urq@audifans.com

[Chuck Pierce]

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[ Picked text/plain from multipart/alternative ]
Jim
I will have to dispute the backwards brake toeing you stated.
In the bike industry we make a point toeing the brake pads to hit with
the leading edge.( approx. 1-2 mm).
When toed flat the brake shoe hits flat and is pulled forward and
chatters, which is the squeal a rider hears.
Reverse toe is for the bike from hell that will not stop squealing
regardless of what you have done.
On cheapo bikes the brakes flex so much that you must put a ton of toe
in as the caliper arms just pull forward and twist a bunch.

Chuck Pierce
91 200tq 20v Avant Slowly getting sorted out
Former owner DeltaFreewheeler Bicycle shop


Jim Haseltine wrote:

>And another reason (well known to pedal cyclists) is to reduce brake squeal.
>If the leading edge of a pad touches first it bites and is then forced away
>slightly by the turning of the braking surface. The pad then skips back and
>bites again only to be forced away again. Result lots of chatter and squeal.
>Take a look at a good quality pedal cycle and you'll find that the brake
>pads are angled slightly so that the trailing edge touches the braking
>surface first. Look at a cheap bike and mostly you'll find that the pads are
>angled any which way and the brakes squeal like a pig when applied. It's
>rare to find a cycle mechanic who isn't well used to twisting brake caliper
>arms.
>
>Regards,
>
>Jim Haseltine
>
>----- Original Message -----
>From: "Todd Phenneger" <tquattroguy at yahoo.com>
>To: "Tony Lum" <tlum at flash.net>; <quattro at audifans.com>
>Sent: Friday, June 20, 2003 7:31 PM
>Subject: Re: urq at audifans.com
>
>
>
>
>>I'm not following why you feel thats not logical.  In ANY multi
>>piston arrangement you always want the smaller piston in front
>>and the larger in back.  IF you do not you will have uneven pad
>>wear across the length of the pad.  You need the extra force at
>>the rear of the bad as the front of the pad has a natural
>>tendency to BITE into the rotor and wear faster.  By increasing
>>the force on the rear of the bad this evens the wear on that
>>pad.
>>  A simplistic example is the old brakes on Pedal Power bikes.
>>I you look at them they almost always wear much faster at the
>>leadign edge because of the tendency for the front to BITE into
>>the surface.
>>  Additionally, you may notice that some pads have a bevel at
>>the front of them to reduce this tendency a little.  Some do
>>not.
>>  Does that answer your question or not?
>>l8r
>>  Todd
>>
>>--- Tony Lum <tlum at flash.net> wrote:
>>
>>
>>>Hi guys,
>>>
>>>The G60 brake caliper has a larger and a smaller piston.  The
>>>smaller
>>>piston is on the leading edge of the rotor with the larger
>>>piston trailing
>>>on the front mounted T44s.  The caliper is rear mounted on the
>>>CQs yet the
>>>smaller piston is still on the leading edge.  Can someone
>>>explain the logic
>>>behind that?
>>>
>>>TIA,
>>>
>>>
>>>
>>>
>>>-Tony
>>>
>>>'80 5KS
>>>83 urquattro #DA900302
>>>'85 4kq
>>>'87 5kcstq
>>>'87.5 coupe GT
>>>
>>>
>>>
>>>
>>__________________________________
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>>
>>
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