough surfaces much better and traction is improved.
The bottom line is brake dive can be reduced along with better comfort, stability and traction compared to convention force/velocity shocks. The damper rod fork structure works well with the RPM fork valve insert because the piston surface area is much larger than cartridge forks.
I do not have the final price established at this point as I have to calculate the shipping charges from the factory to me.
The valves will not be able to be used with stocks springs as they are too soft and allow the RPM fork valve to lift from the seat and bypass. But with that said the springs are going to be softer than would be required for the R-T valves. I will have a chart posted with the valve listing the spring rates based on rider(s) and gear weight.
One thing that came to light right away with the improved front fork valving was the poor rear shock valving. I inquired about the process of making a rear shock and sent them both versions of the rear shock. Both versions of the shock is in initial production now and after talking with them this morning, I should have the rear shock in my hands for testing in 2-3 week. I am getting one of each version of the shock and they will be install on the bikes that are already testing the front valve because all they do is complain about how the back of their bikes are "slapping their behinds".
I need to work through spring and valving rates at the start of the rear shock testing. The standard rates for the rear spring are also going to be lighter than the standard aftermarket coil-over design based on the internal valving design. I will have the rear shock on my bike for the double WCR then Colorado rallies, the late model shock will definitely at the Colorado rally.
I hope the initial testing will allow a couple of more to be made and put out there for testing to expedite the process.
I look forward to the next couple of weeks when the fork valve head out for you guys to start using and then to follow it up with the rear shock that hopefully makes the other aftermarket coil-over shock feel like old friction shocks as well.
My goal when I started this was to make the RPM fork valves and now the shock was to be the new standard of excellence for the FJ suspension, and the results I have in my pocket right now leads me to believe I will succeed.
I will post up when the RPM fork valves are ready to ship.
I again thank each and everyone of you for your continued support.
Randy - RPM
watching with interest..........
:)
I would be really interested in seeing how these compare to Race Tech valve emulators.
Quote from: ally on March 09, 2012, 03:45:57 PM
watching with interest..........
:)
Same here. :biggrin:
I can say with first hand knowledge, the difference between the FJ damper rod forks with R/T emulators, and a true cartridge fork with properly set adjustable (tunable) shim stack is night and day. A Big improvement. Huge.
8 years ago, Jon Cain installed (via a special hat) some R/T Honda CBR600 F3 cartridges on both my FJ's. A very cool upgrade.
For over 8 years prior to that, I had used the R/T cartridge emulators and 1kg/mm straight rate fork springs.
For sure, the cartridge emulators were much better than the stock damper rod set up, no doubt, but the difference between the R/T emulators and properly set up, true cartridge forks was amazing. It is exactly as Randy describes.
Rather than trying to find scarce Honda F3 stanchion tubes, buying the $$ Race Tech cartridges, and machining a special hat for the cartridges to fit in the FJ lower sliders, Randy's solution is plug and play.
The key words here are "properly set up". Unlike the scarce Yamaha YZF750 cartridge forks with external screws for compression and rebound adjustment, with Randy's cartridges, the compression and rebound are set by using the proper number of shims in the shim stack. Meaning: you have to take apart the forks to change the shim stacks if you need to further tune the forks. Yes, it's a PIA.
It appears Randy has taken all the guess work out of setting up these cartridges.
Kinda like the Ronco oven: You set it and forget it. Kudos Randy.
You folks will be amazed in the night and day difference a properly set up cartridge fork will make on your FJ. I sure was.
Jon Cain said it best,
"It's kinda cool to go down the freeway and hear your bike roll over the expansion joints, and not feel them thru the bars..."
Quote from: Pat Conlon on March 09, 2012, 07:34:55 PM
...Meaning: you have to take apart the forks to change the shim stacks if you need to further tune the forks. Yes, it's a PIA.
It appears Randy has taken all the guess work out of setting up these cartridges.
"It's kinda cool to go down the freeway and hear your bike roll over the expansion joints, and not feel them thru the bars..."
Pat, the best part if someone does have to "tune" the RPM valve, all they have to do is reach down with a part grabber tool and retrieve the valve after the top & spring have been removed.
I have done it many, many times and I can have both valves out of my bike and on the bench in less than 10 minutes. No other dis-assembly required.
That is the first thing I had each of the test riders do..."go out into the roadway and run over the raised reflectors and when you get back, tell me what you feel".
Each one of them said the same thing, I can feel it in the bike but it is not transferring into the bars...That is why the back end of the bike is now bouncing against every ones backside...Heck, one of the test riders tells me he rides around looking for potholes and rough patches because he still cannot believe the ride.
Thanks for the supporting words Pat, I forgot you were one of the first people to see them before I got started testing. I think that just by holding them, you could tell they were going to be an improvement over what is on the market now, even before I knew what I had in my hands.
Thanks again, Randy - RPM
If this is going to be ready next week I'm game, as I am about to pull the trigger on springs/emulators/bushings/seals from Traxxion by next Friday. I'd rather give you the money, at least for the fork; I intend to have a penske on the back by the first week in April so something tells me your shock won't be ready by then.
Quote from: racerrad8 on March 09, 2012, 08:24:19 PM
Pat, the best part if someone does have to "tune" the RPM valve, all they have to do is reach down with a part grabber tool and retrieve the valve after the top & spring have been removed.
I have done it many, many times and I can have both valves out of my bike and on the bench in less than 10 minutes. No other dis-assembly required.
That ^^ is gonna be much easier than r/r the Honda F3 cartridges. Instead of figuring out how many shims a CBR600 F3 cartridge needs to support the FJ (a bike weighing in at over 130 lbs more than the 600 Honda) you have done all the hard work. Cool.
Randy, find out if the mfgr. will make them as replacement cartridges for the 1992 Yamaha FZR1000 USD forks (I have on my '84) TIA. Pat
Re: RPM's fork valves: Well now, I am pleased to see that the long awaited Fork Valves will soon be available.
I was at Randy's shop for a valve adjustment a few months ago and of the several subjects we discussed, suspension was at the forefront; principally because of a set of prototype fork valves that Randy had received. My opinion was that based on my limited riding abilities, the stock setup was more than adequate (if you want to see a stock suspension working overtime, there is a posting on this site titled "California Cruise"). Randy's comment was that limited riding abilities or not, the improvement would be noticeable. He then offered me the one set that he had to test.
