What makes my brakes soooo noisy?

Just acquired a 12 speed racer (FAlcon) in decent nick - looks quite new. Brake blocks also look
new-ish, not much wear.

Front isnt too bad but back brakes make a deafening squeal and are also a bit "grabby" - its quite
easy to lock the wheel.

Any idea what would cause this?

RC

 

"CLogicRogerC" <[email protected]> wrote in message
news:[email protected]...
> Just acquired a 12 speed racer (FAlcon) in decent nick - looks quite new.
Brake
> blocks also look new-ish, not much wear.
>
> Front isnt too bad but back brakes make a deafening squeal and are also a
bit
> "grabby" - its quite easy to lock the wheel.
>
> Any idea what would cause this?

Have you got the toe in right?

 

Toe out. Brake blocks should be toe-in. i.e. the front should hit rim first.

 

On 13 Jan 2003 20:01:50 GMT, CLogicRogerC <[email protected]> wrote:
> Just acquired a 12 speed racer (FAlcon) in decent nick - looks quite new. Brake blocks also look
> new-ish, not much wear.
>
> Front isnt too bad but back brakes make a deafening squeal and are also a bit "grabby" - its quite
> easy to lock the wheel.
>
> Any idea what would cause this?

Check the alignment and toe-in of the pads, perhaps give them and the rims a clean too. See
http://www.parktool.com/repair_help/howfix_linearbrakes.shtml

As for the grabbiness, hmm. If the barrel adjuster doesn't do anything, and it feels like
something's getting stuck or held up somewhere, unhook the cable at both ends briefly, and make
sure that it moves smoothly through the sleeve and that the lever and the brake arms move cleanly.
Clean and grease the bits that don't. If it's not that, then perhaps setting the blocks a bit
wider by switching the bolt washers around or fiddling with the nut that holds it in place might
do the trick.

--
Andrew Chadwick bicycle is just one of many bicycles in the world bicycle is little wings

 

Most likely to be lubricant (WD40 or similar) on the rims - try cleaning the rims with Muck Off or
washing up liquid, scrub and rinse off well - may be worth cleaning the surface of the brake pads
with some fine sandpaper.

If that doen't fix the problem check that the rim is round and true and that the blocks are striking
the rim squarely and at the same time.

It is also worth checking that the brake is firmly anchored to the frame and that the pivot bolts
are not loose.

Hope this helps.

John

[email protected] (CLogicRogerC) wrote in message
news:<[email protected]>...
> Just acquired a 12 speed racer (FAlcon) in decent nick - looks quite new. Brake blocks also look
> new-ish, not much wear.
>
> Front isnt too bad but back brakes make a deafening squeal and are also a bit "grabby" - its quite
> easy to lock the wheel.
>
> Any idea what would cause this?
>
> RC

 

CLogicRogerC wrote:
> Front isnt too bad but back brakes make a deafening squeal and are also a bit "grabby" - its quite
> easy to lock the wheel.
>
> Any idea what would cause this?

If not oil, etc, it's the British winter: moisture from air or road ends up on rims and brakes.

Adjusting brakes can help sometimes (and check everything's tight), but it's not possible to toe-in
with some models. Clean rim and blocks with meths and lightly sand blocks. Brakes may be even more
grabby at first after this treatment, but should soon settle down. If still no better after a while,
try a different brand of brake blocks. The problem can't always be cured without changing the rim
or/and brake caliper, so use ear plugs until the summer

Anyway, use the front brake more, back less. See: http://www.sheldonbrown.com/brakturn.html

~PB

 

> Just acquired a 12 speed racer (FAlcon) in decent nick - looks quite new. Brake blocks also look
> new-ish, not much wear.
>
> Front isnt too bad but back brakes make a deafening squeal and are also a bit "grabby" - its quite
> easy to lock the wheel.
>

Don't ever change it - that's the only noise that gets pedestrians to pay attention.

Angle of the brake shoes is the generally quoted cause, but my bike sometimes starts to squeak if
just left in the garage for a few days without being ridden.

