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  1. #1
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    Tungsten carbide for braking surface?

    I was watching a documentary on metals, and it said that tungsten carbide is the hardest metal on earth. It is both hard and strong, so it is virtually indestructible. Tank armors are made out of this.

    So it got me wonder. Why has any company make wheels with tungsten braking surface? This will assure that the braking surface will outlast our lifetime, no?

    Or better yet, why are there tungsten carbide wheels and frames?

  2. #2
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    Ceramic is pretty much just as hard and I'm guessing easier/cheaper to form so why bother if ultimate hardness is what's wanted.

    Many builder don't work with stainless steel because it destroys tools. And many customers don't buy it because they don't see any advantage for the cost over what regular steel or ti. That probably goes more so for tungsten if it's even harder.

  3. #3
    Russian Troll Farmer
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    Well, for one thing, it's heavy. Also, steel of ANY type works extremely poorly in the wet. Also, carbide steels are brittle; make them thin, hit a pothole, and CRACK, it's new rim time. It's also EXTREMELY hard to machine; you'd have to spend an hour or more on an industrial grinder to make a smooth braking surface.
    "L'enfer, c'est les autres"

  4. #4
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    Quote Originally Posted by No Time Toulouse View Post
    Well, for one thing, it's heavy. Also, steel of ANY type works extremely poorly in the wet. Also, carbide steels are brittle; make them thin, hit a pothole, and CRACK, it's new rim time. It's also EXTREMELY hard to machine; you'd have to spend an hour or more on an industrial grinder to make a smooth braking surface.
    Other than that, it sounds great!

  5. #5
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    Rigida/Ryde use(d) tungsten carbide on the brake surfaces of their CSS rims.

  6. #6
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    Tungsten carbide for braking surface?

    I wonder what the coefficient of friction is with tungsten carbide and how it compares to aluminum. In my opinion, any of these thin coatings eventually wear off, as does anodizing on rims which is pretty hard also.

  7. #7
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    Quote Originally Posted by mfdemicco View Post
    I wonder what the coefficient of friction is with tungsten carbide and how it compares to aluminum. In my opinion, any of these thin coatings eventually wear off, as does anodizing on rims which is pretty hard also.
    For what it worth; braking with anodized rims is excellent. No point in buying anodized rims for that reason though because it'll wear off then you just have a regular alloy rim in the end. It last quite a while if you keep the pads clean but it's gone really quick if you ride in the rain. This is per my experience with H plus son Archetype. Great rim but I could take or leave the anodization because it's temporary.

  8. #8
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    The fact that aluminum is a bit soft is part of the reason alloy rims brake as well as they do. "Stiction". Putting a super hard coating over an alloy rim would be like going back to chromed steel rims.

    Generally, wheels are very well worn in many other ways before the brake track is worn through. The brake pad is the sacrificial part.
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  9. #9
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    I have a set of ceramic Open Sup rims from about 20 years ago with the ceramic coating still in perfect condition. Same with a slightly younger set of Open Pros. I only use these for commuting so they've seen some surprisingly foul weather. Braking on both sets is still excellent and predictable with the Shimano pads for ceramic rims. It wasn't until Mavic changed their process due to environmental legislation that quality went down and they eventually ceased production.

    I've seen some older Rigida ZAC rims and the CSS layer looked and felt different from actual ceramic coatings. Grey-ish and ever so slightly gritty like a very fine Emory board.

  10. #10
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    Quote Originally Posted by aclinjury View Post
    I was watching a documentary on metals, and it said that tungsten carbide is the hardest metal on earth. It is both hard and strong, so it is virtually indestructible. Tank armors are made out of this.
    Quote Originally Posted by Jay Strongbow View Post
    Ceramic is pretty much just as hard
    Tanks armors are combination of steel, ceramic, air gap and some other materials. The details are classified for obvious reason.

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