Initially I declined his generous offer. However, from a safety standpoint, I do feel that any improvement(s) that increase the safety margin within which we find ourselves should be considered (wider rims, modern tires, improved brakes, brighter lighting front & rear etc: all of which I have incorporated); I also believe in full leathers as well. Thus from the aspect of an improvement in safety, on a return visit I did indeed accept his offer... and in my case the rest is history.
My first ride with the valves installed was a late night run from Oakdale to the Bay Area, a distance of about 90 miles. This ride encompasses the back (eastern) side of Altamont Pass, sections of which are choppy and shallow but sharp edged pot holes over which I passed with unbelievable ease. It was very windy and my speed was well into the 80's. I have travelled this section before several times and the difference was truly night and day. The fork absorbs the impact yet the impact is not transmitted to the bars & grips.
I do a lot of riding over many types of road. Independently & without Randy's knowledge, I adjusted the fork preload over different types of roads. I also removed the fork caps and shimmed the springs, in effect giving me an adjustment of 1/2 notch in the spring preload. I have settled on the #2 setting which gives me an exceptional all around ride under almost any road condition. Any improvement over Randy's initial seeings was marginal if at all.
Bear in mind that I carry 11 gallons of fuel, thus there is approximately a 70 pound difference between full tanks and reserve by the time I stop for fuel. The fork valves compensate for this change in weight as the stock forks never could.
From an installation standpoint I do not understand the PIA point of view. The fork caps and the springs are removed, the valves inserted and then the spring and caps are replaced. Simple and straight forward.
Late one night traveling to the Bay Area from far Northern California, the Hwy. 505 ends and enters Hwy. 80 in a right hand sweeper and then roadway is in poor shape. Having traveled this road I knew what to expect and there is a wide run off area. It was a short but sweet first chance to test the forks at high speed. Well into the 90 mph range, the fork suspension was remarkable. Granted the lean angle was modest, but since then I have had opportunities to dabble in many different speeds and road conditions. To date, I have well in excess of 1,500 miles logged. The only limiting factor is poor weather in the foothills and mountains of far Northern California.
Unknown to me, Randy appears to have others test the units as well. Apparently all his feed back has been positive...
And yes, based on my personal experience with the fork valves, taking into account my riding style and limited ability, incorporating the safety parameters within which I ride the fork valves are a substantial improvement.
Thus without reservation, I now have the confidence to purchase a rear shock as soon as they become available.
It is a substantial but prudent investment; the suspension improvements are at least on par with and conceivably better than any other modification that I have made.
Ride carefully,
Mike Ramos.
Quote from: Mike Ramos on March 10, 2012, 01:15:33 AM
Unknown to me, Randy appears to have others test the units as well. Apparently all his feed back has been positive...
Ah a blind study, starting to smell like the scientific method. So the question becomes, who got the placebo?
Actually, this would really be interesting;
1 group gets nothing except an external fork clean (control / placebo)
1 group gets fresh clean oil and new springs
1 group gets the R-T gold emulators
1 group gets the new fork valves
with an n = 200 would do it. You would have to be careful to try and control for variables (there are about a million)
The feedback data collection could be a 20 question survey....
...or...
you could just see if a few known good riders like 'em. :)
Dan
Randy, will the new fork valves affect the oil level in the tube, that is, will I have to remove some of the fork oil?
Thanks,
Chris
You've mentioned that the new valves are working best with a moderately lighter springrate, and I have questions about that.
Is it altering the static sag somehow, with the new units? (Shouldn't, obviously!)
Or is it just more that you're easily able to control the movement of the lower assembly, and don't need a huge amount of spring rate to try and prevent bottoming?
If it's working the way I'm thinking it is, I'd like to see what would happen in a later model (>88) that has some preload spacers added to the stock fork springs, as that would still leave them a bit soft, but would kick the sag down a pinch, riding higher in the total travel. Just a thought!
I'll very probably be looking at a set of these sometime, so just getting some groundwork research done first :)
To keep Randy's topic on his fork valves, I've split out the discussion on Mike's 11 gallon fuel capacity into a separate post.
http://www.fjowners.com/index.php?topic=6122.0 (http://www.fjowners.com/index.php?topic=6122.0)
ok I'm convinced , these fork valves sound like a must have , but how much will they cost $$ ?? if money was no object for an excellent product I would order them now :good:o
Quote from: grannyknot on March 10, 2012, 08:27:02 AM
Randy, will the new fork valves affect the oil level in the tube, that is, will I have to remove some of the fork oil?
Thanks,
Chris
Chris,
The oil level will still be the same setting/level after the valves are installed. It will take slightly less oil that the stock setting due to the thickness of the valve itself.
With that said the valve is designed using Motul Factory Line 5w 100% Synthetic Ester fork oil. The valve was designed around the Motul HVI ratings and standard fork oil will not live due the increased in internal pressure the valves are generating.
You are going to drain and refill the fork with the specific oil and then fill it to the appropriate level. the fork will need to be cycled to remove the trapped air. The RPM fork valve will be install end pushed to the seat. The fork needs to be compressed and the level will need to be adjusted from the top down.
Randy - RPM
Quote from: fj11.5 on March 10, 2012, 03:56:15 PM
ok I'm convinced , these fork valves sound like a must have , but how much will they cost $$ ?? if money was no object for an excellent product I would order them now :good:o
I will have the final price once I get them in my hands. I am awaiting the shipping total from the manufacture to me so I can figure that into the cost of the part.
Hope to have them and the final price up by Tuesday.
Randy - RPM
Quote from: andyb on March 10, 2012, 08:43:47 AM
You've mentioned that the new valves are working best with a moderately lighter spring rate, and I have questions about that.
Is it altering the static sag somehow, with the new units? (Shouldn't, obviously!)
Or is it just more that you're easily able to control the movement of the lower assembly, and don't need a huge amount of spring rate to try and prevent bottoming?