Jeremy Parker

 

The message <[email protected]> from [email protected] (CLogicRogerC)
contains these words:

> Any idea what would cause this?

No, but it usually responds to swapping front brake blocks with rear ones.

--
Helen D. Vecht: [email protected] Edgware.

 

"CLogicRogerC" <[email protected]> wrote in message
news:[email protected]...
> Just acquired a 12 speed racer (FAlcon) in decent nick - looks quite new.
Brake
> blocks also look new-ish, not much wear.
>
> Front isnt too bad but back brakes make a deafening squeal and are also a
bit
> "grabby" - its quite easy to lock the wheel.
>
> Any idea what would cause this?
>
> RC
If these are Weinmann centre pulls then the grabbiness in the rear may be caused by the nut which
fastens the brake to the frame becoming loose. This causes a sort of servo effect. When you apply
the brake the rim pulls the brake forward, rotating it around the brake bridge, and so moving it
away from the hanger and applying the brake more. This is alarmingly grabby. Mike Sales

 

"Gearóid Ó Laoi, Garry Lee" <[email protected]> wrote in message
news:[email protected]...
> Toe out. Brake blocks should be toe-in. i.e. the front should hit rim first.
>
>
...or, possibly, like mine (Raleigh Sun Solo), pads with leather inserts. I believe the idea behind
this was to allow for greater grip on steel rims in wet weather. Doesn't work brilliantly but is a
very effective warning of approach, so I've left 'em in ;-) Dave.

 

[email protected] (John Prady) wrote in message
news:<[email protected]>...
> Most likely to be lubricant (WD40 or similar) on the rims - try cleaning the rims with Muck Off or
> washing up liquid, scrub and rinse off well

From my own experiences with oil, grease, etc. on the braking surface of the rim, chrome polish
(Halfords, Weldtite, or similar [1]) works a treat for alloy wheels.

David E. Belcher

Dept. of Chemistry, University of York

[1] Effective products, with an easily applied toothpaste-style consistency. Shame about the smell
(think ammonia/old fish/low-quality public loos), though....

 

Jeremy Parker <[email protected]> said:
>> Just acquired a 12 speed racer (FAlcon) in decent nick - looks quite new. Brake blocks also look
>> new-ish, not much wear.
>>
>> Front isnt too bad but back brakes make a deafening squeal and are also a bit "grabby" - its
>> quite easy to lock the wheel.
>>
>
> Don't ever change it - that's the only noise that gets pedestrians to pay attention.

Mmm, that reminds me. Does anyone have any suggestions for bells and hooters suitable for drop bar
bikes with already crammed handlebar tops (light, computer, extra reflector etc)? Ideally this would
be something that screwed in place of a bar-end cap but I'm open to other suggestions. Currently my
method of warning errant pedestrians of my approach is something like "Oi, you!" (politely
paraphrased) which isn't massively effective.

Note that the frame doesn't have mountings for anything at all, not even mudguard eyes or a bottle
cage so battery powered horns are probably out.

Regards,

-david

 

<snip>
> > Front isnt too bad but back brakes make a deafening squeal and are also
a bit <snip>

I know, I know......carefully remove mice from between brake blocks and rims.....(Mice are renowned
for sneaking into undisturbed tight spaces to winter over. No doubt this bike had been 'put to one
side' for a period of time, prior to you purchasing it - hence the mice ! ) HTH, Dave. ;-)

 

David Nutter wrote:
> Mmm, that reminds me. Does anyone have any suggestions for bells and hooters suitable for drop bar
> bikes with already crammed handlebar tops (light, computer, extra reflector etc)?

There are neat little Japanese bells whch clamp onto side of handlebar stem (sorry, can't remember
any more about them at the moment).

> Note that the frame doesn't have mountings for anything at all, not even mudguard eyes or a bottle
> cage so battery powered horns are probably out.

