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.
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.
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