RPM Fork Valves

[racerrad8]

"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

[E Double]

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!

[racerrad8]

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

[FJmonkey]

Very cool Randy, Bring it on dude.....

[E Double]

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.

[BSI]

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

[SlowOldGuy]

Randy,
Will the new shocks have ride height adjustability?
Will you offer a lower mounting for the earlier (non-dogbone, heim-joint) models?

DavidR.

[racerrad8]

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

[racerrad8]

Guess what showed up today. I have the listed here; RPM Fork Valve

The specified fork oil and springs are listed on the website as well.

Randy - RPM

[E Double]

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?

[racerrad8]

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

[Alf]

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

[racerrad8]

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

[wakdady]

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.

[racerrad8]

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