Merge RRS Review - Part 2

Product Tested: Merge RRS KYB "MX" Version
Test Bike: 2005 YZ250, .42 Fork Springs, 240cc oil amount

With the technical mumbo jumbo out of the way, the important information can now be addressed.

How they work!

The first track chosen for testing was a sand base, and as such, gets very rough. It does, however, have patches of clay mixed throughout (originally brought in for jump faces) that form to make extremely sharp, "square edged" bumps. Because of the extremely rough nature of the track, and the variety of bumps, it was felt the track provided an excellent test bed for the product.

The second track chosen was a clay based track that doesn't get nearly as rough as the other, but has a more Supercross style jump set up, requiring settings much different than the first track.

The primary test riders included a 150 pound pro, a 145 pound intermediate, and a 165 pound novice.

Initial "crack of the throttle" Impression

Having successfully installed the product, it was now time for the fun! Any time riding is a good time riding, and after making one last check that the fork caps were secured properly to avoid certain disaster, it was time to hit the track!

Like most first laps, the first one for each test rider was spent cruising around to get a feel for the track. Surprisingly, it was instantly evident that a change had been made. The riders noted that the bike was much more responsive to movement just rolling to and from the pits on the little bumps and rocks, and while scoping the track, the forks actually absorbed small little chop which was not the previous case.

If you have ever ridden (or are a rider of) a bike set up for an intermediate and up rider, the suspension typically feels fairly harsh when just cruising around the track. This is because at race speed, the suspension needs to be stiff enough to work well, but when traveling slow, it is too stiff to absorb the bumps.

Every tester noted that when just rolling around the forks felt much more supple.

The Problem

BUT! While having a smooth ride in and out of the pits is great, it doesn't mean squat when it comes time to to get down and dirty. When its time to race, your suspension is the number one mechanical element to good lap times, and poor performance in this department can ruin an otherwise good day.

Prior to servicing the forks, (fresh oils, bushings, seals), the bike was a constant compromise for each rider, and a nightmare invoking beast for one in particular! . There was no doubt that it needed help, as in order to keep the bike from bottoming, the compression had to be increased greatly, but once that was performed, it was much to harsh on braking and acceleration bumps.

Some testers even said while under heavy acceleration, in instances where the front wheel was barely contacting the ground, even the smallest of bumps could induce minor head-shake.

Many readers might feel it wasn't stiff enough, and as such was that it was deep in the stroke, but every tester tried the gambit of settings, and adding compression only compounded the issue. One click literally meant the difference between a harsh "clank" four times a lap or terrible deflection on bumps and an overall harsh feeling.

Post fork rebuild, and after much oil height and adjuster tuning, the forks worked much better. That said, bottoming control and initial bump compliance were still lacking.

So what are the answers to any and all

questions on the RRS Springs!?!

Can its design be improved?

Yes.

As supplied, the product appears of excellent craftsmanship and consistency. Both springs are of equal length (a must) and free of burs and/or pits etc...

That said, the installation instructions call to merely remove the piston assembly, replace the springs, and re-insert the piston assembly into the forks, as shown on the video in part one.

Many feel there are errors in this method, as air will get trapped between the floating piston and the cartridge oil. That condition is believed to lead to extremely poor performance for many.

In light of that fact, the springs were installed on a second occasion, using the correct procedures in order to bleed the inner chamber, in order to get an accurate test impression.


Was there a difference between the two installation methods?

Surprisingly, not as much as one would expect. Every test rider noted a somewhat more consistent feel once installed the second time, however the difference was minimal. Lets be honest, 2 cc of air in relation to the rest of the fork's elements won't mean the difference between a hydro locked condition, or a pogo stick, especially on a track with large braking bumps that constantly uses your forks whole range of travel. It is possible [Ed: emphasis on the word possible] that the inner chamber self bleeds upon first bottom as well.

While the clay based track never got back to back testing between the two installation methods, everyone felt that using the supplied installation technique at that track in particular would have been much more noticeable, as the bumps were much smaller and used the very first initial part of the stroke.


However, to ensure that the average consumer installs this product correctly, it is highly recommended that you completely remove the inner chamber and install the product in that manner. This is where Merge can definitely improve their product. Their supplied installation instructions should take this into account, and as such we felt they should update their procedure.

That changes the installation difficulty fro m a 5 to a 7 for average Joe.


