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KnottedYet
05-23-2006, 08:06 PM
My linear pull brakes in front are being grumpy. The right (noodle) side pad drags against the rim after I use the brake. I can pull it away from the rim, but it will drag again after the next time I use the brake.

My Park Tool book covers taking apart and adjusting the whole she-bang, but doesn't do trouble-shooting. I tried twisting the adjustment barrel (without a clue what the heck I was doing) but it seemed to have no effect.

Can someone enlighten me? I just got the critter back from it's 90 day tune-up, so I'm sure it's just a little issue.

DebW
05-24-2006, 07:09 AM
I don't know really know what "linear pull brakes" are and much of my mechanic's knowledge is 30 years old, but since no one else has answered this I'll give you a few hints which may or may not be helpful. The problem is not in your cable or adjustment barrel, but in how the brakes center themselves around the rim. This is sometimes a tricky issue and not easily resolved, so you may need to find specifics about your brake model or visit your LBS. A few things that you could try, depending on the brake design: If the brake attaches to the frame with a single bolt, loosen the bolt, center the brake and retighten. If there is a single spring that connects both brake callipers, take a hammer and punch, place the punch on the high side of the spring, and give it a tap. If the brake pads are mounted on long posts (cantilevered brakes), you can loosen the bolt that holds the post in place and move it closer or further from the rim, then retighten. Good luck and let us know what actually works.

KnottedYet
05-24-2006, 10:10 AM
Bike Brake Haiku.

right brake pad dragging
three adjustments. which one works?
spring tension set-screw


Adjusted the set-screw so the spring tension would pull the arm off the rim again when I let go of the brake lever. Feel so studly now.... Went back to "undo" the fiddling I did on the cable barrel and the attachment bolt, tested it a couple times in my living room, then did my ride to work and back. Brakes worked fine!

DebW
05-24-2006, 12:18 PM
Congratulations. How convenient, a set screw to adjust the spring tension.

KnottedYet
05-24-2006, 04:58 PM
Ain't that just peachy? And I had no idea how to do ANYTHING with my brakes until this lil' problem popped up, and then I had to do some research and learned something in the process. (and fixed my brakes to my satisfaction!:D )

DebW: I saw in your profile you are an atmos sci. Who do you work with? My ex is an atmos sci, too. Now with the Forest Service doing fire weather.

DebW
05-25-2006, 05:28 AM
DebW: I saw in your profile you are an atmos sci. Who do you work with? My ex is an atmos sci, too. Now with the Forest Service doing fire weather.

I work for a small private research firm but have collaborations with a few university and government scientists. I do modeling of stratospheric chemistry, transport, and aerosols. Predicting ozone trends and changes in ozone due to CFCs, aircraft, volcanoes. Comparing measurements of various trace gases and aerosol properties with model predictions. There are some recent indications that large boreal forest fires at mid and high latitudes may inject aerosols and trace gases directly into the lower stratosphere via pyrocumulus convection. Does your ex know Mike Fromm at NRL?