Tech talk: Kashima Coat

Is Kashima Coat worth it? In this tech talk, I will try to answer this question in a logical and reasonable way, with an emphasis on science over emotional and subjective beliefs.



Kashima Coat is found on Fox products and the new Yeti Switch Infinity rails, usually on surfaces that slide against each other. The primary controversy that pops up about it is about whether or not the coating makes it so there's noticeably less friction. Whether you can notice it or not is subjective, but if it does lower friction, this effect would be most notable if the friction were noticeably high in the first place. A 40 or 36mm fork stanchion, sliding against a dust wiper, oil seal and bushings with more surface area in contact would have more friction than a 34 and 32mm stanchion, a typical Fox Float rear shock, and a Fox RC4 coil shock's shaft. The controversy seems to divert peoples' attention away from the primary claim, increased wear resistance. Perhaps this claim was reinterpreted and then confused with increase durability, toughness, or lower friction, when wear resistance is quite specific.



What is Kashima Coat?
Kashima Coat is a proprietary hard anodizing process developed by Miyaki Corp. in which they take advantage of the properties of an anodized film, which is basically aluminum (II) oxide, and uses electrical induction to fill the pores with molybdenum disulphide (MoS2). It offers increased wear resistance and increase corrosion resistance (and heat resistance and electrical insulation). The charts specify that in a sliding or piston action without lubrication, it has a coefficient of friction of 0.17 vs 0.20 for a basic hard ano coat. It is claimed to have 3x the hardness of chrome plating, but this claim is hard to interpret, as chrome plating hardness varies due to thickness (decorative vs hard chrome) and it's hard to believe it's 3x harder than hard chrome, as chromium is almost as hard as a diamond. Its color changes from a light/bright gold to a darker brown color as the coating's thickness increases.

Why use it on aluminum sliders?
For me to better understand this, I figured I must first better understand aluminum. Aluminum is sometimes considered to be a post-transition metal and a main-group metal on the periodic table. It is considered a relatively soft metal, with a relatively low Moh's hardness (3.0). Its relatively low mechanical strength issue must be addressed to a satisfactory level for the products' intended use. When alloyed with other metals, it can have much stronger mechanical strength while retaining low density, and ductility, along with other properties which make it easy to work with, such as low melting point. It can be charged to create an uniform layer of oxidization, Al2O2 or Al3O2 AKA aluminum (III) oxide, which is what makes up the anodized layer (the anode electrode of an electrical circuit). This layer increases corrosion resistance, but does not make the aluminum itself stronger. It is highly porous and thinner layers are susceptible to fractures, which may act as stress risers that cause the underlying aluminum to crack.

Many current fork products have stanchions which have dyes filling the pores of the anodized surface. The popular RockShox Pike simply has black dye, which has no advantage other than aesthetic value. Anodizing procedures are classified by how thick of a layer they produce. "Hard Anodizing", also known as Type III anodizing, creates a much thicker coat than Type II, which is the most prevalent kind of anodizing. Type III is much more costly, due to requiring more precise manufacturing methods, and is the process on which Kashima Coat is based on. It has deep pores for the MoS2 to be deposited into, but also has excellent wear resistance and lower risk of microfracture. MoS2 has characteristics compared to graphene, in terms of mechanical strength, on top of its dry lubrication value. By using a super-material such as MoS2 instead of dye to fill the pores, on top of a hard ano coat, the Kashima Coat has a lot going for it, on paper at least.

What does all this mean?
Fear not if you could not comprehend the "science lesson". In layman's terms, Kashima Coat offers negligible difference in friction. A lubricated nickel plated stanchion can have a coefficient of friction as low as 0.12, compared to the 0.17 of non-lubricated Kashima Coat (Teflon is 0.04). For reference, non-lubricated bare aluminum on bare aluminum is 1.0. It does not strengthen aluminum, so if it gets hit by something hard, that Kashima Coat is not just going to magically let it slide or deflect harmless off, instead of denting the aluminum. Compared to a dye, it will likely survive without lubrication much longer. Without testing, it is questionable as to whether or not it will stand up better to impacts such as chipping and scraping from rocks, shrubs, branches, hail, etc., but if its hardness claims play a role against such forces, it should stand up very well and there's little evidence of damage to Kashima Coated fork stanchions, based on a quick google image search. Its other benefits of corrosion resistance, electrical insulation, and heat resistance likely will only come into play in those freak occasions in which the rest of the bike is likely going to be ruined, riding your bike in storms and letting it get swept away by river you thought you could ford, or taking a boat across the water and losing it overboard, running into a burning house and riding out with your prized bike, getting splashed with lava on the way out, etc. :lol:

So is it worth getting Kashima Coat?
It definitely has some value, so it's not completely worthless. In general, I believe it is safe to say that it is not worth it on rear shocks, since they generally have low amounts of friction and negligible durability concerns. On forks, I'd say they are worth it if you keep your fork for at least 2 years, or ride it a lot, especially in harsh conditions. The coating is insurance for riders who neglect to do regular service. If you take meticulous care of your fork, it is just a fancy looking dye. On the other hand, you can take it as a ticket to safely extend your service intervals over the conservative Fox intervals (in which Fox assumes that you ride through the worst slop imaginable). If you pay $40 for service after before and after summer each time, the coating may pay for itself if you switch to an annual service, and look blinging. Forks are very expensive and it surprises me as a mechanic, how reluctant people are to spend money on maintenance, when it costs far less than a replacement. Bottom line, if you're not the meticulous type that services their stuff regularly, it is an upgrade well worth the asking price for Fox forks. If it comes on anything else as standard, you can just view it as extra peace of mind regarding wear resistance. If you are buying a Kashima coated product, and have the opportunity to look at the stock side by side, choose the darker colored one as it has a thicker coat.

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Comments, questions, suggestions?

Did this article clear up any misunderstandings about Kashima Coat? Did I happen to sell anyone on Kashima Coat? Are any Kashima Coat product owners more confident about their product now? Anyone suffering from buyer's remorse? Did I remind anyone to service their forks? Wondering why the air can on rear shocks is also kashima coated?

Thanks for reading. Until next time, I'll be looking for an interesting topic to tackle, better understand, and clear up the misconceptions and controversy.

 

Actually this article made me glad I have the Kashima Coat on my forks and shock. Originally I thought it was for buttery smooth performance but as well, finding out it has an excellent protectant quality from the elements gives me the piece of mind that it still has some value. I really like how my fork performs...

...Thanks for taking the time to dig in to the facts and sharing your results!

~Mikie

 

Just a FYI, while lubricated nickel coating is actually pretty slick, non-lubricated nickel actually has a pretty high coefficient of friction of around 0.50 to 0.78 depending on the other sliding surface. It suffers from not only friction, but also adhesion. Think of the "sticky rubbing sounds" of skin sliding on freshly cleaned glass or a plated playground slide after a rain, and that will give you an idea of adhesion. Since there's less pores, there's more surface area in contact and less area for lubrication to stick to. I'm not surprised to see Marzocchi dropping their nickel coated design.

Fox's buttery smooth action claims is likely just their marketing. When they introduced Kashima Coat, they also changed to SKF seals with a lower friction design. It's not false advertising, as their definition of buttery smooth may differ from a customers and it's the customer's imagination that is creating the false info. In the MX industry and other offroad vehicles, it's actually desirable, and some are willing to pay $500 to have their suspension parts sent off by suspension tuners to get it ($700 for Diamond-like coating).

 

Not sure about Kashima but Push sold me on their upgrade and "conversion" for my RP23 and I'm waiting to receive the service, custom-tuned, upgraded shock. Will share my review after it's installed and I take it her for a ride. $280 vs. $450+ for a new one was a no-brainer for me.

 

Sounds like the same as people who prefer nickel boron coating on their BCG (bolt carrier group - AR rifles). I just ordered a Keltec SUB2000 (firearm) with the Nickel Boron Nitride coating on the BCG. Does it work? Well, the more you use it, yes..it's worth it to have. I call it slippery metal.

 

Nice analogy. That coating seems more useful for steel, while Kashima coat is more for aluminum, due to how the anodizing process works and how the nano particles of MoS2 are deposited. Similar properties, but pitched/marketed a bit differently. That coating of yours seems to release deposits easier as well, for easier cleaning. The question is similar to the one asked here, how much does the upgrade cost over a less expensive option, and is it worth it? You'd likely end up with similar dependencies to answer that: Do you meticulously clean and lube your gun after each session? Do you wear out your parts often? Do you have sessions that generate a lot of heat quickly (full auto), or are in an environment that gets the gun dirty, that may cause issues?

 

Yeah, I still clean/lube after each time out (both long and pistols)..just overall good housekeeping..it may even be more so important for suspension as I doubt anyone "rarely" pulls it apart after each ride? I usually shoot in Prado or ASR, so, yeah..dusty.