If it's working the way I'm thinking it is, I'd like to see what would happen in a later model (>88) that has some preload spacers added to the stock fork springs, as that would still leave them a bit soft, but would kick the sag down a pinch, riding higher in the total travel. Just a thought!
I'll very probably be looking at a set of these sometime, so just getting some groundwork research done first :)
Well, let me try and write this so it makes sense...
The stock configuration and the R-T emulator are functioning off of a controlled orifice to modulate oil flow and control the dampening of the fork(s).
Compression:If you look at the R-T valve there are two 1/8" holes (1/4" total) in the upper seat of the valve. Those holes allow constant movement of oil with the only regulation being the combined size of the holes and the viscosity of the oil. If the wheel is jarred and the oil cannot pass through the holes fast enough the viscosity of the oil will unseat the valve by compressing the coil spring and allow it to bypass. Once the valve re-seats the oil then is again control through the two holes.
The RPM valve is an actual shim stack that the oil must force it's way through in order to get to the other side. There is no "hole" that is sized to control oil flow, it is an infinite regulation. The shim stack distorts allowing the oil past them and this is where the RPM valve shines. I have spent close to 10,000 miles last year riding my bike, with a wide array of shim stack profiles, fork oil viscosity & levels and spring rates to get them valve to be the best drop in valve for the "standard" FJ rider.
The other component of the RPM valve is the "Inertia Active Technology" (IAT). This portion of the valve works in conjunction with the shim stack. Without this portion and design the oil would have to force its way past the spring stack all of the time which would result in a harsh/stiff ride. The IAT is a valve that regulates oil flow, not just a bypass/dump valve like used on the R-T. The valve opening is controlled by the jarring force of the wheel movement and the spring tension set on the valve.
Now, the real benefit of the RPM valve is the valves ability to differentiate between high speed and low speed compression travel. I know it sounds backwards, but the relation of road speed/MPH and shock function are 180.
High speed travel is the sudden movement of the wheel when a pothole, bump or other jarring movement actuates the fork. This high speed movement initiates the IAT valve which as the wheel speed slows the shim stack begins working.
Low speed travel is the travel most associated with cornering. This is the slow speed compression of the forks during cornering. During this slow speed travel the IAT does not come into effect and the oil must pass through the shim stack which is the controlling motion of the shock and provides stability when cornering.
Now, with that said if you to strike a pothole mid-corner and the high speed movement is enough to initiate the IAT valve, the stability is not lost as is quickly absorbs the high speed travel and then goes right back the shim stack. Again, the IAT valve is not just a bypass/dump valve but a regulated valve that determines the amount it needs to open based on the high speed input movement.
The increased stability when cornering is incredible and I had not fully realized it until I rode a customers bike from San Fransisco last weekend. After all of those miles on my bike and I can tell you his bike spooked me a few times on the rough Nor-Cal freeways.
Rebound:The rebound portion of the valves are very similar in both valves with a light rate shim stack that opens to allow the oil to pass quickly to the bottom section of the fork allowing weight transfer for acceleration.
SAGNow, back to static sag; the difference in the sag in nominal, but when doing the static sag measure it take a little longer for the fork oil to pass through the shim stack. Before, you could just get on the bike and take a measurement. Now, you need to sit on the bike, in the riding position and take the 5, 10, 20 or more seconds it take for the bike to settle on the front forks. This is where the helper holding you up on the bike in riding position was helpful. I can say the ambient temperature has a direct effect on the time it takes for the oil to pass. But with the light weight synthetic oil, the time required is not much, but it is not instantaneous like with the stock or R-T systems.
Another thing is that the RPM valve is about half of the thickness of the R-T valve so that is going to drop the sag by the difference.
Springs:The last thing that makes the RPM valve different from the R-T valve is based on the fact there is no "holes" that allow oil to flow between the upper & lower chamber. The oil within the fork is now pressurized as it must pass through a shim stack for each direction of travel. This internal pressurization removes the requirement of the spring to hold up all of the weight and this the reason for the lighter spring rates. Without this internal pressure then the spring rates required to hold up the bike would be similar to those on the R-T and stock systems.
I tried and tried to make the valves work with stock springs, but there is just no way the stock .65 progressive rate spring will work. The weight of the FJ requires the shim stack to be much heavier than the other valves the company produces. Once the shim stack increased I started having issues with the stock spring allowing the valve to raise off of the seat which resulted in an instant oil bypass. The produced some really scaring initial testing. We tried heavier oil with lighter shim packs, lighter and heavier IAT springs; every conceivable configuration was tested trying to allow the use of the stock spring but there was no way.
The lightest spring that prevented lifting was the .80 with my son who is about #165. So, the .80 is the spring when the rider/cargo is under #170, from there it goes up gradually to a 1.0 for #325+ rider/cargo weight. I will have a chart on my website documenting the the spring rate based on recommended weights.
In closing, like I stated in my original post, I was not a educated in M/C fork suspension, but have a good knowledge of race car shocks and the tuning with the shim stacks. I have since been educated on the M/C version of the shock, the front fork which is really just a really big shock absorber with an internal spring. The patented IAT valving was really cool to work with and I have learned a lot about the tuning and setting of the FJ front suspension.
There will be some people who might need to take the RPM fork valve to the next level if they are track riding a lot and can benefit from the tuning portion of the valve based on track conditions and race tires, but the current configuration of the valve has a little over 20,000 miles of testing by myself and three other riders from the US and abroad. This final combination has now been put into all of the bikes and the results are impressive and all test riders are happy. I have had the testers on both sides of the current settings and they all agree this configuration is the one that best suits the riding the majority of the FJ enthusiast rides, public road twisties & freeway. The RPM fork valve is a benefit in all forms of the FJ riding experience.
The best part is the rear shock is going to have the same technology as the front fork valves and I expect the results of that to trump the current aftermarket options for the FJ.
I will continue to search for, manufacture and supply items that will make your FJ ride better, run better and hopefully last forever.
Randy - RPM
Very cool, thanks for keeping the FJ current and safer to Kookalooo!@!@!
I need a set for my 89' forks, along with some new case seals. Order is on the way.
Randy,
Your description of these Fork Valves makes them sound nigh on the perfect answer for FJ forks.
