Disk Brakes: Centering Calipers w/o using pads?

"(Pete Cresswell)" <[email hidden]> wrote in message "]news:[email hidden]...

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This last set of pads I've put in are giving me fits. Previous two sets haven't been bad at all.

Can't seem to get this pair centered right.

Now, after a few hundred miles of fooling around, it's to the point when I

mic

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them, each pad has a different thickness on different edges.

I'm assuming that even new pads aren't perfectly true - so it seems like

the

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Good-Right-And-Holy path would be some method of getting the calipers

centered

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and parallel without using pads at all - then put the pads in and let any unevennesses work
themselves out with normal wear.

Am I on the right track?

I would think you'd need some kind of 'blank' to put in their place that is the same size/shape and
thickness. If you try to squeeze the pistons to the rotor they may become unseated and leak. It may
just be dirt built up inside the caliper not allowing the pads to travel evenly to the rotor. Give
it a good cleaning inside with alcohol and try new pads. What brand brakes are they?

Mike

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What brand brakes are they?

Hope C2's.

Haven't had any probs with (EBS?) "Green"s - and I've been through a few sets, but both pair of Hope
pads I've used have given me fits noise-wise. I think it's something about the higher metal content
being less tolerant of misalignment.
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PeteCresswell

"(Pete Cresswell)" <[email hidden]> wrote in message "]news:[email hidden]...

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RE/

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What brand brakes are they?

Hope C2's.

Haven't had any probs with (EBS?) "Green"s - and I've been through a few

sets,

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but both pair of Hope pads I've used have given me fits noise-wise. I

think

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it's something about the higher metal content being less tolerant of misalignment.
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PeteCresswell

My Mini's were the same before I started with the EBC Greens. I used to say "I 'Hope' they stop
squealing!" Do your calipers mount the same as Mini's? Meaning, do you use shims to center the
caliper to the disc rotor? If so it's possible it's the dirt/binding thing I mentioned that is
causing your uneven wear problem. The other thing Hope Tech told me is to have the caliper mounts on
the frame faced to ensure they are perpendicular to the wheel axle. Magura makes a tool for that and
I believe Hope does now as well. Check with LBS's in your area for this service.

Mike

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Meaning, do you use shims to center the caliper to the disc rotor? If so it's possible it's the
dirt/binding thing I mentioned that is causing your uneven wear problem.

Yes, they need shims. Searched far and wide for the precision washers, wound up with a little bag of
open-ended thingies. Less time-consuming to add/remove while searching for the magic spot, but I'd
still like to get some real washers for permanent use. The open-ended things seem like they'd fall
out easily and they aren't carrying the load evenly.

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The other thing Hope Tech told me is to have the caliper mounts on the frame faced to ensure they
are perpendicu

I don't think I want to go there because it already takes a half-dozen shims to get the pads near
center. Worst case, I think I'll just go back to greens and stick with them. Dunno what got in to me
ordering a second set of Hope pads...pure masoschism, I guess.

Has anybody tried "yellow"...the sound like a step down from "green" in durability...but I'm
guessing each step down in durability carries some upside in some other characteristic.

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PeteCresswell

Magura's tech support guy says to center the calipers WITHOUT the pads. Line the rotor up with the
parting line in the calipers. It is much much easier to get them lined up that way.. using shims of
course, and possibly more shims on one side than the other.. whatever it takes to get perfect
alignment... NEVER touch the levers when doing this.

Now put the pads in .. take a short ride to break them in.. then if the gap is greater on one side
then the other.. push the rotor against the pad that is too close to the rotor and have someone
hit the brake handle... that will move the self adjusters just a little bit and that usually
equalizes the gap.

that's how i do mine.

charlie

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o have the caliper mounts on the frame faced to ensure they are perpendicular

I think you've put me on to something with that. I looked more closely at the insides of the mounts.
Ellsworth has coated that area with some very heavy plastic-like coating - much thicker than any
paint I've ever seen.

Turns out the stuff is starting to peel off there - causing an irregular surface where the calipers
and shims bear.

I trimmed it with a razor blade and then took a leaf out of the Avid book: I slackened the mounting
screws a lot, then cranked down the adjustment on the calipers (C2s are a closed system and it
allows that) until they were squeezing the rotors pretty hard. Then I slipped shims in to the
resulting spaces between caliper and frame until no more would fit - and I *did* find a substantial
diff between the number of shims that filled up the front and rear spaces - suggesting that the
mounts weren't parallel (although I wouldn't be too sure until I've ridden the thing for
awhile...too many other variables....)

Also, the fact that my skewers used to fit perfectly when installing/removing the rear wheel and now
I have to loosen them a few turns when installing to work with the slop between the drops and the
hub suggests that something more than just paing has gone goofey with that area.

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PeteCresswell

"(Pete Cresswell)" <[email hidden]> wrote in message news:<[email hidden]>...

[snip]

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Has anybody tried "yellow"...the sound like a step down from "green" in durability...but I'm
guessing each step down in durability carries some upside in some other characteristic.

Dear Pete,

Earlier in this thread, you mentioned pads giving you fits noise-wise and now I notice that you're
talking about different-colored pads and mentioning yellow.

Deep in the bowels of the nearby thread about "6 or 8 inch rotor" brakes, Jobst Brandt is trying to
get brake basics through my thick head and listed this link:

koolstop.combrakesOpen ↗

All the way at the bottom of this web page are the various kinds of KoolStop pads, with their colors
and claimed qualities. The very last two are weird-looking hybrids, with the front half one color
and the back half a different kind.

One hybrid pad is called the "Stinger" and has a short yellow front section and a larger black
section and is supposed to help reduce noise.

I've asked Jobst what he thinks of this, guessing that the answer is "not much," but he may surprise
me. Maybe the brand that you like is offering the same sort of mixed-composition pads for
noise problems?

Carl Fogel