7/16/14 2:28 PM

IIRC, there are actually two versions of them. Regardless, I get a faint high-pitched squeal from the rear (noticeable, but not annoying), but nothing from the front.

One thing to keep in mind is that it's not only the rotor manufacturers that have to maintain tight tolerances; if the mounting points on the hub aren't machined perfectly, they can pull a rotor out of true. I've seen this with a rotor that was perfect on one wheel, but not on another. While the XX rotors are quite stiff, mine were pretty true to begin with and they did respond to a firm hand when fine-tuning them.

7/16/14 7:01 PM

true, very important.

in this area Avid got their brake designs nailed: their caliper fixing bolts have these neat concave/convex washers that let you mount the caliper *perfectly* aligned no matter how badly askew the mount-points may be. loosen bolts, pull brake lever firmly, tighten bolts...DONE!



edit: i just re-read your post...yes, the hubs can certainly be effed up, too! i gotta think that most modern hubs are CNC machined and that rotor mounting-plane should come out pretty dang straight.

7/16/14 7:14 PM

I wound up using the extra avid bolts/parts to secure the front Shimano CX55 caliper on the Reubin. After paying for the Shimano brackets, the bolts would not work. I futzed with it for a while before using parts left over from the BB7s set to get the Shimano to work.

I will buy the BB7s again and not the Shimanos honestly. But the Juicys on my Klein work a lot better, although I can not see why the cable for road would not work well. So 3 sets of BB7s so far and no fuss no muss and parts left over, unlike Shimano in my particular experience... Yada

Last edited by Sparky on 7/17/14 8:16 PM; edited 1 time in total

7/17/14 7:56 PM

disc brakes can squeal.

well, when i ride my merckx with retro super record side-pulls...they squeal like a stuck pig. makes me really popular in the group rides!

maybe when bicycle disc brake designs are as mature as side-pull designs, we'll be laughing about how badly they used to squeal "back in the day".

7/18/14 5:30 AM

Good side pull calipers seem to have solved the squeal problems. i've used a variety of Shimano and Tektro double pulls and never had any noise problems.

However, cantis have been around just as long and still have problems. I was never able to get my Shimano's reliably quiet and, based on what I read, lots of other have the same problems.

7/18/14 5:42 AM

1. My disk brakes squealed more and louder than all the rest of the brakes I've ridden in over 40 years put together, and that includes Mafac Racer centerpulls as well as a variety of cantis. The disks work fine now after much work and part replacement, so the problem is not inevitable, but my opinion remains that they are much touchier than other types of brakes.

2. There are different levels of squealing, but IMHO "like a stuck pig" is intolerable and I won't ride such a bike. I've never had that on a sustained basis (couldn't be readily fixed) other than with the disks. In my experience with sidepulls, centerpulls and cantis you can fiddle with them and get rid of or greatly reduce the screech.

YMMV

7/18/14 7:49 AM

"in this area Avid got their brake designs nailed: their caliper fixing bolts have these neat concave/convex washers that let you mount the caliper *perfectly* aligned no matter how badly askew the mount-points may be. loosen bolts, pull brake lever firmly, tighten bolts...DONE! "

It depends greatly on the caliper action and whether or not the cable housing or hose puts any side-load or twisting moment on the caliper, but most of the time I have to fiddle with these good bolts/washers while manually skewing the caliper a bit to get things well-centered.

As for cable actuation on road disc calipers, it can work quite well, at least until one tries a set of hydraulic calipers (attached to normal cable-op levers) or full hydraulic, then a great deficiency seems to appear with respect to "lever flex" felt with the BB7's or whatever.
I believe Jagwire developed their compressionless brake cable housing to address this deficiency with non-hydro calipers.