Motorcyle Fork Low Friction/Wear Surface
Motorcyle Fork Low Friction/Wear Surface
(OP)
Hoping for an explanation as to the advantages of low friction/wear surfaces on motorcycle fork legs. Current basic designs have PTFE coated bushes working with either hard chromed steel or aluminum in an oil environment.
Claims are made for significant improvement in wear and friction performance for the aluminum components by hard anodizing, and similar improvements to the steel components by substituting other coating for the chrome layer, eg TiN or DLC.
Given the low friction/wear properties of PTFE and hard chrome, why would there be any improvement to be gained by the changes to the alternative surface treatments as listed above.
Claims are made for significant improvement in wear and friction performance for the aluminum components by hard anodizing, and similar improvements to the steel components by substituting other coating for the chrome layer, eg TiN or DLC.
Given the low friction/wear properties of PTFE and hard chrome, why would there be any improvement to be gained by the changes to the alternative surface treatments as listed above.





RE: Motorcyle Fork Low Friction/Wear Surface
William Gunnar Naschak
http://www.IndustrialCoatingsWorld.com
http://www.nationalsurfacesolutions.com
RE: Motorcyle Fork Low Friction/Wear Surface
Again, is hard chrome coated with DLC or TiN that much superior to simple hard chrome in terms of friction, when rubbing against PTFE coated bushes.
Are the claims being made for these surface treatments worth the cost or just sales hype.
RE: Motorcyle Fork Low Friction/Wear Surface
Here, I'll try to answer your questions. First, the harder the base material (i.e. resistance to plastic deformation) the more effective the lubrication. Second, wear life will increase by coating the aluminum with hard anodize with Teflon seal, though friction, comparatively speaking, will increase. You will have to determine which is more important: lower friction or better wear-life.
The same rules apply (slightly higher friction vs. longer wear-life) when considering other forms of dry lubrication, such as the diamond-like coatings. Chrome and TiN are so close in hardness, I can't imagine combining the two, or giving up chrome, unless you're looking at it from an environmental, heavy metal standpoint: Cr(VI).
In short, surface treatments you've described, with a PTFE counter-face, can be excellent ways to extend the life of a "system". Whether that includes motorcycle forks is something I can't answer. Though I think you have, already.
Hope this helps. Best wishes.
William Gunnar Naschak
http://www.IndustrialCoatingsWorld.com
http://www.nationalsurfacesolutions.com
RE: Motorcyle Fork Low Friction/Wear Surface
This would support my suspicion that the "significant friction and wear advantages" claimed by various sections of the motorcycle industry for these expensive surface treatments is not justified.
RE: Motorcyle Fork Low Friction/Wear Surface
William Gunnar Naschak
http://www.IndustrialCoatingsWorld.com
http://www.nationalsurfacesolutions.com
RE: Motorcyle Fork Low Friction/Wear Surface
Most people have the coating applied during a fork rebuild that would usually include bush replacement, which might have a more significant affect of the friction performance. Interesting also that there have been reported instances where the OEM hard anodizing has had to be replaced due to failure, which raises the question as to the quality of the OEM anodizing and perhaps even its value in this application.
My own limited understanding of the friction/wear properties of stell/aluminium rubbing against PTFE coated bushes has made me skeptical of the unsubstantiated claims, hence my questions.