Question: If you've already modified the damping rod for R-T emulators, do the holes need to be closed?
Cheers,
Arnie
Quote from: Arnie on March 11, 2012, 07:56:47 PM
Randy,
Your description of these Fork Valves makes them sound nigh on the perfect answer for FJ forks.
Question: If you've already modified the damping rod for R-T emulators, do the holes need to be closed?
Cheers,
Arnie
I asked that specific question and they said, "No, the valve is now the control and the flow oil oil in other parts of the fork are no longer relevant".
They did stress that the lighter spring will offer the best performance compared the the stiffer spring requires for the R-T valve.
Randy - RPM
Quote from: racerrad8 on March 10, 2012, 05:11:23 PM
Quote from: fj11.5 on March 10, 2012, 03:56:15 PM
ok I'm convinced , these fork valves sound like a must have , but how much will they cost $$ ?? if money was no object for an excellent product I would order them now :good:o
I will have the final price once I get them in my hands. I am awaiting the shipping total from the manufacture to me so I can figure that into the cost of the part.
Hope to have them and the final price up by Tuesday.
Randy - RPM
I think everyone is with me waiting with baited breath. (popcorn)
Quote from: skymasteres on March 13, 2012, 10:36:24 PM
I think everyone is with me waiting with baited breath. (popcorn)
Yep, me too...
I talked them this afternoon after they did not arrive today and was told there was a supply problem with a component of the valve, which is now resolved and the production was continuing. They
hoped to have them done tomorrow and headed my way...
They told me they thought they were prepared to complete the order, but due to the quantity I ordered, they were short some parts.
I guess I spoke just a little to soon...
Believe me once they are here they will be post and I will advise they are here.
Sorry for the delay, Randy - RPM
Quote from: racerrad8 on March 13, 2012, 10:51:23 PM
Yep, me too...
I talked them this afternoon after they did not arrive today and was told there was a supply problem with a component of the valve, which is now resolved and the production was continuing. They hoped to have them done tomorrow and headed my way...
They told me they thought they were prepared to complete the order, but due to the quantity I ordered, they were short some parts.
I guess I spoke just a little to soon...
Believe me once they are here they will be post and I will advise they are here.
Sorry for the delay, Randy - RPM
And then...Depression set in.... :cray:
Love that movie!
"You can't leave! All the plants will die!"
DavidR.
Quote from: SlowOldGuy on March 15, 2012, 02:35:53 PM
Love that movie!
"You can't leave! All the plants will die!"
DavidR.
Ishtar?
Quote from: SlowOldGuy on March 15, 2012, 02:35:53 PM
Love that movie!
"You can't leave! All the plants will die!"
DavidR.
"Sargent, does this mean we're done for the day?"
"Lighten up Francis"
DavidR.
Quote from: SlowOldGuy on March 15, 2012, 07:05:09 PM
"Lighten up Francis"
DavidR.
Oh yeah... "Son of Beeetch. Sheeet".
"where the fucks-my-truck?"
and
"chicks dig me because i rarely wear underwear and when i do it's usually something unusual"
and
"have that fixed"
and
"that's because you've never had the aunt Jemima treatment"
Cutting to the chase:
http://www.imdb.com/title/tt0083131/quotes (http://www.imdb.com/title/tt0083131/quotes)
Dan
"The rumors of my death have been greatly exaggerated"
The RPM fork valves are on the way, tracking number received and I will have them on Monday.
Randy - RPM
Hey Randy,
Do you have a kit that has all of the bushings needed for the rear swingarm? After I get this fork sorted out this week I'm ordering a penske shock. I figure in the 55K miles I've ridden my '84 it hasn't been touched (and I'm sure the original owner I got it from never did either) so when I put the shock on it would be a good idea to go over everything. I know the FJ UK guys sell all of this, but frankly after the hosing I took on shipping and import fees when I ordered my Bagster tankbag and tank cover from them I'd rather not mess with buying from there ever again. Never mind the 17 pound member's fee on top of it.
Thanks!
Quote from: E Double on March 18, 2012, 09:39:38 PM
Hey Randy,
Do you have a kit that has all of the bushings needed for the rear swingarm? After I get this fork sorted out this week I'm ordering a penske shock. I figure in the 55K miles I've ridden my '84 it hasn't been touched (and I'm sure the original owner I got it from never did either) so when I put the shock on it would be a good idea to go over everything. I know the FJ UK guys sell all of this, but frankly after the hosing I took on shipping and import fees when I ordered my Bagster tankbag and tank cover from them I'd rather not mess with buying from there ever again. Never mind the 17 pound member's fee on top of it.
Thanks!
At this point I do not have, and I do not of anybody makes a "kit" for the swing arm bushings/bearings. I have started to compile some bearing numbers but I have not been able to get very far yet. I would imagine that there are bushings out there that fit other bikes that are the same as the FJ, but I have not had the time or opportunity to do a lot of research.
Once I get the RPM fork valves online, I will spend some time and try and get some of that figured out.
You might want to hold off on the shock for just a bit, I know it is going to be a little bit of time for the rear shock to get testing done, but if the rear shock works like the fork valves, this is going to make the Penske shock look like the R-T valves.
The Penske shock is a shim pack shock, but there it does not have the patented inertia valve that the RPM shock will have. The Penske is a compromise of valving to give a "comfortable" ride while still providing a control shock dampening. RPM shock will be able to be tuned for the best dampening and the inertia valve will give great ride.
When I got the tracking number on Friday I confirmed the rear shock in being made as well and he said I will have both prototypes in 2-3 weeks. I want to have some initial testing done before I take off for the rallies, but I am looking forward to the back of my bike absorbing the bumps like the front.
Randy - RPM
Very cool Randy, Bring it on dude.....
Thanks for the info.
Unfortunately I don't think I'll be able to wait for the shock; After 85K miles mine is well and truly shot. Add that to the part where I have a 90 year old house to renovate (think lots of old plaster and wooden floors that need refinishing and you'll see the tip of the iceberg of what I have to work on) and a masters program I'm starting this summer and I'll have neither the time nor the finances to do this any time other than now. I can always revisit it when I have to do the recommended rebuild of the penske in 30K miles, which for me will be no longer than two years from now.
