Varaxis
Well-Known Member
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.
====================
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.
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.
====================
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.
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.
