Dura Ace brake cable ferrules?
londoncommuter
Posts: 1,550
I've a bit of a problem with a frame in that the hole for the rear brake cable to enter the top tube won't accommodate a ferrule. I'm using Dura Ace 9000 Polymer coated cables.
How important is this?
The frame manufacturer says there's no need for brake ferrules as the internal cable stops do this.
The issue I have is, using the cabling moved over from the first frame (this is a warranty replacement) there seems to be a tiny bit of drag in the system somewhere as I can pull the lever a tiny tiny fraction of a millimeter and hear the cable moving somewhere in the tube before the brakes move. It's nothing to do with the caliper not being strong enough to fully pull the cable back as it's as springy as the day it came out of the shop.
Struggling to see what difference a ferrule could make but I must be missing something obvious.
Any suggestions or tips very gratefully received.
On the same sort of thing, does that Shimano diagram make sense? Which end(s) do they say you should use ferrules with noses?
How important is this?
The frame manufacturer says there's no need for brake ferrules as the internal cable stops do this.
The issue I have is, using the cabling moved over from the first frame (this is a warranty replacement) there seems to be a tiny bit of drag in the system somewhere as I can pull the lever a tiny tiny fraction of a millimeter and hear the cable moving somewhere in the tube before the brakes move. It's nothing to do with the caliper not being strong enough to fully pull the cable back as it's as springy as the day it came out of the shop.
Struggling to see what difference a ferrule could make but I must be missing something obvious.
Any suggestions or tips very gratefully received.
On the same sort of thing, does that Shimano diagram make sense? Which end(s) do they say you should use ferrules with noses?
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Comments
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The Shimano diagram shows that if using the ferrules, the ones with tongues go at both positions marked 'A', so where the cables exit frame.
Whther or not to use ferrules depends on the frame grommets, my Colnago's grommets are wide hence the internal gear cables need ferrules where they enter the downtube (the rear brake is not internally routed. On both my Scotts (Foil and Solace) no ferrules are required as the grommets for the rear brake and gear cables are designed to accept the bare outers.
May be an idea to check you have a very clean cut on your outers and that the cross section is perfectly round as anything which causes the outer to not sit flush in the grommet could cause cable drag.Scott Foil RC
Scott Addict RC
Trek Emonda0 -
Yea no need for ferrules but make sure the outers are cut square. i usually file the ends down so that they are flat and perpendicular to the cable axis.FFS! Harden up and grow a pair
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Many thanks.
My slight confusion is that, as the cable stops are internal, I can't see what they're like. If they were malformed in some way they'd let the cable outer shift?
As I mentioned, my first frame took ferrules front and back but the replacement won't take one at the front. Worries me there is a problem with the frame but I can't face arguing with the manufacturer especially as it's tricky to work out exactly what the issue is.
Here are photos of the two holes, you can see a ferrule pops into the rear no problem but not the front:
Entry:
Exit:
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