Cycling and bicycle discussion forums. 
   Click here to join our community Log in to access your Control Panel  

Go Back   > >

Bicycle Mechanics Broken bottom bracket? Tacoed wheel? If you're having problems with your bicycle, or just need help fixing a flat, drop in here for the latest on bicycle mechanics & bicycle maintenance.

User Tag List

Thread Tools Search this Thread
Old 11-26-12, 06:23 PM   #1
Portland, OR
Thread Starter
i_r_beej's Avatar
Join Date: Jun 2006
Bikes: Cannondale: '94 R400; Lemond Poprad '06; Specialized Epic Marathon '06; Specialized Stumpjumper '89; Redline Proline Pro Cruiser '10
Posts: 318
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
TRP 8.4 brakes: spring tension setup question

Hey all,

I recently installed TRP 8.4 linear pull brakes on my cyclocross bike. They are a vast improvement over the conventional (old-fashioned) cantilevers they replaced.

There is only one little issue that's threatening to drive me crazy: The uneven actuation of the brake arms.

Here's what's going on: When I squeeze the brake lever, the arm with the noodle moves to the rim first, THEN the other arm moves. I've experimented with the spring tension extensively and I've also disassembled the pivot sleeves and lubed them with some Rock-n-Roll Super Slick. Nothing seems to make any difference. (New cables and housing were installed at the same time as the brakes.)

The bottom line is that the braking performance seems unaffected (I can lock up the wheels with just one finger on the brake lever!) and so I suppose that the uneven actuation of the arms is a cosmetic issue. But it still bugs me, especially since I have a few other bikes with various brands of linear pull brakes and none of them exhibit this behavior (both brake arms actuate evenly with a pull on the brake lever).

Has anyone else seen this? Do you have a"fix"? Or should I just relax?

Thanks for reading.
i_r_beej is offline   Reply With Quote
Old 11-26-12, 06:29 PM   #2
Senior Member
Join Date: Aug 2005
Location: Pittsburgh, PA
Bikes: '''96 Litespeed Catalyst, '05 Litespeed Firenze, '06 Litespeed Tuscany, '12 Surly Pacer, All are 3x8,9 or 10. It is hilly around here!
Posts: 30,245
Mentioned: 20 Post(s)
Tagged: 0 Thread(s)
Quoted: 642 Post(s)
It's really not a problem as long as both pads retract fully when you release the lever. As you said, the braking performance is good so I view it as an annoyance, not a defect. Symmetry is nice but performance is what counts.
HillRider is offline   Reply With Quote
Old 11-26-12, 07:14 PM   #3
Senior Member
dsbrantjr's Avatar
Join Date: Sep 2010
Location: Roswell, GA
Bikes: '93 Trek 750, '92 Schwinn Crisscross, '93 Mongoose Alta
Posts: 5,412
Mentioned: 4 Post(s)
Tagged: 0 Thread(s)
Quoted: 365 Post(s)
Is it possible that your new cable housings are slightly longer than necessary and are exerting pressure on the arm with the noodle which is causing it to move before the other one? Maybe shortening the housing an inch or so will help the arms move evenly. Or just don't look at the brakes and just ride the bike.
dsbrantjr is offline   Reply With Quote
Old 11-26-12, 10:45 PM   #4
Senior Member
Join Date: Apr 2009
Location: New Rochelle, NY
Bikes: too many bikes from 1967 10s (5x2)Frejus to a Sumitomo Ti/Chorus aluminum 10s (10x2), plus one non-susp mtn bike I use as my commuter
Posts: 35,297
Mentioned: 105 Post(s)
Tagged: 1 Thread(s)
Quoted: 3642 Post(s)
It absolutely doesn't matter if one shoe strikes first. Once one arm makes contact the extra force transfers to the other. There's no side pressure on the rim except for a tiny amount reflecting variation in the springs. Compare to the disc brakes in cars where the piston is only on one side, once it touches the caliper moves across until the brake force is balanced on both sides.

There are spring balance adjustments, but those are only to make sure both sides release evenly.
Chain-L site

An ounce of diagnosis is worth a pound of cure.

“Never argue with an idiot. He will only bring you down to his level and beat you with experience.”, George Carlin

“One accurate measurement is worth a thousand expert opinions” - Adm Grace Murray Hopper - USN

WARNING, I'm from New York. Thin skinned people should maintain safe distance.
FBinNY is offline   Reply With Quote

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

All times are GMT -6. The time now is 02:30 AM.

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to and affiliated sites.
  • Ask a Question
    get answers from real people!
Click to start entering your question.