Randy
do you have any plans in the future for a kit for the YZF600 forks?...if not, I guess RT is still the only/best option there?
thanks
Louie
Randy,
Will the new shocks have ride height adjustability?
Will you offer a lower mounting for the earlier (non-dogbone, heim-joint) models?
DavidR.
Quote from: BSI on March 18, 2012, 11:10:31 PM
Randy
do you have any plans in the future for a kit for the YZF600 forks?...if not, I guess RT is still the only/best option there?
thanks
Louie
Louie,
I have no options at this point for another bike valves.
Randy - RPM
Guess what showed up today. I have the listed here; RPM Fork Valve (http://www.rpmracingca.com/proddetail.asp?prod=M%2FC%3ARPMForkValve)
The specified fork oil and springs are listed on the website as well.
Randy - RPM
Hey Randy,
Do I include my wingrack and cases in the "cargo" weight? I weigh 245lbs (and perhaps 255-260 ATTGATT) but I always have at least a top case on, or my side cases. Typically have a large bagster tank bag on the bike as well. I'm at the top of the range for the .90kg spring, and toward the lower end of the .95kg spring. What do you think?
Quote from: E Double on March 19, 2012, 09:54:28 PM
Hey Randy,
Do I include my wingrack and cases in the "cargo" weight? I weigh 245lbs (and perhaps 255-260 ATTGATT) but I always have at least a top case on, or my side cases. Typically have a large bagster tank bag on the bike as well. I'm at the top of the range for the .90kg spring, and toward the lower end of the .95kg spring. What do you think?
Well, we did the same thing on Mike Ramos' bike based on the auxiliary fuel tank & gear and he has had to adjust to the lightest pre-load with no ability to go lower.
We debated over this for quite a while and finally decide to try the heavier ones, but I was thinking the lighter ones. The reason I was thinking lighter was the fact the the rear luggage is behind the plane of the rear axle and falls more onto the rear spring than the front.
I would use the .90 as I think the weight is based on what is on the seat & tank, the tail should be considered for the rear spring, but ultimately it is going to be your call.
Randy - RPM
Hola Randy
Please, do I have to dismantle the forks to install the valves?
and can I use my Hagon fork springs or I have to change them?
Best regards
Alf
Quote from: Alf on March 20, 2012, 04:38:42 AM
Hola Randy
Please, do I have to dismantle the forks to install the valves?
and can I use my Hagon fork springs or I have to change them?
Best regards
Alf
No sir, the only modification you will have to make is cutting of the damper fork adjusting rod if you have one.
Here is the instructions: Drain the oil, refill with specified oil, install valves, set oil height, install specified springs and (cut "D" rod if you have one) screw the tops on.
Randy - RPM
oh man, where was i for the testing bit! lol.
this sounds like a very good investment. looks like i've got some saving up to do. fork brace, clutch, fork valves, etc.
A lot of questions have come across my email about the RPM fork valves. First off for those who have bought them and posted their results, I thank you and I am glad you are satisfied.
Here are two most common questions that are asked regarding springs & oil;
Q) "I already have a 1.00 spring, but by your rating I need a .90, do I need to change them?" (Or something very similar regarding spring rate)
A) The short answer is, Yes, you need the lighter springs.
The reason the fork springs need to be lighter is so they actually allow the fork to travel. The old school valves rely on the spring for support & travel control and they have to use a stiffer spring rate.
The RPM fork valve does not rely on the spring to act as part of the controlling motion and utilize it only as a spring, the valve does the controlling.
Now, with that said the stiff springs will work, but you will not get the full results of the RPM valve. The reason is, if the fork is not allowed to travel because the spring is too stiff, then the IAT valving can not activate because the spring is controlling the movement, not the valve which will result in a stiff & harsh ride.
The rating of the springs are based from the R-T specs, but if other spring manufactures have the same rating system then you can use whatever spring you want.
Q) Do I really need to use Motul oil you are selling?
Q) Can I use any synthetic fork oil?
Q) I already have XYZ brand syn fork oil can I use that?
Q) Why is the oil so light (5wt)?
A) Well, the short answer again is, Yes, The Motul Factory Race Team Line 5wt is the oil specified and should be used.
The same thing applies to the oil and it's viscosity. In the old days the fork oil was one of the controlling forces used with the spring to control the fork movement & performance. The RPM fork valve is now the controller of the fork movement and the heavier weight oils are only detrimental to the performance as it will not flow properly through the shim stack.
The shim stack contained within the valve is designed for use with the specified oil and flows properly based on the 5wt oil. The light weight oil also allows for a drop in use. The old school valves require the damper rod to be drilled, and that is for proper oil flow. The light weight oil will flow within the stock unmodified components without the need to drill and modify them.
If your damper rods are already drilled, you are okay, the RPM valve controls the oil flow, not the open holes of the damper rod and old school valve.
Now, the Motul brand oil. Fork oils are rated on an HVI index and the shim stack within the valve reacts differently to differing oils with a different HVI index. The closest oil in regard to the Motul HVI is Amsoil, and that would be the only other brand that could be used in place of the Motul, as it is within a few points of the Motul HVI index.
So, since the valve was designed before I came along with Motul oil and that is what the manufacture specifies, then that is the oil you should be using. The Motul "Expert" line is a blended oil and is not recommended.
These fork valves are part of a package that when paired together with all of the recommended components will give awesome performance, if you change part of the recommended package your results will vary.
I hope this answers the two most common questions, but if you have more please post them here or send me an email and I will answer them.
Randy - RPM
Thanks for the info on the fork spring issue Randy, it helps me to prioritize my upgrades.
Randy,
A few more technical questions.
If I install lower rate springs, then I'll have to use more preload to achieve the desired static and rider sag. How does the RPM valve compensate for what's going to be extra sag with the softer spring rate?
I understand what you're describing when you say you need to use a spring and oil combination that will let the forks travel and push enough oil around to activate the valve shims, but under extreme riding, can this lead to excessive fork travel?
