springbreak breakspring

Jose Capco said:

Dear NG,

Ok let me get to the point. I left my bike out for a week or so, when it
was snowing. Then I decided to bring it back home, so I went out and
biked back home.. everything was ok. Then I left it in the garage for
another week. The next time I wanted to bike it, I realized that the
breaks were not responding very well. Next day I examined the bike and
saw that the breakspring do not work properly. Whenever I press on the
break handle and release it, then the breaks are supposed to release the
tire but this happens only on one side of the break (the spring of the
right break of the rear tire coils back but that of the left break does
not).

So I took the Allen screw and dissassembled the breaks of the rear tire.
I thought maybe the bad weather has caused the spring to reach its
elastic limit (or whatever..). When I took out the spring it didnt
looked broken I couldnt coil it with bare hands.. so I really dont know
if this is really the defect part. I only know that when I screw the
breaks back untightly then the spring acts on it (not very well but at
least the break returns a few milimeters when I release the breaks) but
its still not very good. I dont want to buy a new spring (Im not even
sure if they sell that part of the break only) if this is not the
problem. Could someone advise?

Sincerely,
Jose Capco

These guys explain it better than I can.

http://www.parktool.com/repair_help/FAQindex.shtml#brakes

Ron

Jose Capco said:

Dear NG,

Ok let me get to the point. I left my bike out for a week or so, when it
was snowing. Then I decided to bring it back home, so I went out and
biked back home.. everything was ok. Then I left it in the garage for
another week. The next time I wanted to bike it, I realized that the
breaks were not responding very well. Next day I examined the bike and
saw that the breakspring do not work properly. Whenever I press on the
break handle and release it, then the breaks are supposed to release the
tire but this happens only on one side of the break (the spring of the
right break of the rear tire coils back but that of the left break does
not).

So I took the Allen screw and dissassembled the breaks of the rear tire.
I thought maybe the bad weather has caused the spring to reach its
elastic limit (or whatever..). When I took out the spring it didnt
looked broken I couldnt coil it with bare hands.. so I really dont know
if this is really the defect part. I only know that when I screw the
breaks back untightly then the spring acts on it (not very well but at
least the break returns a few milimeters when I release the breaks) but
its still not very good. I dont want to buy a new spring (Im not even
sure if they sell that part of the break only) if this is not the
problem. Could someone advise?

Sincerely,
Jose Capco

Probably the spring is acting with as much force as it ever did, but the
cantilever has been contaminated by grit and now the spring is pushing
against a lot of friction.

Since you already know how to take apart the cantilever assembly, the
best thing to try would be to thoughroughly clean the whole shebang,
with special attention to the bushing where two parts slide over each
other. Then put it all back together with a good amount of grease, which
will lubricate and act as a seal against bad weather in the future.

Jose Capco asked:

Quoted message said:

Could someone advise?

LUBE

Jose Capco said:

Dear NG,

Ok let me get to the point. I left my bike out for a week or so, when
it was snowing. Then I decided to bring it back home, so I went out
and biked back home.. everything was ok. Then I left it in the garage
for another week. The next time I wanted to bike it, I realized that
the breaks were not responding very well. Next day I examined the
bike and saw that the breakspring do not work properly. Whenever I
press on the break handle and release it, then the breaks are
supposed to release the tire but this happens only on one side of the
break (the spring of the right break of the rear tire coils back but
that of the left break does not).

So I took the Allen screw and dissassembled the breaks of the rear
tire. I thought maybe the bad weather has caused the spring to reach
its elastic limit (or whatever..). When I took out the spring it didnt
looked broken I couldnt coil it with bare hands.. so I really dont
know if this is really the defect part. I only know that when I screw
the breaks back untightly then the spring acts on it (not very well
but at least the break returns a few milimeters when I release the
breaks) but its still not very good. I dont want to buy a new spring
(Im not even sure if they sell that part of the break only) if this
is not the problem. Could someone advise?

Yes. Be nice to your neighbors, lest one of them report you to the SPCB.

Jose Capco said:

Ok let me get to the point. I left my bike out for a week or so, when it
was snowing. Then I decided to bring it back home, so I went out and
biked back home.. everything was ok. Then I left it in the garage for
another week. The next time I wanted to bike it, I realized that the
breaks were not responding very well. Next day I examined the bike and
saw that the breakspring do not work properly. Whenever I press on the
break handle and release it, then the breaks are supposed to release the
tire but this happens only on one side of the break (the spring of the
right break of the rear tire coils back but that of the left break does
not).