How well do they work?

The Merge RRS springs were an interesting product. Just to get it out of the way, without changing any adjustments, bottoming was no longer an issue. Every test rider experienced none of the previous issues with bottoming control as once prevalent to the bike. One rider (yeah that guy), however, managed to over jump a large up hill double straight into a sharp hole.

Here is his recount:

"I thought I was nearly going to break my wrists!" he said.

"After getting real stiff and squeezing the crap out of the sides of the bike, my brain starting wandering! I kid you not I was up there, I mean I had enough time to think what hospital was gonna fix my wrists! Don't know WHAT I was thinking going up the face, but anyways, after puckering the ole' balloon knot, the bike pounded straight into the hole. I was scared, but it completely surprised me with barely a "clink" and practically no hard hit to my wrists. Talk about way different than it used to be..."

Everyone was glad he was fine, as that double could definitely bite you.

(not actual test photo)

While every tester was excited about the increased bottoming resistance, the braking bumps are what really matter to most riders. Here each tester stated that the bike worked well.

The biggest difference noted was under heavy acceleration. The front wheel no longer skipped and darted, instead actually absorbing the small chop under heavy power. Head-shake was no longer experienced by any test rider with the RRS installed. But there may be a reason for this....and the adjustments portion may shed some light in this area.

Obviously, using that information, one can conclude the bike was much more compliant to initial movement. When before it would deflect and feel harsh on bumps, it now moved with the ground much better. Each rider felt they experienced much less arm pump than before.

When the test riders were probed for further information, there wasn't much to be had. The bike worked well, period.

Was it the best suspension they had ever ridden? No.

What would they improve? Nothing, really...

So its fine then? Yeah...its good, no complaints.

One pro rider, who typically rides a bike with completely reworked suspension from one of the "giants" in suspension, including fork sub tanks (he is a pro...of course his suspension is re-valved), commented that the suspension didn't feel too far off from from his, and with some minor tuning it could be raced hard with no issues.

Was it as good as his? No.

The real tale of the Merge RRS springs is exactly that. They aren't earth shattering by themselves. That said, when no test rider has any complaints, the suspension has to be doing its job.

Considering where the suspension was prior to installation, that is a huge improvement.

What Adjustments Should I make after Installing the Merge Springs?

Who knows! Every rider is unique, but if your set up was close prior to installing the springs, it will be close after installing the springs.

With bottoming control no longer an issue, most test riders went in the softer direction with the compression.

This may have allowed the bike to absorb the small chop better than before, not merely the springs. The Merge Rising Rate springs are directly attributed with this overall improvement. With the RRS installed, softer compression settings were allowed, giving better overall initial movement. Previously, to get the same level of small chop compliance as possible with the RRS, the soft compression setting would lead to a harsh "clank" 3-4 times a lap.

Are they worth the money?

At a retail cost of 60 dollars even, the Merge RRS springs are not expensive in relation to a re-valve. Compared to your typical ICS spring, however, they come at much higher price.

If your on the fence, and are already considering purchasing the RRS springs, think of it this way. The sacrifice is basically skipping one race weekend, saving that money, and putting it towards these springs.

At your next race, you will greatly appreciate the purchase.

The real question is, are they staying in the owner's bike?

Yes, they perform much better than stock.

Don't expect a miracle, however. Nothing can compare to getting your suspension's spring weights and valving correct for your ability. If you feel your suspension is close already (at least the correct spring rates) , the Merge RRS will improve your suspension's performance.

The Bottom Line

Merge provides a well made product, with solid performance gains that you can feel. What else can you spend 60 bucks on and get a noticeable performance gain?

In that light, using a cost to performance rating, EternaltwoStroke.com is confident in giving the Merge Racing Technologies a 4/5 rating.

The installation difficulty and lack of instructions to perform complete inner chamber removal are the only things holding the Merge RRS from a 5/5 rating.

Product Review: Merge's Rising Rate Springs - Part 1

Merge Racing Technologies first made ripples in the racing community with its release of their adjustable leak jet. While the product hasn't revolutionized motorcycles, it has greatly improved in an area lacking with the modern surge in four stroke motorcycle sales. The dreaded “bog”. The ripples slowly built into waves, as many of the top 20 riders in the country started using the product and having great success with it during the 2008 Supercross and now Motocross season.

