Caliper disk brakes
 

Hi new to here can someone help me understand why my jak-5 cable disk brakes aren't stopping bike with new pads installed it's really p*****g me off.
https://cimg6.ibsrv.net/gimg/bikefor...1beaece945.jpg
https://cimg3.ibsrv.net/gimg/bikefor...bb921c53f9.jpg

well, from what little i can see in those pics.. the cable is not adjusted correctly, the caliper is also Not adjusted correctly, the caliper pivot cups/cones are not installed correctly, and the bike, in general, needs better care.
there's a strong possibility that the disc is contaminated with something too, but there is no pic of the disc, so who knows what it looks like, other than you, eh?

prepare to get comments about your JAK brakes, since most people trash talk low end bikes and their inexpensive components.

what type of pads did you install? Organic/Resin, Semi-Metallic, or Metallic?
what brand/type of disc is involved?
is there a bike Co-Op near you? go see them, and ask for help.

the pivot cups/cones should be installed so that the dark parts touch the caliper mount ears, and the light colored parts touch the frame mount/bracket and allen screw head/washer... the allen head end is correct, the frame mount end is reversed..
that will make aligning the calipers easier, but won't dramatically effect braking...

youtube has dozens of videos on the correct way to adjust disc brakes on bikes, but you may still want to hit up any local co-op for help.
we work cheap, and do this sort of thing for a living.

I know it's not a high-end bike like Trek, but for me, if it gets pinched, I'm not out of pocket too much. As for the pads, they are resin. The rotor is in good condition, cleaned using isopropyl 99%. I've added more pics. For the bike shop, there isn't any near me; smh. I've got all the tools I need; just need some help.https://cimg8.ibsrv.net/gimg/bikefor...dca6831a60.jpg
https://cimg1.ibsrv.net/gimg/bikefor...d2bd48838c.jpg
https://cimg7.ibsrv.net/gimg/bikefor...a72d9eb2f0.jpg
https://cimg9.ibsrv.net/gimg/bikefor...ee910391e9.jpg
Look ok to me what do you think.
https://cimg3.ibsrv.net/gimg/bikefor...535b5bcb3b.jpg

I found a real clear video showing changing those pads. His had rusty bolts too. LOL It has only one moving pad. Usually a lame design.
But this guy showed the front brake lifting the rear of the bike.
Expecting much from cheap parts on any CHEAP bike is laughable.

Was it on a electric scooter I can't find any

In this shot, the actuating arm is in the fully-on position - you need to remove the cable then wind in the pad adjuster (the screw behind the inner pad) until the wheel won't turn, then back it off enough to let it turn and reconnect the cable. That might be it, if it turns without rubbing and stops when you pull the lever then job done, but you may need to re-centre the caliper - slacken the mounting bolts*, apply the brake hard a couple of times then hold it on while you retighten the mounting bolts. If all goes well that's about it, but this process can involve multiple attempts to get everything right - slacken the bolts, twist the caliper, tighten the bolts ... you need to be able to see the gap between the rotor and the pads to tell where it's rubbing, or if one pad is further away than the other - a flashlight can help, or placing something white under the wheel to make the gap easier to see.

* the bolts that go through the caliper, not the ones that go through the fork.

Here’s instructions for adjusting BB7 from Avid. Not the same brake but close enough to use the instructions. You like the ability to adjust the pads on the arm compared to the BB7. The key is that you don’t what much lever movement from unengaged to locked. Mechanical brakes work best if the lever has a very short throw.

Doesn’t get much shorter than in that photo

Does this caliper arm need ever need adjusting thanks guys..
https://cimg8.ibsrv.net/gimg/bikefor...d0462103d1.jpg

No. Your anchor point on the cable is too high up as has been pointed out but that is because your pads aren’t adjusted properly nor is your caliper properly centered.

that screw attaches the cable arm to the moving pad's cam system... leave it as it is... the "Adjustment" is on the back side of the caliper, and moves the "non-moving" pad inwards toward the disc. SOME of those adjusters are held by a small allen set screw, and attempting to turn the adjuster, without temporarily loosening that set screw, will ruin the adjuster...

did you properly install the caliper alignment cups/cones yet?

What are you going on about? First those aren’t “cup/cones”. They are spherical washers. I also don’t see anything wrong with the way they are installed.

Should they have all the convex washers (I'm assuming the black ones) against tne caliper, for maximum adjustability, so they approximate actual spheres and work like balljoints? I didn't spot that. It may not make much difference.

It shouldn’t make that much difference.

Not yet i understand it now so hopefully i can get them right if not it could be the pads
themselves fingers crossed ....

common name is Cups/Cones...
and the way the two closest to the frame are installed defeats their purpose, making them merely spacers.
that means it makes a difference.

i'm "going on" about helping someone get their brakes sorted out.
smh.

Are you aware that the hex on inside of the caliper (wheel side) under the pad is a pad adjuster?

The spherical washers look fine.

O.p. needs to take the bike to a co-op, LBS, or bike mechanic friend. If they had the ... whatever it is, to make those brakes work, they would be working. Videos help people who have the innate ability to make sense of mechanical things. They usually have been able to get into the ballpark without help, but a video can crystalize some of the minutiae. The quality of the pictures taken, the vagueness of the o.p. line of questioning makes it clear that they would not understand written instructions which is all anyone here can provide.

I personally have found that rear discs, especially on tandems, need pre-load to make them work well, or at all. In the o.p. picture, the anchor bolt is fully sunk to the 'rest' position, which is not in itself evidence of no preload but I'm not betting that they know it's necessary. On the picture of the front caliper, the anchor bolt is barely off of the fully actuated position. That wheel should barely turn. Throw in the shop towel and get local hands on help, o.p. That is the way.

Nope. They are not a “cone”. A cup and cone system in a bicycle context is meant to allow bearings to roll around an axle in only one orientation. The spherical washers on the brakes is meant to allow for movement in different orientations. They allow for rim brakes to be toed to the rim, for example, or in this case allow for the caliper to the tipped if needed in different directions.

For the most part, they are just spacers. Spherical washers aren’t needed on disc brakes and many brands don’t use them anymore. But even in the configuration that azzzaoo6’s brakes are set up, the spherical part of either washer can rotate in any direction the same amount independent of the orientation.


No. It doesn’t. You could replace them with spacers and the brake would set up much the same way that it does now.

​​​​​​​Not by bringing up red herrings.

Plus, the convex washer is in no way conical in shape.

Pic #2 shows the inner pad Adjuster's SET SCREW i mentioned earlier... that tiny, nearly hidden set screw WILL need to be loosened before adjusting the inner side pad. and the adjuster appears to be backed out to the point of the inner pad not contacting the disc, possibly......
and i'd put a tiny drip of Penetrating oil on that screw before trying to loosen it ;)

the pivot cups/cones are now properly assembled on the REAR brake.. the front caliper mounts are next, right?
the rear brake cable is now in the "normal" range...

adjust the front brake's cable to look like the rear brake, adjust the inner pads, re-tighten the set screw, align the calipers as shown on the 'tubes, and go enjoy your bike :)

Under that crusty heap of aluminium oxide? I think it might take more than a tiny drip - probably best to apply it with the pads removed, to save them from contamination. Worst case he can drill it out and tap it for a larger screw, or use loctite on the adjuster.

You mean this?
https://cimg0.ibsrv.net/gimg/bikefor...154402243.jpeg

To many of the same pictures in this thread and not enough words. I can't even find the few replies that I was hoping to see the response to. <grin>

yep. Set screw... it will ruin the threads on the adjuster if someone attempts to move the adjuster without loosening it... and will mangle the threads is OVER-tightened too.