 

Kashima is anodizing. I did a cursory search for coefficients of friction, and regular anodizing can be found to have as less than, as much as and more than Kashima. My take, it's branded and therefore is a known quantity. Can't say the same for anything else out there. Personally, I'd go with a Pike despite Kashima

 

Stating that "Kashima" is anodizing, is like saying the F-35 is a plane. Following up with cursory search like that, is like comparing the listed top speed of the F-35 with an obsolete and cancelled project like X-30, and coming to the conclusion that the F-35 is "branded" and not superior to other planes. While those statements aren't totally false, you are missing much of the whole picture, which would allow you to completely understand how attractive such a design is at fulfilling an intended role.

To give you a digest version, Kashima Coat process is a hard ano, which is a thicker and stronger anodization than a typical "decorative" anodized coat. The process involves filling the pores with a super material called molybdenum disulphide, which is comparable to graphene in strength (related to carbon nano tubes), but with dry lubrication properties (not unlike graphite). The main reason why this super material isn't being used for other things, is because that it's hard to create things with it, but the Kashima process is an innovative process that is able to take advantage of it. The Pike fills the pores with black dye, but they're not fully filled. The pores on the Pike's stanchion allow the bath oil to better cling to it. The anodizing process creates such pores, so they're not unique to the Pike. A super smooth and polished surface would have trouble holding its lubrication. The Kashima Coated stanchion will last a long time even without lubrication, while the Pike stanchion won't. Oddly enough, the RockShox puts in way less bath oil (15 mL NDS/5 mL DS) than Fox in the lower legs (usually 30 mL each leg for Float FIT forks), probably in the name of weight savings. RockShox recently ventured with a "Diamond-like carbon" coating, which had an interesting effect that when bath oil was absorbed into its pores, it would have an "oil slick" look. It was apparently very expensive to implement. It was often asked if the Pike's black stanchions were DLC, but RockShox admitted that the black was purely cosmetic.

There were many previous attempts at finding a super slippery coating, from TiNitride, to Silver, but they proved to not been very long wearing. Kashima Coat is the only one that seems to have proven itself, though it's more for its long wearing properties than its slickness. I would presume that it reduces wear to bushings as well. In the MX world, tuners charge ~$500 to have customers' stanchions Kashima coated.

At least with black stanchions, it'll be easier to see the wear due to neglect:

 

The F35 is a plane You wanna drink from that trough, go for it. TiNi doesnt stick to alu all that good, that's why it's not used. There are a few kinds of hard anodizing, Kashimi is just one of them. Servicing forks, the only time anodizing wears out is from negligence from the owner. Change the oil on a regular basis and it's all good.

 

Hey Dan,
Just wanted you to know I finally published this article over on the Mag for you. Thanks Man! Great Article! :clap:

Here: <a class="postlink" href="http://imtbtrails.com/magazine/?p=1101" onclick="window.open(this.href);return false;">http://imtbtrails.com/magazine/?p=1101</a>

~Mikie

 

I did my own extremely scientific survey of Kashima in 2012. I bought the top of the line Fox 36 TALAS Kashima FIT RLC. It sucked balls. I had it professionally rebuilt. It still sucked balls. I sent it to Fox, they "fixed" it and it still sucked balls. What sucked about it? There was no usable air spring setting. At 55psi, it dove at the slightest provocation, dangerously so. At 58psi, I used about half of the travel and it was harsh. No other settings or adjustments helped to correct this.

So I bought a Marzocchi 55 Micro Switch TA. Plush right out of the box. Mid-stroke support. Gentle bottom out. Adjustments worked. And plush. Stiff chassis for great front end control (the Fox chassis was great too). Did I mention that the Marz was plush on little trail chatter?

So my experiment ended in this fashion. Who gives a sh** about Kashima if the fork blows. Kashima looks cool, so if that matters to you, go for it.

Oh, I almost forgot. I have a Fox CTD shock with Kashima. It was meh until I had it custom rebuilt by Avalanche. Now it's friggin' awesome. Nothing to do with Kashima.

Epilogue: In the interest of full disclosure, I did have some problems with my Marz that had to be fixed by the factory (for free). After about 40 hours, it began stiffening up to the point where I had to use less and less air to get the same amount of travel. Eventually, the ride became harsh, or I had brake dive from too low of pressure. A regular service did not correct the problem. Marzocchi fixed it with new internals. For free. Overnight (I dropped it off and picked it up).

 

Just discovering the Tech Talk series... this is good interneting!