Neo Jet Break Squeal

[eDean]

Hi,

2 week in and 240 miles an my bike has a horrific squeal from the rear brake. I have centered it twice (loosen break screws, hold break lever, tighten screws) but nothing work. Not only does it squeal but it also resonates. On one ride someone yelled at me for being too loud in a residential neighborhood.

An odd side note is when I got the bike in a box and was done assembling it the right brake lever was adjusted so that even under full pressure the back break only partially engaged. I tighten the screen under the brake lever to correct this and that is where the problems started. My front break is great. Sound aside the breaking performance is excellent on this bike. I'm not very experienced working on disk brakes and will most likely take it in when the biking season is winding down. Looking for a quick fix if you have any ideas.

 

[Peter]

I also have a BH bike with disk brakes. They also make noises from time to time. Not always. My dealer says there is not much to do about it.
Its just a disadvantage that comes with diskbrakes.

 

[Tom P]

Did you try to wipe the disks down with rubbing alcohol?

 

[Shea N Encinitas]

Is there any light between the pads and disc? You may need to back off the cable and adjust the inboard pad closer to the disc.

 

[lilrich1959]

The Jet utilizes a hydraulic brake set so contrary to Shea's reply which would be for cable operated disk brakes. Hydraulic disks as on the jet engage both pads via pistons in the caliper when operating correctly both pads advance toward the disk equally and are retracted by a spring insert between the pads. Centering the caliper is essential, to do so loosen the two socket head allen bolts retaining the caliper to the adapter so that the caliper can float side to side. Hold the brake lever firmly so the pads are pressing on the disk and retighten the bolts while holding the lever. This will ensure even engagement of the pads. Squealing is caused when the leading edge of the pad nose dives into the disk, or pad is glazed from heat and over braking. Aligning the brakes will resolve the nosedive if pads were set up properly initially. If pads were wore unevenly (wedge shaped) due to wear after improper alignment you will need to replace pads. Glazed pads can be reconditioned with wet dry sandpaper to remove glaze make sure to wipe clean to remove embedded abrasive grit. Also making a slight bevel on the leading edge of pad will help too. Remember when working with hydraulic brakes to avoid engaging lever when caliper or disks are removed as there is the possibility of pushing out the pistons or wedging the pads. Never loosen or remove any hydraulic lines unless you are versed in proper bleeding procedures for your particular system. Disk brakes can be difficult to run silently as the disk and motor housing act much like bell, setting up a harmonic vibration and amplifying any induced noise. With a little patience and skill a well set up hydraulic disk brake will provide superior stopping with minimal maintenance.

 

[Shea N Encinitas]

Nana nana boo boo, stick my face in doo doo. This was probably after my 18th mech brake adjustment & I assumed the whole World was with me. Nice description on Hydro tweaks BTW. -S

 

[Mtnm]

Hi,

2 week in and 240 miles an my bike has a horrific squeal from the rear brake. I have centered it twice (loosen break screws, hold break lever, tighten screws) but nothing work. Not only does it squeal but it also resonates. On one ride someone yelled at me for being too loud in a residential neighborhood.

I found this link helpful: http://www.pinkbike.com/news/Tech-Tuesday-Silence-That-Squeaky-Disc-Brake-2011.html
About 20-30 very hard stops from the 15-20 mph range eventually solved the squeal.
Previously I had touched up the rotor using a scotch brite pad, but the hard stops seemed to actually solve the problem.

Mike
Colorado, USA

 

[eDean]

I found this link helpful: http://www.pinkbike.com/news/Tech-Tuesday-Silence-That-Squeaky-Disc-Brake-2011.html
About 20-30 very hard stops from the 15-20 mph range eventually solved the squeal.
Previously I had touched up the rotor using a scotch brite pad, but the hard stops seemed to actually solve the problem.

Mike
Colorado, USA

 

[eDean]

After trying about three times to realign the brakes, sanding them, and trying different methods to be the disk I finally gave in and took the bike to a bike shop. Fresh bikes in Bethesda was able to resolve the problem where the squeal is still there but barely audible.I didn't get a chance to talk to the tech who worked on it but it was a $20 fix which means they didn't spend any time so must've been something very straightforward. I'll find out what they did at some point and post.

Thanks for all the help some of the things here work better than others. They all helped reduce the squeal at least for a while.