As I comprehend suspension, the spring controls position and the valving/oil controls the velocity. There is some overlap, if you use a thick oil, it may slow the movement down enough to influence the position. Will I have more front end dive with the softer spring and thinner oil? If the valve controls position, then is sounds like if I push down or pull up, the suspension will "stick" in that position until acted upon by another force or input?
Is the shim response different in compression than rebound? Are they separately "tuneable?" Please don't take offense to this, but I'm kind of wary of a "one size fits all" solution to something as complicated and varying as suspension.
All that said, I am planning on getting a set of the valves as soon as I can figure out a way of paying for them without the wife knowing about it. :-)
DavidR.
Quote from: SlowOldGuy on April 04, 2012, 03:32:59 PM
Randy,
A few more technical questions.
1) If I install lower rate springs, then I'll have to use more preload to achieve the desired static and rider sag. How does the RPM valve compensate for what's going to be extra sag with the softer spring rate?
2) I understand what you're describing when you say you need to use a spring and oil combination that will let the forks travel and push enough oil around to activate the valve shims, but under extreme riding, can this lead to excessive fork travel?
3) As I comprehend suspension, the spring controls position and the valving/oil controls the velocity. There is some overlap, if you use a thick oil, it may slow the movement down enough to influence the position. Will I have more front end dive with the softer spring and thinner oil? If the valve controls position, then is sounds like if I push down or pull up, the suspension will "stick" in that position until acted upon by another force or input?
4) Is the shim response different in compression than rebound?
5) Are they separately "tuneable?" Please don't take offense to this, but I'm kind of wary of a "one size fits all" solution to something as complicated and varying as suspension.
All that said, I am planning on getting a set of the valves as soon as I can figure out a way of paying for them without the wife knowing about it. :-)
DavidR.
David, no offense throw out the questions and I will answer them or get the answer, but you have to throw away conventional suspension thinking with this product.
1) The valve does not compensate for the additional sag and that is the same with the measuring instructions included with the springs with & w/o rider. The valve has no control over sag and it should not( Unless you are running a race car and you want the shock to hold the car down and you built the rebound stack to be so stiff it cannot pass oil back through, like they did several years ago in NASCAR at the super-speedways)
I can say that it does take longer with the rider on the bike to achieve the sag measurement as the oil must pass through the shim stack. A helper to hold the bike upright is almost a requirement now.
2) No, the compression protion of the valve has two seperate valves which react to the input the fork is seeing, whether high speed or low speed travel (which I covered in the first post)
3) The spring as to allow the suspension to absorb bumps the valve is to control oil flow and spring compression & expansion rates.
4) Yes, the RPM fork valve has three different valve systems. It has the IAT (High speed; bumps) & shim stack (Low speed;cornering/sag) for compression and a shim/coil spring for rebound (Acceleration).
5) Yes, you can tune the valves with different shims and change the shim stack to suit your liking if needed. The IAT portion of the valve is not adjustable is is based off of the curb weight of the bike. The rebound portion is tunable, but it is set to allow the fastest rebound without allow the fork to employ the top out spring, that is also based off of the bike weight.
They sent me a tool when we were testing, but I have since sent it back. It is one of the things I have had thoughts of adding to inventory, but I figured it would be needed by someone who might be doing both track and road riding and the needed different valving for track.
Believe me, I played devils advocate on every aspect of the testing phase and the valve I am selling is the most complete RPM valve based on the weight of the bike. The spring rate based on the rider is the biggest adjustment required. Sure, 150 lbs rider could use a slightly different shim stack than the 300 lbs rider, but the difference in spring rate allows the shock travel to be the same based on the spring/rider weight. I tried the shim stack every way from Sunday and this is the best package for the "normal" rider. if someone is going to be tracking the bike then the shim stack might need some tuning, but the manufacture says they have a many guys using these valve in vintage events right of the shelf for the bike the purchase for and they have had great success.
Randy - RPM
David beat me to it, I'd been wondering the same things.....
Quote from: RichBaker on April 04, 2012, 09:08:35 PM
David beat me to it, I'd been wondering the same things.....
Are you still wondering...?
Randy - RPM
Nope...
I thought for a minute there Randy, you might be stocking Wondering now..... :lol:
Quote from: miked on April 05, 2012, 02:03:54 AM
I thought for a minute there Randy, you might be stocking Wondering now..... :lol:
:rofl: :rofl: :rofl: :rofl: :rofl: :rofl: :rofl:
Speaking of fork valves...
Well I will leave the technical answers to the gentleman from RPM but I do have three exhibits (actually two, as one shows the speedometer & tach) that show the front fork valves in action. And I trust that you may find the answers [or at least a few] to your questions in the videos...
The first video is of a section of a rather rough road with turns and a short straight. You can see the forks exceptionally quick up & down movement, regardless of their position in the stroke. They are not just cycling up and down, but fluctuate sharply whether under deceleration (under compression) or acceleration, actually "dropping" into an imperfection in the road surface.
While the turn speeds are modest, there are moments when the forks are responding quite nicely under the added loading of the forces encountered when leaning through a turn.
The second video is of the speedometer (and I apologize for the shakiness; the mount was free standing about a foot off of the tank – I will have a better position the next time I try this). I ran the exact same stretch of road at the same speed, more or less. The speeds are of the low and intermediate range, but I can attest to the fact that at the higher speeds the results of the fork action are quite similar.
The third video (without the engine sounds) of another road I came across in an earlier video about another country road. It is hard to tell in the video, but the rear shock was limiting my enjoyment...
Easter is near. Does the Easter Bunny leave rear shocks in the basket? Here comes Peter Cottontail hopping up the bunny trail...
I sure hope I don't have to wait 'till Christmas...!
Ride safe,
Mike Ramos.
Front Fork (http://www.youtube.com/watch?v=S8tEv11d8oA#ws)
Approximate Speeds_Gauges (http://www.youtube.com/watch?v=wQP33Rt4iEM#ws)
More of the Same (http://www.youtube.com/watch?v=YiMd02e3RZI#ws)
A little technical difficulty with that third video. You should be able to see it here...
More of the Same2 (http://www.youtube.com/watch?v=f9kSC4yLT7o#ws)
Randy ,
I helped Craig install his RPM fork valves and springs this weekend and have a few follow up questions about them.
