disc brake spring wedged between pads and rotor

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disc brake spring wedged between pads and rotor

Postby eeksll » Wed Aug 14, 2013 9:57 pm

at least thats what I assume has happened. Any ideas what has cuased this and how I can have it not happen again? or is it just showtime happens sometimes.

I am pretty sure it happened due to a single incident cause there was no squeak then there was constant rubbing. Nothing really noticable though, I dont think I was even braking, think I was going uphill, commuting on shared path. Probably didn't help I jammed the brakes on hard a few times to try and get rid of the squeak.

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by BNA » Wed Aug 14, 2013 10:06 pm

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Re: disc brake spring wedged between pads and rotor

Postby Duck! » Wed Aug 14, 2013 10:06 pm

Worn pads.
I had a thought, but it got run over as it crossed my mind.
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Re: disc brake spring wedged between pads and rotor

Postby A_P » Wed Aug 14, 2013 10:16 pm

Is it just me, or does it look like the pads have been running a little low on the rotor?
how worn are/were the pads.
I have avids, not seen this before
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Re: disc brake spring wedged between pads and rotor

Postby }SkOrPn--7 » Wed Aug 14, 2013 10:57 pm

Your pads got over heated over a few times which caused the spring to soften and move getting caught. Next time alternate between front and rear to give pads enough time too cool down before they have to work again.

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Re: disc brake spring wedged between pads and rotor

Postby eeksll » Wed Aug 14, 2013 11:08 pm

worn pads ... new ones are on now :)

There is 1 pad where the top section is worn off, I had originally assumed that was caused by this incident, but now thinking about it, maybe not? There definitely is not a gradual wear, its a step down and not a distinct step down. It looks like that bit was ripped off. Maybe it just got so thin, the top just crumbled away?

I tried to take a photo of it but my camera skills cant seem to get that bit in focus. I need a macro mode or something like that.

A_P, the top half being worn off, is that why you think they are running low? I just put new ones on, fairly sure its not running THAT low.
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Re: disc brake spring wedged between pads and rotor

Postby eeksll » Wed Aug 14, 2013 11:12 pm

}SkOrPn--7 wrote:Your pads got over heated over a few times which caused the spring to soften and move getting caught. Next time alternate between front and rear to give pads enough time too cool down before they have to work again.

Ricky


Ill keep that in mind, but given the path I commute on and the non-neccessity to actually brake, plus the speed at which i commute, i really really dont think thats likely.

thinking about it now, and looking at the new springand pads, i guess with that design, as the pads get low, it would be pretty easy for the rotor to catch the spring. especially since the bottom arm of the spring sits up a little.
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Re: disc brake spring wedged between pads and rotor

Postby queequeg » Thu Aug 15, 2013 6:26 am

I have had the same thing happen, and as stated above, it is worn pads. You are supposed to replace the pads well before they get that far, as essentially the spring clip has contacted the disc rotor and torn off. You are almost to the grinding metal phase by then!
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Re: disc brake spring wedged between pads and rotor

Postby bychosis » Thu Aug 15, 2013 7:12 am

queequeg wrote:I have had the same thing happen, and as stated above, it is worn pads. You are supposed to replace the pads well before they get that far, as essentially the spring clip has contacted the disc rotor and torn off. You are almost to the grinding metal phase by then!


+1 Me too, with avid juicy brakes. Turned around, walked back up the hill and drove to work that day. Been alittle more cautiosu since then watching pad wear.
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Re: disc brake spring wedged between pads and rotor

Postby FuzzyDropbear » Thu Aug 15, 2013 9:55 am

A_P wrote:Is it just me, or does it look like the pads have been running a little low on the rotor?
how worn are/were the pads.
I have avids, not seen this before


They do look a little low, however, when I installed my BB7s on the 200mm rotor they looked to be in a similar position to what's shown in the pic, I had to space the caliper out further to get it to where I wanted it. Now it runs nicely around the rotor with the pad in full contact with the outside ring. The Avids are the only ones I've seen to have had this sort of positioning (not that I've seen all the disc brake setups out there).
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Re: disc brake spring wedged between pads and rotor

Postby A_P » Thu Aug 15, 2013 11:24 am

on all my bikes, the rotor wear is within 1/2mm or less of the outer edge of the rotor.

Image

the OP's rotor wear looks to be about 3-4mm in from the outer edge.
If nothing else your losing braking power
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Re: disc brake spring wedged between pads and rotor

Postby FuzzyDropbear » Thu Aug 15, 2013 1:04 pm

A_P wrote:on all my bikes, the rotor wear is within 1/2mm or less of the outer edge of the rotor.

Image

the OP's rotor wear looks to be about 3-4mm in from the outer edge.
If nothing else your losing braking power


Hmm, I'm assuming they're avids? That's where I have mine set but still had to put some shims in to get there, even with the correct adapter. Strange.
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Re: disc brake spring wedged between pads and rotor

Postby cobba » Thu Aug 15, 2013 1:23 pm

An Avid brake caliper without the CPS washers between it and the brake adapter could cause a wear pattern on the rotor like that.

A CPS washer stack is about 4mm thick.

Post a photo of the disc brake caliper mounted on the adapter.

.
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Re: disc brake spring wedged between pads and rotor

Postby eeksll » Thu Aug 15, 2013 9:01 pm

A_P wrote:on all my bikes, the rotor wear is within 1/2mm or less of the outer edge of the rotor.

