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Old 08-24-11, 03:02 PM   #1
TallRider
me have long head tube
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any downside to front brake cable (cantilever) hanging from stem?

I'm rebuilding an old bike with cantilever brakes. Instead of having a cable hanger hanging off the top of the headset, this bike has a cable stop drilled into the quill stem.
Similar to what is pictured here, except that the pictured link appears to be a DIY hack-job whereas the stem I have was designed with the drilled-in cable stop.

Aside from the fact that raising or lowering the stem will require re-adjusting the brakes, is there any downside to such a setup? I could put a more typical cable stop/hanger onto the top of the headset if that's preferable.
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Old 08-24-11, 03:25 PM   #2
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Tallrider: I prefer a fork mounted cable stop like this one: http://www.specialized.com/us/en/bc/...jsp?spid=47409 It eliminates the brake chatter which sometimes arises from the flexing of the steerer under braking with stem- or headset-mounted hangers . There have been several discussions regarding this effect on this forum. This particular model has a built-in barrel adjuster which is convenient especially if your brake levers lack one. I put them on all of my canti-equipped bikes.
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Old 08-24-11, 08:21 PM   #3
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Thanks. I'd heard of the upper vs. lower issue before (and I suppose I'm particularly susceptible, being tall and having really long head tubes/steerer tubes and all). So at least that says there's likely not much difference between running the brake cable from the quill stem vs. from a hanger on the upper headset race. I may install one of the lower-mounted hangers later if I have chatter issues.
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Old 08-24-11, 08:27 PM   #4
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This thread just yesterday was talking about.
I bought both the Specialized and Tektro units.
I ended up using the Tektro and drilled it out myself to accept a barrel adjuster.

http://www.bikeforums.net/showthread...on-carbon-fork
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Old 08-24-11, 09:29 PM   #5
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Whether hanging the cable from the stem creates problems or not really depend on the fork and brakes.

This was a common practice for decades without folks having issues, but as steel forks gave way to less rigid carbon forks, and with brakes and mounting bosses also less rigid more people are having problems with arrangement causing modulation problems.
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Old 08-24-11, 10:11 PM   #6
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but as steel forks gave way to less rigid carbon forks, and with brakes and mounting bosses also less rigid more people are having problems with arrangement causing modulation problems.
Your logic makes sense, but I thought the old steel forks were less rigid? I've ridden some older bikes where hammering the front brake makes the fork dive back. I thought they eliminated this (because people were scared of seeing their forks bend?) with the newer forks by making them stiffer.
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Old 08-24-11, 10:24 PM   #7
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Your logic makes sense, but I thought the old steel forks were less rigid? I've ridden some older bikes where hammering the front brake makes the fork dive back. I thought they eliminated this (because people were scared of seeing their forks bend?) with the newer forks by making them stiffer.
It's not a matter of total rigidity, but the nature of flex. Steel forks tend to flex in the blades, where it doesn't affect braking. They're very rigid from the upper blades, through the crown and steerer.

Also the tops of the steel blades where the bosses are attached are very stiff. If you look at an older high quality steel fork with canti's you'll see less outward movement of the bosses when brakes are applied compared to many newer forks.

Then there's the effect of threadless headsets and stems mounted above multiple spacers, compared to threaded headsets with quill stems that buttress the steerer deep below the upper bearing.

Obviously you can't translate the general to specific bikes, so you have to deal with each bike as it actually is.

My commuter has an alloy fork, quill stem and locknut mounted brake hanger, and has zero modulation issues. I see others with similarly built forks, but with threadless headsets, and they have issues.

I believe the problem has multiple causes which work in combination, and while one or two might not cause shuddering, multiple ones will.
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Old 08-25-11, 12:57 AM   #8
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stiff old, frame, not much of an issue,light springy frame, like my AlAn Cross Super,
drilling a hole in the stem, for the front derailleur ,
looked clean, but the front end cable in tension versus the frame and fork flexing,
created a resonance.
that scared you when you,in dry conditions, grabbed the front brakes .
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