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

Reply
 
Thread Tools Search this Thread
Old 04-16-14, 11:41 PM   #1
rekon
Senior Member
Thread Starter
 
rekon's Avatar
 
Join Date: Feb 2014
Location: Los Angeles, CA
Bikes: 2015 Cannondale CAAD10; 2014 Giant Talon; 2012 Bianchi Impulso
Posts: 455
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Disc Brakes Not Gripping

My front brakes were working fine earlier... However, I was messing the brakes to get rid of a noise from my wheel.

I did the following:
  • I loosened my caliper and tightened it while holding the front brake lever.
  • I loosened the anchor and pulled the cable.

Now my front brakes are not gripping at all. Excuse my noobness i'm pretty new at this. Please help.

Attached Images
File Type: jpg WP_20140416_004.jpg (68.0 KB, 19 views)
File Type: jpg WP_20140416_005.jpg (45.0 KB, 25 views)
rekon is offline   Reply With Quote
Old 04-17-14, 12:28 AM   #2
dabac
Senior Member
 
Join Date: Mar 2008
Bikes:
Posts: 5,360
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 8 Post(s)
If that really is all you did....
What happens when you squeeze the lever, does it go all the way into the bar w/o the brake biting?
In that case, you have too much slack in the system. You need to undo the cable clamp, pull the cable tighter, (= pull the end away from the clamp, downwards) then tighten the clamp again.
dabac is offline   Reply With Quote
Old 04-17-14, 04:05 AM   #3
clydeosaur
Senior Member
 
clydeosaur's Avatar
 
Join Date: Aug 2009
Location: Central PA
Bikes: Cannondale Six5, Specialized Stumpjumper FSR & old Hard Rock
Posts: 611
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
As stated, you might have too much slack in your cable. Readjust (you have a tension adjust where the cable housing enters the caliper). As well, you have pad adjustment. See the red thumb dial ? That will adjust your inboard pad. I can't see, but you might also have an outboard pad adjustment for fine tuning. You can watch the pads / rotor gap as you adjust. Keep in mind, you want to make sure your caliper is centered/aligned properly before doing all this. The other thing you will want to do is clean your rotors / pad surfaces as well to avoid noise.

Last edited by clydeosaur; 04-17-14 at 04:12 AM.
clydeosaur is offline   Reply With Quote
Old 04-17-14, 04:47 AM   #4
cobba
B A N N E D
 
Join Date: Aug 2006
Bikes:
Posts: 1,393
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Avid BB5 / BB7 Setup & Installation: http://cdn.sram.com/sites/default/fi...d7_English.pdf
cobba is offline   Reply With Quote
Old 04-17-14, 05:05 AM   #5
Kimmo
bike whisperer
 
Kimmo's Avatar
 
Join Date: Dec 2009
Location: Melbourne, Oz
Bikes: copy/paste links: http://velospace.org/node/36949 http://velospace.org/node/47746 http://velospace.org/node/47747
Posts: 7,099
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by dabac View Post
In that case, you have too much slack in the system. You need to undo the cable clamp, pull the cable tighter, (= pull the end away from the clamp, downwards) then tighten the clamp again.
Because of all the mechanical advantage of disc calipers, you can't treat them like rim brakes like that. As the pads wear a little bit, it takes a lot more cable pull to make up the distance.

So barrel adjusters on disc brake cables are only for fine adjustment, and you don't want to be adjusting it with the pinch bolt so much either.

Which is why they have pad adjusters on one or hopefully both sides, and that's where you start when you run out of barrel adjuster.

When there's two adjusters, with the cable disconnected I tighten them up until they're both against the rotor, holding it centrally in the caliper's slot. Then I'll loosen and re-tighten the caliper mounting bolts to ensure it's properly aligned.

Then, feeling the amount of cable pull by working the arm, I loosen the adjusters on each side until there's enough gap for a rotor in half-decent shape not to rub; if the rotor's not in decent shape I tweak it with an adjustable wrench.

Attach cable with all barrel adjusters screwed home, slight adjustment, done.

IMO the pad gap should be enough so that the lever's roughly parallel with the grip when the pads contact.

Last edited by Kimmo; 04-17-14 at 05:09 AM.
Kimmo is offline   Reply With Quote
Old 04-17-14, 08:38 AM   #6
rekon
Senior Member
Thread Starter
 
rekon's Avatar
 
Join Date: Feb 2014
Location: Los Angeles, CA
Bikes: 2015 Cannondale CAAD10; 2014 Giant Talon; 2012 Bianchi Impulso
Posts: 455
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Thanks. So, I loosened the cable clamps, pulled it and clamped it back down. I now have tension in the lever but the brakes are not gripping.
rekon is offline   Reply With Quote
Old 04-17-14, 09:46 AM   #7
rpenmanparker 
Senior Member
 
Join Date: Dec 2009
Location: Houston, TX
Bikes: 1990 Romic Reynolds 531 custom build, Merlin Works CR Ti custom build, super light Workswell 066 custom build
Posts: 19,697
Mentioned: 4 Post(s)
Tagged: 0 Thread(s)
Quoted: 291 Post(s)
I would just slap them while screaming, "Get a grip!"

Just funnin' ya.
__________________
Robert

Quote:
Originally Posted by LAJ View Post
No matter where I go, here I am...
rpenmanparker is online now   Reply With Quote
Old 04-17-14, 10:05 AM   #8
fietsbob 
coprolite
 
fietsbob's Avatar
 
Join Date: Jun 2010
Location: NW,Oregon Coast
Bikes: 7
Posts: 18,851
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 223 Post(s)
You have to look at the gap between the pad and the disc , not what it looks like, standing back .

BB5 fixed pad adjustment, is the knob/Torx on the inside , moving pad the adjustment is the barrel adjuster ..

Or just pulling the cable thru the clamp in the arm further and tightening it there ..


try this: back out the barrel adjuster

pull the cable thru the arm till the pad is against the disc, so wheel wont turn , then tighten it there .

and turn back the barrel adjuster till the wheel moves again..

Last edited by fietsbob; 04-17-14 at 10:10 AM.
fietsbob is online now   Reply With Quote
Old 04-17-14, 10:10 AM   #9
HillRider 
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: 28,776
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 36 Post(s)
Quote:
Originally Posted by rekon View Post
Thanks. So, I loosened the cable clamps, pulled it and clamped it back down. I now have tension in the lever but the brakes are not gripping.
At this point a trip to the LBS seems like a good idea.
HillRider is offline   Reply With Quote
Old 04-17-14, 03:34 PM   #10
rekon
Senior Member
Thread Starter
 
rekon's Avatar
 
Join Date: Feb 2014
Location: Los Angeles, CA
Bikes: 2015 Cannondale CAAD10; 2014 Giant Talon; 2012 Bianchi Impulso
Posts: 455
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by fietsbob View Post
You have to look at the gap between the pad and the disc , not what it looks like, standing back .

BB5 fixed pad adjustment, is the knob/Torx on the inside , moving pad the adjustment is the barrel adjuster ..

Or just pulling the cable thru the clamp in the arm further and tightening it there ..


try this: back out the barrel adjuster

pull the cable thru the arm till the pad is against the disc, so wheel wont turn , then tighten it there .

and turn back the barrel adjuster till the wheel moves again..
This worked! Thank you!
rekon is offline   Reply With Quote
Reply


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 09:00 AM.