Image

the OP's rotor wear looks to be about 3-4mm in from the outer edge.
If nothing else your losing braking power


thanks for pointed that out. When I get home Ill take some pics and post them up see what you guys think. Can't ever have enough braking power :).
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Re: disc brake spring wedged between pads and rotor

Postby Dragster1 » Thu Aug 15, 2013 9:49 pm

Avid brakes are a nightmare to me, If you brake hard like me and the conical washers move, no matter how many times you retighten them and adjust them. The calliper ends up slightly rubbing on the disk when its too close and it only happens on the front for me.
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Re: disc brake spring wedged between pads and rotor

Postby eeksll » Thu Aug 15, 2013 11:29 pm

Image Image Image

havent really had a problem with the brakes, but i don't slam on the brakes unless i need to. Which was probably only during my brake rotor "burn in" stops.
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Re: disc brake spring wedged between pads and rotor

Postby boyracer » Fri Aug 16, 2013 12:41 am

With bb5/7 the problem could be that you have run out of adjustment on the out side pad. You state pads are v.worn, have you adjusted them a lot?
If you pop the red cover off, you'll see a threaded pin ( that incidently is the same size as a schrader valve core tool). hold piston in with fingers, wind it back onto this adjuster, re fit pad, then wheel and you're off riding again.

If your brakes are coming loose when you 'jam 'em on hard' as one respondant said you're doing it wrong.....see your friendly LBS and please stay well away from where i ride.
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Re: disc brake spring wedged between pads and rotor

Postby FuzzyDropbear » Fri Aug 16, 2013 1:16 pm

Yep, you seem to have the same problem I had. I moved the caliper by putting a couple of washers between the mount and the caliper itself and it was enough to move the pad further out to the edge of the rotor. Is this a common thing for BB7's? I thought it was only mine that were odd..
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Re: disc brake spring wedged between pads and rotor

Postby Mulger bill » Fri Aug 16, 2013 7:00 pm

Nope, sorted with a couple thin washers.

Eeksl, maybe you set up your 7s different to mine (road) but IMO having the torque arm that low at rest must give you pretty slow response. I'd send you the details of the method I found online that works a treat for me, if I could find it (laptop maybe, hmmm :?)

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Re: disc brake spring wedged between pads and rotor

Postby eeksll » Sun Aug 18, 2013 12:08 pm

Ill go get my self some washes today. Had a look at my bb7 box and it looks like i get 2 washers, but according to the instructions they sit behind the bolt head so no help in raising height there. This is a pic of some of the spare parts that came with the bb7's, what is the little rubber o-ring for? I had a bit of a google but couldn't find any real info on those.

Image

Also it looks like the MTB which is running avid juicy also have the same issue, the front seems ok but it could probably be raised a touch, but it is evident on the rear.

Image Image

Mulger bill wrote:Eeksl, maybe you set up your 7s different to mine (road) but IMO having the torque arm that low at rest must give you pretty slow response.

Not that I have noticed, but it is the only cable operated disc brake i have ever used, so thats all I know. I have set it up so that any touch on the lever starts moving the brake arm, after installing the new pad, I think i can tighten it up a smidge, there is a very very slight bit of slack.
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Re: disc brake spring wedged between pads and rotor

Postby queequeg » Sun Aug 18, 2013 12:15 pm

eeksll wrote:Ill go get my self some washes today. Had a look at my bb7 box and it looks like i get 2 washers, but according to the instructions they sit behind the bolt head so no help in raising height there. This is a pic of some of the spare parts that came with the bb7's, what is the little rubber o-ring for? I had a bit of a google but couldn't find any real info on those.

Image

Also it looks like the MTB which is running avid juicy also have the same issue, the front seems ok but it could probably be raised a touch, but it is evident on the rear.

Image Image

Mulger bill wrote:Eeksl, maybe you set up your 7s different to mine (road) but IMO having the torque arm that low at rest must give you pretty slow response.

Not that I have noticed, but it is the only cable operated disc brake i have ever used, so thats all I know. I have set it up so that any touch on the lever starts moving the brake arm, after installing the new pad, I think i can tighten it up a smidge, there is a very very slight bit of slack.


The BB7 brakes are not adjusted with cable tension. Pull the cable through as tight as you can get it and tighten the bolt. The pad clearance is then adjusted on each side with the inboard and outboard dials. When fitting the calipers, you should centre the rotor slightly offset (as per the instructions).
As the pads wear, you just adjust the dials as required. You should never need to worry about cable tension.
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Re: disc brake spring wedged between pads and rotor

Postby Duck! » Sun Aug 18, 2013 12:19 pm

The o-rings keep everything together when you remove the caliper & adaptor in one set.

Assembly sequence: Bolt -> flat washer -> cupped washer -> domed washer -> brake caliper -> domed washer -> cupped washer -> adaptor (if you're stepping up from mount for 140mm rotor to 160mm rotor, or 160mm mount & 180mm rotor) -> o-ring.

That's providing you need to use the post-mount extension adaptor that's pictured. You don't need the o-rings for an IS - post-mount adaptor, such as in the earlier pics.
I had a thought, but it got run over as it crossed my mind.
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Re: disc brake spring wedged between pads and rotor

Postby eeksll » Thu Aug 22, 2013 12:20 am

thanks duck. It would also be useful to have something keep all those damn washers on, i dropped them so many times.

2 washers had the bottom of the pad just below inner circle of the rotor, 3 went to high. Also concerned with 3 washers, the amount of screw in the post was getting short.
Image

one other thing i found with the bb7 is they have a tension adjust screw and i noticed its basically all the way in. Is this normal?
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