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Discussion Starter · #1 ·
Please help an old man and an old bike in their twilight years.
I just did a major overhaul. New brakes, chain, cassette, cable and housing. New bearing in hubs, etc. The bike is about 25 years old. My last problem is the alignment of the brakes. It was always necessary to have one post pushed far in and other far out. As can be seen from the image, the brake cable coming out of the hanger is not centered. This was the best I could do get the brake to have clearance on by sides.
This bike and me has been through a lot together. Has seen friends come and go.
Any ideas will be appreciated. Could it be a frame alignment problem?

Thanks in advance
 

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First, check the backside of the cantilever mounts. You may see the brazed on fitting where the spring connects. Most of the time that fitting will offer you the choice of 3 different hole positions. Changing the position the spring mounts into the hole changes the amount of spring tension on the arm. Wide differences between the left and right side will cause the problem in the photo.

Start by ensuring both springs use the same hole position. Make the tension adjustment screws ( I see one on the non-drive side mount, you may have one on both sides) equal in thread engagement, then tweak them as needed to center the brake. If you only have one screw, then set it mid-thread and adjust as needed.

If that doesn't work, those yoke cables come in various pre-fab lengths. I think you have the wrong length and the housing half is too long. No; you can't cut the housing half and fix it as the bare wire section must be equal. Your local bike shop should have the other lengths. Bring yours with you as a sample.
 

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The brake pad posts must be protrude from their mounting eyelets by equal lengths. You adjusted them wrong. There should also be a spring tension screw in one or both brake arms to help center the brakes


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Discussion Starter · #4 ·
Both springs are in the middle hole. The spring tension screw will only move it a small amount.
 

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Discussion Starter · #6 ·
Is one spring in backwards?

No

I should also say that this is my third set of brakes in the 25 plus years that I have had the bike and this has been an on going problem.
 

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In this case, don't place both springs in the same hole. Install so the drive side has stronger spring action than the non-drive side, then use the screw to fine-tune. If that doesn't work and each spring feels like they're apply equal spring action to their respective arm, then you've got to try a differently dimensioned yoke cable. Sheldon Brown's web site shows the various lengths available.
 

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Both springs are in the middle hole. The spring tension screw will only move it a small amount.
Change the hole that the spring is using on one or both sides until the levers are equal. The mounts may be installed off center and the different holes are there to give you the ability to center things up.
 

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Discussion Starter · #10 ·
I would like to determine whether the problem is with the alignment of the frame. I have no idea how to do this however. Any ideas will be appreciated.
 

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PeterP and Velodog have jointly suggested a probable solution. Try that and report. I'm at a loss in understanding how frame alignment could be related.
 

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I would like to determine whether the problem is with the alignment of the frame. I have no idea how to do this however. Any ideas will be appreciated.
I'd be hard pressed to see how the frame would have anything to do with it, it's probably the alignment of the brake mounting bosses to the front fork, measure that. In fact it might be that one or both of the rings for the spring has been brazed on wonkie. You can see in this pic that the boss started life as separate pieces and had to be assembled on the bike.

This is where I'd be looking, and this is also why there are three holes there, to adjust the alignment of the brakes.

View attachment 314190
 

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As mfdemicco noted, one of your posts is protruding more than the other, by what looks to be close to a centimeter. Each side should be set up symmetrical to the other side in all respects. Then fine tune the spring tension with the screw adjustment, and major spring tension adjustment with the holes as others have noted.

Also, with the straddle cable, there is a 'locked' position where your cable goes into the straddle unit (I guess the yoke) and thru the bit of housing. It looks like yours is not set. Pull the cable over the notch in the yoke to fix the cable to the straddle cable.

Frame alignment isn't the problem. However, on a lot of low to mid range bikes, you'd be surprised how 'off' the cantilever bosses are welded to the fork (i.e, one higher or lower than the other).
 

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I would like to determine whether the problem is with the alignment of the frame. I have no idea how to do this however. Any ideas will be appreciated.
If you think your fork is bent (it wouldn't be a frame alignment issue but it could be a bent/twisted fork) simply flip the front wheel and check the distance from the fork blade to the rim. If the distance is the same regardless of which way the wheel is in the fork, then it is very unlikely the fork is the issue. And as a double-check, try this with someone else's wheel, just in case your front wheel was accidentally dished during a botched truing or building incident.
 
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