Dura Ace Cable Coating, Teflon?
08-07-19, 10:25 PM
#1
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Dura Ace Cable Coating, Teflon?
I ordered these Dura Ace cables and the cables came coated in this dirty bronze coating (assuming this polymer is a teflon coating )
After running cables through and pulling them and running them through again (about thrice) trying to get cable housing lengths cut to where I want them and using a little bit of heat shrink I noticed the bronze coating started to fray. The bike I have is circa 2013 and has exposed cables on the downtube to the derailleurs. So seeing a fuzzy cable on the downtube is not cool. So I sanded the exposed area down to 600 grit and it was nice and shiny and smooth. It was much smoother than the rest of the cable so I just sanded the whole thing.
Lightly frayed... some sections were much worse than this.
120 grit sanded already looking way better.
Just curious what the coating is and why they use it. The old cables I pulled were coated in the same way and I believe the coating is what was gunked up in the outer casing when I pulled the old cables. Little chunks of it would come out each time a ran an old cable through it.
They are probably better suited to bikes that run cable housing all the way through the bike and not so much for exposed cables.
Thanks.
-Sean
PS- it was hard to get a good pic and the lighting makes the cables look dirty. But if you have worked with these cables before I am sure you know what I am talking about.
After running cables through and pulling them and running them through again (about thrice) trying to get cable housing lengths cut to where I want them and using a little bit of heat shrink I noticed the bronze coating started to fray. The bike I have is circa 2013 and has exposed cables on the downtube to the derailleurs. So seeing a fuzzy cable on the downtube is not cool. So I sanded the exposed area down to 600 grit and it was nice and shiny and smooth. It was much smoother than the rest of the cable so I just sanded the whole thing.
Lightly frayed... some sections were much worse than this.
120 grit sanded already looking way better.
Just curious what the coating is and why they use it. The old cables I pulled were coated in the same way and I believe the coating is what was gunked up in the outer casing when I pulled the old cables. Little chunks of it would come out each time a ran an old cable through it.
They are probably better suited to bikes that run cable housing all the way through the bike and not so much for exposed cables.
Thanks.
-Sean
PS- it was hard to get a good pic and the lighting makes the cables look dirty. But if you have worked with these cables before I am sure you know what I am talking about.
08-07-19, 10:34 PM
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When new and not frayed they are buttery smooth compared to oncoated or ptfe coated cables. I recommend not pulling them in and out of housing and ferrules unnecessarily next time now that you have the cable housing lengths dialed. They dont last as long but work the best out of the box
08-08-19, 05:21 AM
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This peeling (and difficulty in clamping them) is why I stick with un-coated, die-drawn inner wires with lined housings. The coating causes too many headaches for my taste.
08-08-19, 07:24 AM
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Don't think Shimano will give the makeup of their super duper secret polymer coating. To me they are a problematic solution to a problem I don't have. I do use SP41 but with stainless die drawn cables and am happy with shifting and cable/housing life. It make we wonder about the latest innovations in drivetrains, must be killer shifting for a non-racer to have to deal with short life cable/housing.
08-08-19, 08:17 AM
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Be sure to scrape off all of the coating where the cable clamps to the derailleur clamp bolt. Otherwise the cable is likely to slip over time and upset your shifting.
08-08-19, 08:36 AM
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Polytetrafluoroethylene (PTFE) of which Teflon(R) is one brand, has among the lowest coefficients of friction, but is much softer than other polymers.
I observed this fraying issue myself. I think the key is get the lengths dialed in, then carefully unwrap the cables and cut housing to length, then route the cable once.
I'm kind of surprised that the coating is not more durable. W.LGore makes GoreTex(R) coated guitar strings (GoreTex is essentially high molecular weight PTFE, stretched into sheets to create very small pores that gas such as water vapor will travel through, but that liquid will not due to surface tension considerations). These guitar strings hold up ok.
I observed this fraying issue myself. I think the key is get the lengths dialed in, then carefully unwrap the cables and cut housing to length, then route the cable once.
I'm kind of surprised that the coating is not more durable. W.LGore makes GoreTex(R) coated guitar strings (GoreTex is essentially high molecular weight PTFE, stretched into sheets to create very small pores that gas such as water vapor will travel through, but that liquid will not due to surface tension considerations). These guitar strings hold up ok.