1.what is the recommended static sag ?
2.what is the recommended rider sag?
3.what is the recommended oil level with forks compressed and the valves and springs out from the top of fork, down to the oil? 130mm?
4.what is the proper placement of the washers for the fork springs ? is one needed on top of the fork valve? or just the spacer ends?
I understand the fork valves are pre adjusted and go in only one way with the long part up, but is there an adjustment necessary for a more spirited rider? more oil? or 1 turn of the adjuster nut?
As it stands the noise from the front end sounds like a old whores bed springs.
does everything just need time to settle in?
I may have overdone the preload. :blush:
Mark O.
I will be interested to hear others reply on these questions Mark. For me its .25 inch static and an additional .5 inch with rider so from full "top out" of the travel it should be .75 inch with the rider on..... can't offer any other info on the remaining questions.
Tim
Quote from: Mark Olson on April 29, 2012, 12:51:44 PM
1.what is the recommended static sag ?
2.what is the recommended rider sag?
3.what is the recommended oil level with forks compressed and the valves and springs out from the top of fork, down to the oil? 130mm?
4.what is the proper placement of the washers for the fork springs ? is one needed on top of the fork valve? or just the spacer ends?
I understand the fork valves are pre adjusted and go in only one way with the long part up, but is there an adjustment necessary for a more spirited rider? more oil? or 1 turn of the adjuster nut?
As it stands the noise from the front end sounds like a old whores bed springs.
does everything just need time to settle in?
I may have overdone the preload. :blush:
Mark O.
1) The "static sag" is as recommended in the spring installation instructions:
25-30mm2) What is rider sag?
3) As listed in the RPM fork valve installation instructions:
6" or 152mm*4) Washers are only required at each end of the spacer. If you have the stock washer at the top, the additional spacer included with the spring is not required.
The spring pre-load should be 15-20mm (as specified in the spring installation instructions)
I have heard that as well, but after they settle the noise is less, but there is still some noise. It comes from the spring actually being compressed and rubbing against the inner wall of the fork tube and the thin oil. That was something you could not do with the other valves...
*The oil level can and will continue be a tuning tool. There is not an adjust of the valve without complete disassembly. The nut on the top is holding it all together it is not a tuning adjustment. If you feel you need to tune the valve, I will have the tool and shims available after I get the next order so you can play with the shim stack.
Randy - RPM
Static sag is the amount the bike squishes the suspension under its own weight. Rider sag is the same thing but with the rider in full gear on the bike.....
You can measure static by pulling up and the front or rear end and measure how much it lifts before the suspension tops out.
I think the 25-30MM would be the Rider Sag amount - close to what I was saying at 3/4 inch or 19.2mm. I am told that on a properly adjusted bike the sag is the same front and rear....
tim
Quote from: axiom-r on April 29, 2012, 02:45:31 PM
Static sag is the amount the bike squishes the suspension under its own weight. Rider sag is the same thing but with the rider in full gear on the bike.....
I do not want to confuse the subject, but not according to the spring manufacture installation instructions. They list "
static sag" as the
"amount the bike settles, from fully extended, with the rider on board in riding position".
That is why in the RPM fork valve installation instructions it says to follow spring manufactures installation procedures.
Randy - RPM
BOTH are static sag. One is BIKE sag the other is RIDER sag.
This is still a confusing issue I have. My 0.95 springs give me the correct rider and bike sag. If I go to a softer spring and adjust for rider sag then the bike sag will be wrong (probably too small since the softer spring will require lots of preload to achieve required rider sag).
DavidR.
Agreed Randy- sorry to have complicated the discussion. It is confusing though! DavidR hit it- it is all "static sag". I get my info and instruction from some buddies that are competitive racers and they helped me to dial in my suspension. I think their range is more closely suited to sport or track conditions and I was hoping to hear what sag range might be better suited for sport touring or just touring.... DavidR, the way these guys do it is they set the preload to where the bike is squatting about a quarter inch all by itself under its own weight then adjust further to set sag with the rider on. The more critical issue is Rider Sag so if need be just focus on setting your preload for that. When you have it close do some compressions standing next to the bike- if it "bumps" (hits the top) when you do a quick release from compression you have too much preload..
My bike currently sags the .25 inch and then drops another .5 when I get on... thus the .75 just a bit less than what you were indicating Randy so I think that translates to a firmer suspension with a bit more preload. I may try baking off preload a bit and letting the sag increase to the range you are indicating and see where it gets me...
cheers-
Tim
Quote from: racerrad8 on April 29, 2012, 02:37:12 PM
Quote from: Mark Olson on April 29, 2012, 12:51:44 PM
1.what is the recommended static sag ?
2.what is the recommended rider sag?
3.what is the recommended oil level with forks compressed and the valves and springs out from the top of fork, down to the oil? 130mm?
4.what is the proper placement of the washers for the fork springs ? is one needed on top of the fork valve? or just the spacer ends?
I understand the fork valves are pre adjusted and go in only one way with the long part up, but is there an adjustment necessary for a more spirited rider? more oil? or 1 turn of the adjuster nut?
As it stands the noise from the front end sounds like a old whores bed springs.
does everything just need time to settle in?
I may have overdone the preload. :blush:
Mark O.
1) The "static sag" is as recommended in the spring installation instructions: 25-30mm
2) What is rider sag?
3) As listed in the RPM fork valve installation instructions: 6" or 152mm*
4) Washers are only required at each end of the spacer. If you have the stock washer at the top, the additional spacer included with the spring is not required.
The spring pre-load should be 15-20mm (as specified in the spring installation instructions)
I have heard that as well, but after they settle the noise is less, but there is still some noise. It comes from the spring actually being compressed and rubbing against the inner wall of the fork tube and the thin oil. That was something you could not do with the other valves...
*The oil level can and will continue be a tuning tool. There is not an adjust of the valve without complete disassembly. The nut on the top is holding it all together it is not a tuning adjustment. If you feel you need to tune the valve, I will have the tool and shims available after I get the next order so you can play with the shim stack.
Randy - RPM
thanks for the replies.