But a company can't exist merely on one product, and that brings us today.
The one mythical area on most rider's bikes has always been its suspension. Most riders never even venture into touching their suspension, let alone adjusting its internals or oil levels. Instead, they rely on various companies to rebuild, perform seal replacements, and ultimately re-valve their stock components to obtain their desired ride.

Merge Racing Technologies' offers a truly unique product in their Rising Rate Springs, or RRS for short.

[Ed Note: This is a very simplified technical explanation - techies: take it easy!]. The modern forks on race bikes are a “twin chamber” design, with an internal damping system that resembles a typical rear shock in design. While there are some differences your fork's design vs. your shock, one major difference is the lack of a nitrogen reservoir. Instead, to make up for the lack of a nitrogen reservoir, modern twin chamber forks use a spring. This spring is commonly referred to the ICS spring.

Why do ICS springs and Nitrogen

reservoirs exist?

When the shock shaft enters the shock body, it displaces a volume of fluid equal to its own volume. This fluid has to go somewhere, and thus a pressurized chamber is provided. The fluid is allowed to enter a chamber as the shaft compresses, but as the shaft rebounds the fluid returns.

The nitrogen and ICS springs maintain a positive pressure on the fluid at all times to prevent tiny air bubbles from forming in the oil while also providing an additional spring action. The farther the shaft enters the stiffer it gets. The nitrogen reservoir and ICS spring are purely position sensitive.

Many people feel that the ICS springs act only in combination with your main fork spring and the air spring adjusted by your oil height.

However, depending on velocity conditions, the ICS springs also effect what part of the valving gets used: if the fluid velocities are high enough, it can't find its way through the low speed part of your valving fast enough. It then transitions to the "mid valve" or rebound side of your piston.

To quote Hooligan, one of the partners at Merge, from thumpertalk.com,

"Here is a quick explanation on how they work - When you run a really light pressure spring the piston below it moves easily and the inwards (compression) damping force is controlled by the oil going through the upper piston holes, the shim stack that covers these holes and bypass holes in the piston (not covered by shims and inc the compression adjuster). The stiffer the pressure spring the more resistance on the floating piston, this in turn forces the oil through the shims on the bottom of the rebound piston (attached to the damper rod AKA “Mid Speed Valve”). You need to enough mid speed to slow the fork down over big hits so it doesn’t bottom but, too much mid speed is one of the most common causes of harshness."

Yeah, what he said.

Since their inception, tuners have been exchanging these ICS springs in favor for ones with lighter spring rates claiming much better small bump compliance and better overall performance. However, they are a compromise. By allowing better small bump compliance, bottoming resistance is lessened to some extent, and the risk of cavitation (tiny air bubbles in the oil) increases. While a good tuner can circumvent the bottoming issue and possible poor high speed damping performance by using other elements of the fork's systems, merely swapping your current ICS springs for lighter ones may not be the end all be all answer, and the risk of worse performance lingers.

Instead of merely offering a lighter spring, Merge Racing has brought a new concept to the table with their progressive ICS spring. According to Merge, this is the “linkage for your forks”, and by using a little engineering, the springs are wound and tapered in such a manner that they have a progressive spring rate.

What's a progressive spring rate?

Most springs are categorized in a manner such as kg/mm, or something similar in different units of measure.

For example, a spring with a 1kg/mm rate means as follows.

To compress the spring 1mm, and it requires

1kg of force, to compress it 2 mm it requires 2kg of force, and for 3mm it requires 3kg of force.

But the RRS spring is different.

To compress it 1mm and it may require .5 kg, but to compress is 2 mm it may then require 2kg of force, and then on 3mm and it may require 3.6kg and so on.

As you can see, the progressive spring is not linear, as opposed to normal springs.

Installation

Installation seemed difficult to say the least. Not only would it require removal of the fork inner parts, but it required removal of the important fork internals. At this point, the intimidation factor was at a 10. But after referring to supplied instructions, and taking a leap of faith, installation was actually a cinch.

Watch the video to see it Installed...kinda

Installation difficulty (1-10): 5

Its smack dab in the middle between: Installing an exhaust and changing a tire.
Make sure you use the correct tools.

Stay tuned on EternaltwoStroke.com for part two and find these, and many more, answers out:

Does it work?

Is it worth the money?

Can its design be improved?

A Linkage you say....

