Update: It's fixed. More info in the comments.

I searched and couldn’t find any general bicycle forums here on Lemmy. This one seemed to be the closest match out of the three I found. So I hope it’s okay to ask for help here.

I have the exact same problem as in this video:

https://youtu.be/aP-N6D7NKtc

But the solution he presents does not work for me. All of the videos on YT about sidepull brakes have the same general solution and none of them work.

I center. I tighten. Etc. And when I pull the handle, the cable yanks the whole caliper sideways and I’m right back where I started.

I used to work on my cars when I owned them. I can fix my computer. My sink. My toilet. Everything on my bike except the brakes. They make no sense to me.

The anchor and the pivot of sidepull brakes are the same. So the fact that the caliper is being yanked to one side makes sense. The functional brakes I see don’t make sense. How do these things work?

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[–] 2 points 4 days ago (14 children)

Video is unavailable for me.

There is also !bikewrench@lemmy.world

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  • [–] 2 points 4 days ago* (11 children)

    I am guessing they are like this?

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  • [–] [S] 1 point 4 days ago (10 children)

    They're just like that.

    The video isn't coming up for you guys?

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  • [–] 2 points 4 days ago* (last edited 4 days ago) (9 children)

    When you tighten them can you still freely open and close the arms? Can you manually actuate the brakes by pressing c& d (on my image) towards your rim?

    Ideally when you press your brake handle the cable should pull A up, pushing C against the rim, which causes B to go down pressing D against the rim.

    Edit: I had directions backwards

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  • [–] [S] 1 point 4 days ago (8 children)

    By hand, yes. I took them off completely last night and I can squeeze them like a hand gripper exercise.

    When I press the brake handle, A goes up and pulls C to the rim, and I guess B goes down and pushes D against the rim. But when I release. D stays against the rim.

    It seems like when B goes down it twists the whole assembly around to the left.

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  • [–] 1 point 4 days ago (3 children)

    The nut at the back of the fork is what should be holding the assembly in place. Maybe try making that nut tighter?

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  • [–] [S] 1 point 3 days ago (2 children)

    Forgetting my bike and looking at the photo, the paradox is that B is supposed to push D around the center bolt but at the same time, not allow that to happen. I can't wrap my mind around how this mechanism is suppose to work. It shouldn't.

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  • [–] 1 point 3 days ago (1 child)

    The mechanism works because the "head" of the bolt is in the middle. It's a double ended bolt basically. The nut on the end that goes into the bike only attaches it to the bike, and it's tightness has no impact on the functioning of the brake, other than stopping the bolt rotating.

    There are 2 nuts at the other end. The inner one needs to be loose, to allow the brake leavers to rotate freely, and the outer one is tightened against the loose one to keep it in place.

    I'll try making a diagram when I get home.

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  • [–] [S] 1 point 3 days ago

    I think I finally figured it out. I took the whole thing apart, examined it, and re-assembled it.

    It seems to all hinge on the notches the spring slides in to. If the notches aren't lined up and/or the spring slips out of the notches when the brake is pulled, the brakes get stuck.

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  • [–] 2 points 4 days ago (3 children)

    There should be a spring inside between AC and BD so that when you release the brake handle it opens up again. If that is not happening you may need to separate the two and replace the spring, or maybe there are notches so you can increase the tension.

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  • [–] [S] 1 point 4 days ago (2 children)

    The spring is there and working. The problem is that, if we call the center pivot bolt E, when B pushes down on D, A C & D roll around E.

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  • [–] 2 points 4 days ago (1 child)

    Without seeing anything, it sounds like something is wrong with E.

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  • [–] [S] 1 point 3 days ago

    The problem is that physics dictates that the whole assembly is supposed to rotate around E. But functional brakes use some kind of unexplainable magic to keep it from rotating around E.

    I ended up taking the whole thing apart yesterday so I can spray it all with WD40. I took the spring out and I don't think I can get it back in, so I think I'm just going to duct tape what's left to the handle bars and go with one brake for a while.

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  • [–] [S] 1 point 4 days ago (1 child)

    That's weird it's not coming up. Every video on fixing side-pull brakes are pretty much the same but this is the name of the video I linked to "Adjust / Center Side Pull Caliper Brakes That Are Hitting Rim Uneven" by Ivans Bikes Bmws.

    My bike is an Outroad Road Bike 700C Commuter Bicycle

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