Gosh

I’ve been struggling with keeping the arms/pads from rubbing on one side of my rear brakes Shimano 105 caliper brake. When depressing/letting off the break the non spring side /drive side (other side from cable attachment) doesn’t open sufficiently to take up all the cable slack. The arm opens when I push down on the end. Please see video attached. I have just changed the housing and cable, thinking that might be the problem and the housing end are fully inserted into lever and ferrules, there are no burrs on the housings. It is though the cable housing isn’t springing back all take up all the cable. I would be grateful for some suggestions of how to fix or what I’ve been doing wrong. Thanks

Gosh

Sorry I’m having a problem uploading the video in the correct format as it doesn’t like video from iPhone. Here’s a still and I can seem to lose about the 10mm of movement.

Gosh

Can’t seem to lose

Iride01 

Why don't you just put the video on some hosting site such as youtube and just post the link to it.

However I'm having a time trying to understand your issue. But I might can imagine that you don't have the caliper and pads spaced equally on both sides of the rim. There is a small screw that determines how far on arm of the caliper will be from the rim. Then once they are equal, you just adjust the barrel adjuster or the position of the cable in the pinch bolt to get both at the correct distance from the rim.

Are you installing this brake? Or changing the cable? Or what is the history of this and when did it become an issue?

Page 13 of this pdf shows where the centering adjustment screw is for many of the Shimano series. However yours might be different. They don't look like my 105 brakes from the 5800 series. But maybe it's just the angle of the camera.
https://si.shimano.com/en/pdfs/dm/BR...003-09-ENG.pdf

HillRider

That "centering screw" is not needed for dual pivot brakes. Assuming the pivots aren't dirty or binding, all you do is adjust the cable length to get a proper pad separation, center the caliper over the rim by hand and snug down the mounting bolt. If one arm is binding check it's mounting bolt to the caliper and/or lubricate the pivot.

Trakhak

You'll be able to add a video now, since you're over the Bike Forums 10-post minimum for new posters.

The last time I had that problem with a brake: it turned out that I'd cut the cable housing just a bit too short.

Iride01 

I had to use it for mine and for the BR-4700 brakes on my son's bike. Perhaps you had direct mount brakes and/or everything was perfect already at the time you installed yours.

dedhed

oldbobcat

Sometimes the pivot on that side gets tight because of dirt, wear, or loss of lubrication on the bushing. Sometimes a thorough cleaning plus a shot of thin lubricant will loosen it. If that doesn't work, you'll have to loosen the pivot. Generally, these are an Allen bolt in front into a nylock nut in the rear arm. There might be a grub screw underneath, too. So loosen the grub screw, loosen the pivot bolt a whisker, test, and tighten the grub screw. Don't loosen it so much that you can twist the arm out of alignment. Then squirt a drop of light lube into the pivot.

And since you're not using the reflector holder attached to the mounting bolt, lose it. It only gets in the way.

maddog34

Test first, fix once... Remove the wheel..squeeze brake lever.. WATCH to see if both sides of the brake respond the same... if so, you have an ALIGNMENT issue with the Brake Caliper... if one side barely moves, you have a sticking brake problem.

you can solve an alignment issue by loosening the mount nut and then closing the brake on the recently reinstalled wheel.. then tighten the Nut CAREFULLY While Holding the Brake Lever Tightly, Watching to ensure the Caliper doesn't twist out of position as you tighten.... i hold the caliper as i tighten the mount nut.

Gosh

Thanks all for your prompt responses. Here’s a YouTube link thanks for the suggestion Iride01

I have tried all sorts of combinations of cable tension, centering screw positions and have started with the barrel adjuster full out to give maximum loosing but still the non spring side doesn’t open to take up the slack as shown although I accept I might have made things worse. I haven’t tried lubricating the pivots so I will try that thanks for the instructions Oldbobcat. (By the way that’s a bracket to fix a mudguard not a reflector holder). I will take wheel off first as per Maddox 34 suggestion - a simple thing which never occurred to me. I’ll report back tomorrow.

HillRider

Nope, I've never had a "direct mount" side pull brake of any kind. I've got older 105, Ultegra and Dura Ace dual pivots with either nutted or recessed nut mounting. These all date from 2005 or earlier and that was well before direct mount calipers were even though of. As I mentioned you can set the pad gap by adjusting the cable length, center them by hand and then tighten the mounting bolt/nut to keep them from moving off center. It's never failed.

The only brakes I've needed the centering screws for were V-brakes and cantilevers and those just controlled the return spring tension.

Iride01 

Okay.... I guess.

I see what you are saying and don't really disagree that you can center them that way. However the centering screw is there and it works too. So I guess I'll just assume you were pointing out an alternate way to do the centering.

dedhed

What is the history of post-mounted centerpull brakes?

smd4

What’s with all that clicking when you manually move the arm??

Gosh

It was sticky pivots which were stopping the brake from snapping open and pulling the cable tight between the barrel adjuster and pinch bolt. I was able to take apart the brake, clean and regrease and issue solved. I wasn’t aware you could do that so thanks again for suggestions and advice above. This video shows brake cable issues like mind with the calliper not releasing with some advice on how to recondition the brake.

smd4

Still don't understand the clicking, even with sticky pivots. Sounded like you were moving an indexed shift lever.

Trakhak

Probably the brake lever first sagging downward (when moving the brake arm around relaxed the cable tension) and then clicking against the lever body when the cable tension was restored.

tFUnK

The section of housing by the seat seems too long, it may be pushing on the caliper arm, preventing it from opening back up fully.

Gosh

Apologies for delay in replying. The clicking in the video when I moved the calliper by hand was the cable end in the lever hitting its stop as there was not enough spring tension on the cable because of the sticky pivots. Once the pivots were clean and regressed the spring was able to work properly to release the callipers and hence tension the cable.