So I took the Allen screw and dissassembled the breaks of the rear tire.
I thought maybe the bad weather has caused the spring to reach its
elastic limit (or whatever..). When I took out the spring it didnt
looked broken I couldnt coil it with bare hands.. so I really dont know
if this is really the defect part. I only know that when I screw the
breaks back untightly then the spring acts on it (not very well but at
least the break returns a few milimeters when I release the breaks) but
its still not very good. I dont want to buy a new spring (Im not even
sure if they sell that part of the break only) if this is not the
problem. Could someone advise?

You do not have a spring problem. You have a corrosion
problem in your brake or cable or both.

--
Andrew Muzi
www.yellowjersey.org
Open every day since 1 April, 1971

A Muzi said:

You do not have a spring problem. You have a corrosion problem in your
brake or cable or both.

do you also mean that I need to lubricate? What has corrosion to do with
a break that doesnt release a grip on the tire? I'll lubricate and
report. Thanks!

A Muzi said:

Quoted message said:

You do not have a spring problem. You have a corrosion problem in your
brake or cable or both.

Quoted message said:

Quoted message said:

Jose Capco wrote:

Quoted message said:

do you also mean that I need to lubricate? What has corrosion to do with
a break [sic] that doesnt release a grip on the tire? I'll lubricate and
report. Thanks!

The spring is only so strong. When there's excessive friction in the
mechanism, the spring's normal strength isn't sufficient to overcome the
friction and return the arm to its rest position.

Andy's right.

Try unhooking the cable and see if both arms move equally freely. If
one of them is stiffer than the other, you need to lubricate its pivots.

While the cable is disconnected, try manually working it in and out, see
if _it_ is sliding freely. Most likely it isn't. If the cable is
rusted up, it may be possible to disassemble and grease it, or you may
need to replace it. If you need new cables, get stainles steel ones
next time.

See: http://sheldonbrown.com/canti-direct.html

and: http://harriscyclery.com/cables

Sheldon "Stop!" Brown
+----------------------------------------+
| The art of being wise is the art of |
| knowing what to overlook. |
| --William James |
+----------------------------------------+
Harris Cyclery, West Newton, Massachusetts
Phone 617-244-9772 FAX 617-244-1041
http://harriscyclery.com
Hard-to-find parts shipped Worldwide
http://captainbike.com http://sheldonbrown.com

Quoted message said:

Quoted message said:

A Muzi wrote:
You do not have a spring problem. You have a corrosion problem in your
brake or cable or both.

Jose Capco said:

do you also mean that I need to lubricate? What has corrosion to do with
a break that doesnt release a grip on the tire? I'll lubricate and
report. Thanks!

Yes. Undo the cable from a stop on the frame. ( don't use a
wrench) and pull back the casing to show the wire. Is it
rusted? Oil or grease.

With the cable not connected, will both sides of the brake
snap back smartly? If not, see if the brake pivot is rusted.
On linear ("V"😉 brakes that pivot can be difficult to access
on some models. Write back if so.

Lastly, look at the surface of your brake shoe which touches
the rim. Is it flat? When a shoe wears with a small lip at
the bottom, it will stick. Trim such a ridge away with a blade.

--
Andrew Muzi
www.yellowjersey.org
Open every day since 1 April, 1971

Jose Capco said:

OK let me get to the point. I left my bike out for a week or so,
when it was snowing. Then I decided to bring it back home, so I
went out and biked back home... everything was OK. Then I left it
in the garage for another week. The next time I wanted to bike it,
I realized that the breaks were not responding very well. Next day
I examined the bike and saw that the break spring does not work
properly. Whenever I press on the break handle and release it, then
the breaks are supposed to release the tire but this happens only on
one side of the break (the spring of the right break of the rear
tire coils back but that of the left break does not).

It would be good to know what sort of brake caliper this is. From
what you say, this is not a dual pivot brake because these brakes were
designed to overcome this problem, that of the friction induced,
non-centered brake. Traditional single pivot brakes have a caliper
ratio of 1:1, cable motion to pad motion. Because this ratio was to
low a mechanical advantage to people without an athletic grip, a 35%
higher ration was selected, one which required lower pad clearance.
For lower pad clearance, forced centering was required and that's why
we have dual pivot brakes that cannot go off center.

The return spring of a caliper slides on two nubbins on the caliper
arms that are exposed to weather and dirt. Symmetric contamination is
rare, so these brakes easily go off center. To fix this, lubricate
the spring contact at the caliper arms (with motor oil) and pump the
brake holding one pad against the rim while the other articulates and
then repeat the procedure, holding the other pad against the rim.
This usually gets the brake on center. Changing the caliper position
in rotation, the usual fix, does not help for long. I have watched
bicycle shops do this for years and it's hard to tell the mechanic
what's going on in front of customers.

Try it and let us know what you find.

Jobst Brandt
[email hidden]