Need bike mechanic help

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2009-07-23 3:38 PM

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Champion
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Evergreen, Colorado
Subject: Need bike mechanic help
Okay, so I'm at my parents' house without my Zinn book.  My mom wants me to make her 32 year old bike rideable for her.  It seems okay on everything except the brakes.  They WORK, but they need adjusting.  The back brake requires more squeezing than the front brake which is bad...too much chance of applying too much pressure on the front brake.

Okay, so....I can't figure out how to adjust them.  I took pictures and I was hoping that maybe someone could explain to me how to adjust them.  Here are the photos.  No laughing at the fenders.

2009-07-23 4:21 PM
in reply to: #2304494

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Master
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Subject: RE: Need bike mechanic help

pretty sure u can turn the piece at the end of the grey cable..  the thread below is for adjustment

2009-07-23 4:25 PM
in reply to: #2304572

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Pro
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Bellingham, WA
Subject: RE: Need bike mechanic help
slake707 - 2009-07-23 4:21 PM

pretty sure u can turn the piece at the end of the grey cable..  the thread below is for adjustment



Thats one way to do it and easiest if you can get enough of an adjustment. Two other things to think about would be to replace the brake pads if a lot is worn off of them or loosen the cable and pull a bit more cable than retighten.
2009-07-23 4:28 PM
in reply to: #2304494

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Central NJ
Subject: RE: Need bike mechanic help
Not a Mechanic but, according to my book and if I am seeing the picture correctly you would squeeze the pads against the rim, loosen the cable clamp and then after the slack has been removed, retighten the clamp. A third hand tool would make this easier but it can be done with a web strap or some strong rubber bands. Depending on how tight againt the rim you can get the pads you may want to adjust the adjustment screw to giv some space after the cable adjustment.

you could check the park tool site as well I'm sure they also have the procedure there.
2009-07-23 4:30 PM
in reply to: #2304494

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Extreme Veteran
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Buford GA
Subject: RE: Need bike mechanic help
you need to turn the knurled barel out, loosen it in regards to direction to turn. This is essentially lengthening the housing which then shortens the cable like you were pulling the lever. Afterwards you back down the lock nut back to where it is so it stays in place.

You can't loosen up the fronts at all based on those pics so tighten tightening the rears is all you can do.

If that doesn't get you enough before the rears are touching the rims you'll need to actually loosen the front cable to get more slack.

Due to the length of cables front vs rear this is almost always how bikes are going to be especially on much older brakes that may not be front and rear specific so not equipped with springs to compensate or having spring adjusment to the brakes themselves.

I'd really really suggest new brake pads as those are going to be dry and brittle and may even fail.

Edited by mrtopher1980 2009-07-23 4:31 PM
2009-07-23 4:30 PM
in reply to: #2304572

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Sensei
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Subject: RE: Need bike mechanic help

Wow!  Old brakes...

Anyway, the nut and the silver thing with the grooves are seperate, but as I recall, sometimes they get tightened up so close to each other, that they sort of fuse together and lock up against the brake.  I think you can get some pliers and turn the grooved counter clockwise to get the pads closer to the rims.  Once they are adjusted, turn the nut down flush to the brake.

It looks like the entire thing as been adjusted to the max and the adjuster is right up to the nut.

If messing with the adjuster doesn't do a good enough job, you may need to loosen or tighten the cable, with is cinched with the other nut at the end of the calipar.

Make any sense?

2009-07-23 5:20 PM
in reply to: #2304494

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Champion
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Evergreen, Colorado
Subject: RE: Need bike mechanic help
Hmm...I don't suppose any of you could tell me which nut, etc. you're talking about?  I am not so mechanically inclined and I am not sure which ones you are talking about.  Maybe refer by picture number and location (i.e. second picture, first nut on the left)?

I am tempted to break down and find a bike shop tomorrow.....
2009-07-23 6:22 PM
in reply to: #2304494

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Central NJ
Subject: RE: Need bike mechanic help
Third picture nut on back of upper right bolt. Where in Jersey are you there are some decent bike shops around here.
2009-07-23 6:36 PM
in reply to: #2304494

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Buford GA
Subject: RE: Need bike mechanic help



excuse the crude arrows did it quick in paint

the blue arrow is the main adjuster. the green arrow is the lock nut

turning that adjster so it backs out (loosening) will tighten the rear brakes, once you have the tension set then just back the lock nut down against the brake caliper basically where it is now.. this would be turning it in the opposite direction you did the main adjuster.

If that doesn't tighten up the back enough before you get the brakes to match and the pads end up against the rim then you'll need to actually adjust the cable on the front so that it has more slack. this would be done by loosening the nut that the cable is going through no the adjuster. you wll need to hold the brake pads against the rim or close when you loose and then tighten the cable. this is not super advanced but at that point may need to go to a bike shop if you need explanation on how to adjust the other part (sorry if that came of mean just being honest)
2009-07-23 6:38 PM
in reply to: #2304494

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Master
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Cypress, CA
Subject: RE: Need bike mechanic help

I'd start by replacing the brake pads just on principle.  It looks like they're pretty old, and even if they still have plenty of pad left, they've probably hardened up some and aren't as effective as they need to be.  Also clean up the braking surface on the rim.  And think about replacing the cables as well.

As for adjustment, these are really just like modern brakes.  I think you need to do the following:

  • Loosen the nut clamping the end of the cable wire (the one on the bottom on the front brake, at the top on the rear)
  • Replace the brake pads while the cable is loose
  • Optional--Back the barrel adjuster (the knurled knob next to the cable housing) out a few turns so that you can adjust in either direction.  But most of your adjustment will be backing it out (tightening the cable) as the pads wear, so leave most of it in.  Tighten the lock nut below the knurled knob so it stays in position.
  • With your hand, press the brake pads in against the rim.
  • Pull the brake cable taut and tighten up the nut that holds it (the one you loosened in the first step).  Note that now you have one hand pulling the wire, another one wrenching the nut, and a third one holding the brake pads to the rim--you may need a buddy for this.
  • Usually even if you try to pull it pretty tight, there is still enough slack in the cable that when you stop holding the brake pads against the rim, they back out a couple of mm so they're sufficiently tight but not rubbing on the rim.  If they're too tight, either screw the barrel adjuster in if you can or repeat the  process and leave the cable a little looser.
  • You might need to fiddle with adjustment of the front and rear to get them about even in tension.  Try to get the pads about the same distance out from the rim and you should be good to go.
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