No, those things called brackets and nuts and bolts help ;-)

~PB

 

On Tue, 14 Jan 2003 12:02:52 +0000 (UTC), David Nutter <[email protected]> wrote:
> Jeremy Parker <[email protected]> said:
>>> Just acquired a 12 speed racer (FAlcon) in decent nick - looks quite new. Brake blocks also look
>>> new-ish, not much wear.
>>>
>>> Front isnt too bad but back brakes make a deafening squeal [...]
>>
>> Don't ever change it - that's the only noise that gets pedestrians to pay attention.
>
> Mmm, that reminds me. Does anyone have any suggestions for bells and hooters suitable for drop bar
> bikes with already crammed handlebar tops (light, computer, extra reflector etc)? Ideally this
> would be something that screwed in place of a bar-end cap but I'm open to other suggestions.

There's a pingy bell made by Mirrycle that can be mounted to bar ends:
<http://www.mirrycle.com/barend.htm>. Biketrax in Edinburgh seem to be flogging them in their online
sale: http://www.biketrax.co.uk/infopage/homepage/6ce098364b1876559888432ac47a11a2/

> Currently my method of warning errant pedestrians of my approach is something like "Oi, you!"
> (politely paraphrased) which isn't massively effective.

Yelling or sounding something that obviously sounds like a bike bell is probably best, at low speed.
Horns don't exactly say "bike", and I'm not sure ping-bells are much good either.

> Note that the frame doesn't have mountings for anything at all, not even mudguard eyes or a bottle
> cage so battery powered horns are probably out.

The Air Zound with the bottle strapped somewhere convenient, if there's one left. Should get a ped's
attention, but dim ones might just stop in your way to gawp at you while their brain catches up.

Though I wonder if something odd, hacky and similarly loud could be put together using an old inner
tube threaded through the frame, perhaps in the handlebars themselves with the valve sticking out of
one end cap and a horn bit out of the other. I don't know how much air can be got into the Zound or
how many blasts can be got out of it, unfortunately.

--
Andrew Chadwick <Secure beneath the watchful eyes

 

Thanks to all that replied re noisy brakes - when I get home I'll re-align, tighten and lubricate
everything, try to toe-in the blocks (though I have a feeling that these particular blocks just come
in at 90 degrees whichever way round you put them), then sand down the blocks and clean the rims
with washing up liquid.

Lets see if that does the trick!

Cheers again for the advice folks.

RC

 

"CLogicRogerC" <[email protected]> wrote in message
news:[email protected]...
> Thanks to all that replied re noisy brakes - when I get home I'll
re-align,
> tighten and lubricate everything, try to toe-in the blocks (though I have
a
> feeling that these particular blocks just come in at 90 degrees whichever
way
> round you put them), then sand down the blocks and clean the rims with
washing
> up liquid.
>

The brake fittings themselves allow you to toe-in the blocks.

 

CLogicRogerC <[email protected]> said:
> Thanks to all that replied re noisy brakes - when I get home I'll re-align, tighten and lubricate
> everything, try to toe-in the blocks (though I have a feeling that these particular blocks just
> come in at 90 degrees whichever way round you put them),

The nuclear solution is to bend the caliper arms if you can to adjust the toe (recommended only if
the caliper is a cheap kind that you don't mind breaking), or shape the pads to have the appropriate
toe. More expensive calipers should have the ability to adjust the toe anyway.

I re-toed the right arm of my front caliper (single pivot One Lucky Fish Bicycle Company job) on my
hack bike using this method, but that was to make sure more of the pad contacted the rim rather than
your problem.

Regards,

-david

 

The message <[email protected]> from "elyob" <[email protected]>
contains these words:

> >

> The brake fittings themselves allow you to toe-in the blocks.

I don't think Weinmann centrepulls etc do. Cantilever brakes are a different story...

--
Helen D. Vecht: [email protected] Edgware.

 

Helen Deborah Vecht scribed after much navel searching:
> The message <[email protected]> from "elyob"
> <[email protected]> contains these words:
>
>
>
>>The brake fittings themselves allow you to toe-in the blocks.
>
>
> I don't think Weinmann centrepulls etc do. Cantilever brakes are a different story...
>
No they don't - you have to bend the caliper arm.......