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  • #16
    By referring to JD, I mean JD Hord of hordpower.com, vendor and supporter of our RC31. The main problem is that you need to make a plan and stick with it, it is not a good idea to mix from different setups. So without Racetech Emulators and with some unknown springs, you need to begin by finding out exactly what the springs you have are - eg. linear, two-step or progressive. And if linear, which rate and for the other two, what does the rate-curve look like? If you are going to keep the damping rods stock, you should start with a stock'ish setup. Eg. some fork oil of around 30 to 40 cSt, brand and type not really important, especially for a stock'ish setup - it becomes more important when using cartridges or separating the damping circuits, eg. by using Racetech Emulators or cartridges. Choose a fairly low oil level as it is easier to fill than take out oil from mounted forks and in general it is best to start from the softer side.

    Best way to work with the forks is to follow the workshop manual and familiarise yourself with the microfiche drawings. Then read the how-to sections on this site and the best way to search for threads is to use google, site hawkgtforum, relevant search items (eg. stock forks, viscosity, oil level)

    There are many threads on forks on this site and many good contributions from JD (Hord, hordpower) wildwhl (ww) JB riot SPA melmsrt4 and lots more so look around...

    You might be satisfied with the stock'ish setup, but also might need to have to do a couple of iterations and play with oil viscosity, oil level, preload etc.

    It is much easier to go to a known setup like the one hordpower sells, which includes springs, oil and emulators and setup instructions.

    I don't really work on stock forks so can't really give more specific recommendations.
    Last edited by JanM; 01-18-2018, 01:06 PM. Reason: typo

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    • #17
      So, finally I have gotten around to do a few things... work is being a pain in the arse leaving little time for the fun stuff, as well as the weather in Ireland is complete shaite.
      But enough bitching and complaining, I have so far taken the clutch out and looked over the all the components, replaced the springs, friction and steel plates which resulted in one heck of a difference. The bike behaves very nicely and seems quicker with the new clutch from Barrett! I also replaced the clutch cable (again) just to be sure. Then I got the bike up on some jack stands, that operation deserves a chapter of its own. Me holding up the front end while the better half is trying to raise the jacks, trust me there was a lot of "can you hold it up for 10 more seconds". But eventually we managed and I started taking things apart. Once the forks were all disassembled, I must say, boy its a miracle I am still alive. I am putting in progressive springs which you can see in the back on one of the pics, also new bushings and other bits and pieces. As well as the correct amount of oil and pre-load. More info on assembly will come later.

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      • #18

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        • #19
          While one person holds it level, another can use a jack under the motor to get the front in the air, then use jackstands on framesliders.
          '89 Hawk a.k.a. The RallyHawk (my son's now!) | '89 Hawk a.k.a. The Deuce | Spare Parts/Dented Learner Bike | '13 Tacoma | '69 Falcon (currently getting reassembled! )

          I've spent most of my money on women, beer, cars and motorcycles. The rest of it I just wasted.

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          • #20
            Nice job getting the forks apart! The damper rod bolts can often seize and resist even the persuasions of an impact gun and there's no easy way of holding the damper rods while you work this out. Fortune smiles.

            I've never seen Progressive brand springs before. They look progressive in name only.

            The major shortcoming with damper rod forks is, well, the damper rod which tries to provide damping across the entire range of fork travel speeds by forcing oil of a fixed viscosity through a hole(s) of a fixed size - obviously it will feel mushy over small or smooth bumps and harsh over large or sharp ones and there is no way around this. If you like the bike you will get fed up with the suspension as it is.
            Last edited by JB; 1 Week Ago.
            www.thermaecooling.com

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            • #21
              Originally Posted by JB View Post
              Nice job getting the forks apart! The damper rod bolts can often seize and resist even the persuasions of an impact gun and there's no easy way of holding the damper rods while you work this out. Fortune smiles.

              I've never seen Progressive brand springs before. They look progressive in name only.

              The major shortcoming with damper rod forks is, well, the damper rod which tries to provide damping across the entire range of fork travel speeds by forcing oil of a fixed viscosity through a hole(s) of a fixed size - obviously it will feel mushy over small or smooth bumps and harsh over large or sharp ones and there is no way around this. If you like the bike you will get fed up with the suspension as it is.
              Thank JB,

              But before we take off bashing on the progressive springs which I got from HAGON (a respectable MC springs and shocks provider). I would like to say that they are actually quite nice, and much stiffer than the originals. The ride is superb, but then again, I am not a racer of any kind so they serve well.
              As for the damper rod bolts, yeah, they were a bit stuck, and very much molested from the last "rebuild" attempt, which I was fortunately not a part of. Actually ended up putting a tiny drop of lock-tight on them, which I will surely regret in the future. Everything else went fairly smooth and the bike is back to daily service.

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              • #22
                I wasn't bashing Progressive, I was just observing their fork springs are not in fact progressive but 2 stage - once the tightly coiled section collapses on itself the spring rate changes immediately to the rate of the less tightly coiled section. In this respect they're much like the stock springs though as you said a heavier spring rate. A true progressive spring looks like this: progressive.jpgprogressive.jpg
                www.thermaecooling.com

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                • #23
                  Alright, hehe... Yeah, I suppose they dont look too progressive compared to the photos you posted. Although they behave wonderfully, especially with a heavier grade oil (15w).
                  There is however one thing that puzzled me during the rebuild. I have cleaned both fork tubes without leaving a drop of old oil behind. But when I poured the advised quantity of oil into them (503ml) , the oil level in one fork was higher than the other, even after pumping them to the full extension/collapse for 20-25 times. Where did I go wrong? The bike rides great, and I cant tell that one fork has a different level of oil in it. Before mounting them I also tried to compare the rate at which they compress, which also seemed to be identical.

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                  • #24
                    Others have experienced the same, for this reason it's much better to always go by oil level (measuring from the top of the fork tube with the forks compressed fully and the springs removed) than by volume.
                    www.thermaecooling.com

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