What adjustments must one make to best optimize its installation?

Freestone MX - Smaller and Worse?

In its second running, the Freestone national yet again provided Texas natives a wonderful opportunity to watch, in the flesh, some of the fastest motocross riders do battle for a total of 60 minutes and four laps in each division. That is a total of 120 minutes, plus 8 laps of action, not even counting morning practice or the WMA race! So strap on your reading glasses, and start scanning from left to right, top to bottom to learn what the real Freestone race experience was like, along with some scattered perspective from your truest fan, average Joe.

**********************************

"Excuse me ma'am, but where exactly is the track?" Joe inquires to the lady behind the convenience store register.

"Go right just out here, and follow the signs" she starts, "oh! and a friendly Texas tip, use the second entrance posted."

Joe darted out the convenience store and opened the door to his truck. Just before climbing in to his lifted Ram 2500 diesel, he froze.

"Crap, I forgot my stuff!" he exclaimed to the register lady after darting back in the store. He was so smitten with excitement he forgot his drinks and ice.

**********************************

The Freestone track looked, for the most part, unchanged from the previous year, save a few minor modifications intended at fixing some of the one lined sections in its previous inaugural year. The dirt looked extremely tacky, and seemed to make some awesome ruts in the first motos: quite honestly, I think some of the race report photo's are over saturated (or something like that - or too bright) and made the dirt look somewhat hard packed, but in person it was a sandy loam that packed up well to form ruts.

**********************************

"Howdy! Welcome to Freestone, you guys need tickets for today?" asked a young man standing out in the beating sun at the track entrance.

"You know it! How much each?" asked Joe.

"35 a piece, but I'll take 40!" he replied

"Haha, I can give you a 40, but its not cash if you catch my drift" Joe states.

He leans over, removes his wallet, and carefully removes his money. He then turns and collects the trucks occupants share, and hands it to the young fellow.

"WOOOOOOOHOOOOOOOOO!!!!!!! THE NATIONALS BABY!" Joe shouts as he enters the premises.

**********************************

If you watched the first lites moto, you would know that RV1 is fast. But if you didn't, you missed something special. Vill-"OH my god!"-poto was riding on mission, and from what can be gathered, really enjoyed the Texas track. If you were the competition, that had to be bad news: The dominant rider on a track he likes. RV's style is completely his own, and if you pay attention, you will notice he keeps his feet on the pegs much more than other riders, rarely sticking his leg out in corners. It is unique, amazing to watch, and must require cornering balance that few other riders possess.

Austin Stroupe showed some excellent speed, but when Dungey started creeping into his picture, Stroupy made a mistake, and fell. He quickly remounted and put on a charge that had to make Mitch Payton happy, but no matter how hard he pushed, Dungey stayed a few bike lengths ahead. Those two are in for many battles to come, as in the second moto, a similar story was played out.

The Jason Lawrence Show - or is it The Jason Lawrence No Show? After reportedly nearly getting arrested the night before during the pitbike races for minor in possession/consumption along with his good buddy Josh "King of the" Hill, J-Law looked strong in the first moto, but didn't have the speed of Dungey, Stroupe, or Vill-"OH my god!"-poto.

In the second moto, J-law's sponsors couldn't have been happy, as he wrecked in the whoops and called it a day. Some might argue the Texas heat and a hang over don't go hand in hand, but there is no credibility to those statements. While Jason - the law - Lawrence may make his own rules, Texas law isn't so lenient on its policies, and there still may be some fall out from his little debacle.

**********************************

"WOW! YOU SEE THAT?! Vill-"OH my god!"-poto NEVER SHUT OFF THAT WHOLE SWEEPER!" Joe yelled over the thundering bikes. "I DON"T KNOW HOW HE DID THAT!? HE MAKES ME LOOK LIKE I NEED TRAINING WHEELS!" "DUDE, THE PRO CIRCUIT BIKES ARE REALLY LOUD. IT HONESTLY HURTS MY EARS, I HAVE NO IDEA HOW THEY PASS SOUND INSPECTION. HELL, LOOK AT THEIR SILENCER, IT IS WAY SHORTER, IT BARELY GOES PAST THE SIDE PLATE." He yelled again.

**********************************

In the motocross class, Stewart was king yet again. He really does look like a new rider this year, as many people were commenting on how smooth he looked. In fact, to quote Joe, "He looks slow, how in the heck is he putting distance on Alessi?"

