installin mah brakes

On Apr 19, 10:22 pm, Stephen Greenwood
wrote:
On Apr 19, 9:21 pm, landotter wrote:

Size up on the linkage cable

How does sizing up the linkage (straddle) cable help eliminate squeal?
I've never heard that suggested before. It changes the mechanical
advantage for actuating the brake, but that's in a direction that's
orthogonal to direction in which the pads move when they squeal.

Changing the straddle cable is about the only thing I haven't tried on
a front Avid Shorty 7 that I cannot de-squeal. I switched from stock
to Kook Stop salmon pads, I've cleaned the rims, and I've tried a vast
number of ever-so-slightly different toe-in adjustments. No luck.
Cleaning the rims with a Brillo pad wedged between the brake pad and
rim helps, but not completely, and only for a very short time. The
rear brake is the same type and the rear rim is the same, but that one
was fine on the initial adjustment. Because of that, and because I've
been successfully adjusting other cantilever brakes since 1994, I
figure there must be some intrinsic mechanical resonance in the fork/
brakes/pads/rim combination. That, and the squeal is a more pure tone
compared to other squealing brakes I've heard. Anyway, I'd be
interested to hear how it might help.

Thanks,
Stephen Greenwood


Have you mic'ed the post O.D. @ a few different points to get an
average and to see how much it varies, plus measure the I.D. of the
brake bushing @ both ends & from different positions again to look for
average & max variation. You could have an out of spec post or brake
bushing. Although I don't know what the clearance tolerance Min/ Max
should be. But excessive (whatever that is) can cause vibration. Many
cantilever posts are replaceable w/ a simple Allen key.
Perhaps Avid could tell you what the Min/ Max tolerance is, since they
are reasonably easy to access, or at least they used to be.

Good luck Jay

On Apr 20, 10:25 am, Stephen Greenwood
wrote:
On Apr 20, 10:10 am, landotter wrote:

It won't do squat. But it should slightly lower the mechanical
advantage and let ya at least remove the straddle cable w/o ****in'
with the barrel adjusters.

Right.

I haven't run cantis in a few years since the low-profile stuff became
popular--but they seem extraordinarily fussy to set up.

In my sample size of one, they have been. Besides the shorter arms,
the pads are different. They're thinner, and the mounting post is
positioned asymmetrically, whereas the Ritchey/KoolStop pads I always
used had the mounting post centered. Either of these could have
something to do with it.


With some of the Kool Stop asymmetrical pads, there is no need to set
toe in. They have a sort of a curved shape relative to the flatness of
the rim side. Just set them up w/ both the front & rear ends of the
pad touching & the toe in is set. Their instructions on the package or
maybe web site explain it better. Works for me.

Jay

On Apr 20, 12:13*pm, wrote:

With some of the Kool Stop asymmetrical pads, there is no need to set
toe in. They have a sort of a curved shape relative to the flatness of
the rim side. Just set them up w/ both the front & rear ends of the
pad touching & the toe in is set. Their instructions on the package or
maybe web site explain it better. Works for me.

Jay

Yeah, the Kool Stop V-type cartidge pads come with a small nub on the
leading edge for that purpose. I used it for my first attempt. It
worked fine for the rear brake, but something's unusual about the
combination of rim/pad/brake/fork I'm using.