1. bike only drop
2. rider and gear
3.there where no instructions with the valves ,they were just shipped in the race tech spring box according to Craig , maybe he lost them?
so I have way too much oil ? where is this measurement taken from?
4.so the spring sits directly on the RPM valve?
just trying to be clear ,I was working with no instructions and just copied what I remembered when I installed race-tech on my fj.
Mark O.
Quote from: Mark Olson on April 29, 2012, 06:30:31 PM
thanks for the replies.
1. bike only drop
2. rider and gear
3.there where no instructions with the valves ,they were just shipped in the race tech spring box according to Craig , maybe he lost them?
so I have way too much oil ? where is this measurement taken from?
4.so the spring sits directly on the RPM valve?
just trying to be clear ,I was working with no instructions and just copied what I remembered when I installed race-tech on my fj.
Mark O.
Yep after we talked, my shipping department must have omitted the instructions, sorry to create the confusion. :ireful:
I am grooming him to help, but the little things seem to be the hardest... :flag_of_truce:
I emailed them to both of you and hopefully the process will finish much smoother. :good2:
Randy - RPM
Randy,
I know that you've done CONSIDERABLE testing to get the right valves for the FJ, but I KNOW you've been asked or have yourself considered applying these to other bikes: dirt bikes, in this instance. I was describing your valves to a friend who runs an '81 YZ250 in a vintage class and we were WONDERING :biggrin: if they can be adapted. I believe that bike runs 43 mm forks but just askin...
Thanks and I'll take my answer off the air...
Ryan
Fork valve update,
Removed the extra washer and adjusted the oil level to 6" and adjusted the pre-load on the spacers, set the d-rod adj to medium as per instructions .
current sag with rider is 27mm.
too much pre-load and too much oil before.
feels much better , gonna run it for a while and check out the numbers after it all settles in. :good2:
Hi Folks,
Having ordered up the fork valves and springs shortly after they hit the market and installing them as soon as they arrived (which was like 3 days after I ordered them, thanks to Randy's quick turnaround with shipping), the weather and work decided to conspire against me getting some quality seat time to test them out. That was until this weekend. So now that I've got some miles on the them, I thought I would offer my impressions. Note that I am in no way skilled at suspension work or tuning, I generally follow instructions and hope for the best when it comes to these sorts of things.
For starters, as noted the parts arrived very quickly and for the most part in excellent shape. The only thing I noted on the one of the valves is that the allen head on the bolt was a little wallowed out, which didn't look like would affect anything, so into the forks they went. Installation was easy, the forks weren't leaking so I left them on the bike, just drained them, pumped them up and down a couple times the get as much of the old fluid out, added the new oil, dropped in the valves, springs, spacers and washers and sealed them back up (I've got a '93, so no 'D' rod mod). My only concern with the install was that the valves slid freely down the oil and only required very light pressure with the spring to get them through the oil and seated. For some reason, I assumed they would be a tighter fit but a quick email to Randy eased my mind.
I should note that the majority of my riding is touring in nature and predominantly in a straight line, not a lot of curves or fun roads in SE Michigan. I'm mostly concerned with comfort over our rough roads. I put about a 150 miles on them today on all manner of roads and have to say overall they are quite an improvement over my old springs. I'm not sure what the old springs were, they were progressive but not stock as they had +/- 4" long pvc pipe spacers installed to get preload, no markings on them. Anyways, my experience so far is that the forks seem much more compliant over large cracks / potholes and sharp bumps. The ride is super smooth on the expressway, they seem to work better the faster I am traveling. I don't even notice going over big cracks or wide expansion joints on overpasses. I played around a bit with the preload by using the adjusters in the caps and settled with the adjuster at 1 notch in from all the way out. If I went in 2 notches, the ride became noticeably harsh on the highway. I haven't measure sag yet, so I'm sure where that's at. I noted that the forks performed better the sharper the profile of the bump was. I'm assuming that has to do with the inertia valve opening and allowing fluid to bypass the shims.
The only issue the new setup didn't resolve are the large "humps" in a lot of the roads around here. They're not sharp bumps, but rather tall and wide humps that the bike rides up, over, and back down rather than absorbing, mostly on surface streets with speeds around 40MPH. I'm not sure if anything would be able to absorb them given their profile. I wonder if a lighter spring rate, or less oil to allow more compression of the shock would help with these humps, though I'd hate to go too soft and run the risk of bottoming out.
Overall I give the new fork valve / straight rate spring kit two big thumbs up :good: :good: I'd like to thank Randy for putting in the effort to develop these, and to all the group members that had a hand in their testing and refinement.
Thanks Fellas!
mickey
Quote from: soundmindryan on May 03, 2012, 04:12:40 PM
Randy,
I know that you've done CONSIDERABLE testing to get the right valves for the FJ, but I KNOW you've been asked or have yourself considered applying these to other bikes: dirt bikes, in this instance. I was describing your valves to a friend who runs an '81 YZ250 in a vintage class and we were WONDERING :biggrin: if they can be adapted. I believe that bike runs 43 mm forks but just askin...
Thanks and I'll take my answer off the air...
Ryan
I have inquired but I have not heard back yet.
A couple of things I need to know;
Bike weight
Current spring rate
I.D. of the fork tube
The wall thickness of the FJ tubes required a set to be specifically made for the FJ, but they do offer many other street & Dual sport valves that might be able to drop right in.
Randy - RPM
Thanks Mickey,
I am glad you are happy with the valves. You can definitely play with the oil level to see of you can get the undulations under control. I do not recall what spring you ordered, but the better the fork can move, the better the valve works. If you are close to a break point of the spring rate, then go with the lighter spring,
I can honestly say that I do not even look at the valves before I send them out as they are sealed in the bag from the manufacture. The hex use used during the building of the unit and does not affect the operation.
I will check my others and let the manufacture know if the issue as well.
Thanks again,
Randy - RPM
I ordered the 0.90kg springs and am at the bottom end of the weight spectrum for them all geared up. I went with the 0.90 because I tend to take long trips with a fair amount gear on the back of the bike weighing it down. Didn't have any luggage on for the test ride though. Maybe I need to get the softer springs for day trips and keep the 0.90's for the longer trips. Only takes a few minute takes to swap them...worth considering.