That said, he was faster than greased snot. Watching closely, it became apparent that he chooses better lines and carries his speed everywhere. He looks slower because he hits the brakes less, and in turn uses the throttle less. He basically does less slowing down any other rider, and thus needs to accelerate less to maintain his speed. It is quite deceiving!

**********************************

During the first couple of laps in moto one, Alessi was in front of Stewart.
"What's up with Alessi this year!??! He looks like someone stuck a bottle rocket in his ass this year --- He is railing, dude!" Joe says during the much quieter 450 main event.
"All I know is he looks way better than everyone else, I mean where the heck is Short? He killed it at this track last year, but he looks off or something..."

Then the number 105 on a worn out looking bike flew by, head down charging full tilt ahead.
"DUDE! That is Sean Hamblin! He is doing awesome this year for a privateer!" but five minutes later Joe sees a very frustrated Hamblin pushing his bike towards the pits after a grueling 30 minutes and one lap into the first moto.

"That BLOWS, dude, I can't believe his bike didn't make it, but on the last lap no less!"

Then Josh "King of the" Hill rolls by, his clutch complete toast, and Joe says, "why is it that Yamaha makes the most reliable stock bike, but can't even get their race bike to do 30 minutes without breaking?!!? I would be so pissed."

**********************************

The Texas heat was the real story, and if you just started reading, pay attention. Texas is a huge state, and likewise, it has a lot of inhabitants. With Texas also being the hotbed of amateur motocross, combined with its large population, one would think the fan turn out would be superb.

Think again.

While the turn out was nothing to scoff at, I don't think it was quite what the Miller family is looking for. Combine the typical Texas heat and untypical humidity with a track that has extremely limited fan visibility, and you get a recipe for lack luster fan support. Not only were the fans somewhat limited in number, but limited in enthusiasm. But who can blame them! The heat was something to remember, sapping the energy of everyone, riders included.

The riders. Is it just me, or are some of the up coming professional riders being complete wusses? Maybe they are too young to remember, but nationals have been to Texas for many years in a time long, long ago, and those pro's managed to deal with it. Even the amateur racing community saddles up week in a week out to go ride in the heat, and it doesn't seem to be too huge a problem. But what IS a huge problem is when only 24 riders complete the second lites moto. Fans don't pay to watch some kid roll around the track for three laps before pulling off. If you didn't read it, read this on timed qualifying. It may have to do a little something with our riders dropping like a bag of bricks from the empire state building.

That said, Brett Metcalf manned up and gritted out what must have been the hardest couple of laps in his life, followed by his collapse after the finish line checkers from heat exhaustion.

Now THAT is a motocrosser. Other riders who dropped out, take the Metty notes, he deserves that Payton ride just for that.

**********************************

"Wow, look look look, there goes Robbie Reynard! I remember when he came to our local track on a Canondale, and dominated some pretty big name riders by like 30 seconds each moto. Considering the bike was crap, that was a sight to be seen!" Joe exclaims with genuine respect and excitement.

As Stewart entered the treacherous Texas Twelve Pack of whoops for yet another pass, Joe's asshole puckered up tight. "GAWD DANG! He scares me there, I mean shoot, he is ONE HUNDRED percent committed entering those things, and at that speed, one tiny mishap....and we would be saying remember that James Stewart kid? But he does it every lap no less, guess he has it dialed." he said.

After watching Reynard put in some of the smoothest riding on earth, Joe says "But he looks slow here today, I don't think he will crack the top twenty, even if he gets lucky."

As the moto winds down, Joe can just hear the race announcer calling out the finishing positions as the moto ended "...and Reynard crosses the line in 13th! That has got to be something he is proud of..."

Joe, straining to listen, tries to process what he has heard. "NO WAY! He looked smoother than glass, but slow as molasses. Man, he has got to be the smoothest rider on earth! How in the heck does he ever get hurt! I can't believe that! Well, great ride for him, I am truly impressed."

**********************************

All said and done, the Texas national was a success, but by a different needle and main jet combination. The race finally put the word Manly back into motocross, and it separated the cream from the milk. Texas fans were treated to what had to be some of the finest riders in the world, and it helped spur dreams for hundreds of young kids to aspire to. Be sure to attend your local national, because if you don't we won't have any nationals to attend to.