Are they Kyosho gold shocks or are they Duratrax?

Are these original Kyosho gold shocks, or are they the leaking Duratrax knock-offs? Answer is at the end of the article.

If you’re reading this blog, I’m sure you are aware of the ever returning discussions if the gold shocks are Kyoshos own Option House shocks, or if they are the notoriously leaking Duratrax copies. Well, if you’re paying attention while reading this, you already know how to tell them apart. If they leak badly, they’re “Duraleaks”, and if the’re holding the oil for decades, they’re Kyoshos! Oh, if only the world was that simple…. I have had Duratrax shocks that have kept the oil very well, even if the majority leaves a mess when used or when stored for a prolonged time. The Kyoshos are much more consistent in keeping the oil where it should be, and that’s inside the shocks! But bad O-rings etc. could make the Kyoshos leak as well, so amount of leakage is not enough to determine the origins of the shocks, but if the leakage is really bad, they’re probably Duratrax.

Numerous times I have seen Duratrax shocks put up for sale, both on eBay and in the various Facebook-groups, where they are presented as “Kyosho golds”. There could of course be various reasons for this, either the sellers don’t know they are Duratrax, or it could actually be that the seller do know their origin, but plays “dumb” in hope of getting a little more money for them. To end this “problem” once and for all, I have disassembled two short shocks, one Kyosho and one Duratrax, and compared the different parts. I have also made a check list that could be used to tell which is which, both from the outside and from the inside. I have ignored the plastic parts, like the spring retainers and clamps, as these are often changed on the Duratrax shocks, as the Duratrax plastic is very brittle, and breaks easily. Generally you can say that the Duratrax retainers are a tiny bit more shiny than the Kyosho plastic, and the Duratrax bottom retainers are flat while the Kyoshos are cone shaped. The flat shape is also a reason they break more easily, I believe.

So here’s the check list to tell them apart:

  1. Colour. Most of the Duratrax shocks have a brighter gold anodizing than the Kyoshos. There were however larger differences between the Duratrax shocks than between the Kyosho shocks. The anodizing could also fade with age or because of exposure to various things like light, chemicals etc. The conclusion is that if they are very bright gold, they are Duratrax, but if they are a lighter gold, they could be either.

    The shock at the top is a Duratrax, and the bottom one is a Kyosho. Notice the brighter colour of the former, and the difference in lenght.
  2. Length. I have only compared the short versions of the shocks, and the Kyoshos are actually quite a bit longer than the Duratrax shocks. Both the housing and the piston rod are longer on the Kyoshos.
  3. The top cap. The caps are also a bit different if you look closely, both on the outside, and on the inside. See the pictures, as those tell it better than I can do with words.
    Kyosho cap to the left, and Duratrax to the right. Notice how the U-shaped area goes all the way to the edge on the Duratrax.

    Again, Kyosho to the left and Duratrax to the right, but this time the insides of the caps.
  4. The housing. The Kyosho housings (at least on the short front shocks) are, as I said earlier, longer than the Duratrax housings. They also have a sharper edge at the bottom, compared to the more chamfered edge of the Duratrax. Again see the pictures.
    Duratrax on top and Kyosho at the bottom.

    Kyosho on the left and Duratrax to the right. Notice the more chamfered edge of the Duratrax, as opposed to the much sharper edge of the Kyosho.
  5. The bladder. The bladders inside the top caps are also different, with the Kyoshos having a flatter shape than the more pointed shape of the Duratrax.

    Kyosho bladder to the left, Duratrax to the right.
  6. The pistons and piston rods. As mentioned earlier, the Kyosho rods are a little longer than the Duratrax rods. The plastic pistons on the Kyoshos are red (this is only true for the older Kyosho golds as later batches have black plastic parts), while the Duratrax shocks have black pistons. A smart feature of the Duratrax pistons is that they are slotted, so a screwdriver can be used to screw the ball end on, after you have put the rod into the housing.

    Kyosho to the left, and Duratrax to the right. Notice how the Duratrax is slotted, for easier mounting of the ball end.
  7. The seals. The Kyosho shocks have an extra O-ring compared to the Duratrax. This is the main reason for the Duratrax leaks.

    Duratrax seals on top and Kyosho seals at the bottom. Notice the extra O-ring on the Kyosho.

So that’s it. Now you no longer have an excuse to list Duratrax shocks for sale as “Kyosho golds”!

PS. The shocks in the featured image are Duratrax. This can easily be seen by looking at the top caps where the U-shaped section goes all the way down to the edge.

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About TomEG 57 Articles
I have been into RC cars since the beginning of the 80's, but have really never been much of a racer. I competed in some local races and some "Tamiya Cups", and actually came 6th in the Tamiya Cup Norwegian Nationals in 1987. My main interest has always been building and modifying, and that's where I still am today. Through the years I have been able to build a solid network of contacts around the world, consisting of both former and current members of the industry, as well as quite a few of the former top drivers. I have a genuine interest for the history of the 1/10 scale off-road buggies from the 80's.

1 Comment

  1. Use a quality O-ring such as the Revolution Design Ultra O-rings (p/n RDRP2001), combined with a quality assembly lube such as Muchmore Racing Shock Slime, and you’ll never have a leaking Duratrax shock again (or any other brand shock for that matter). And if the shorter overall length is a bother, then use Yokomo shock ends (p/n YOKZ2-S6M) which include 3 lengths for fine tuning and are a direct fit.

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