Shimano brake alignment problem

[Derk Drukker]

Hi!

I just changed a brake on my bike (from Ultegra->D-A) and one the new brake's parts that holds 1 of
the brake shoes (is that en existing word? no idea what that's called in English) was tilted a bit,
so that the rubber didn't touch the rim over the full length. I spoke to a friend of mine who is a
cycling mechanic and he told me that at his work a wrench is used to bend the brake into shape
again. "Aligning the brake" he calls it.

According to him, abaout 10% of all brakes are not perfect when they get out of the box and must
therefore "be aligned".

Anyone else who knows this problem?

Greets, Derk

 

[Patrick Welch]

"Derk Drukker" <[email protected]> wrote in message
news[email protected]...
> Hi!
>
> I just changed a brake on my bike (from Ultegra->D-A) and one the new
brake's
> parts that holds 1 of the brake shoes (is that en existing word? no idea
what
> that's called in English) was tilted a bit, so that the rubber didn't touch the rim over the full
> length. I spoke to a friend of mine who is a cycling mechanic and he told me that at his work a
> wrench is used to bend the brake into shape again. "Aligning the brake" he calls it.
>
> According to him, abaout 10% of all brakes are not perfect when they get out of the box and must
> therefore "be aligned".
>
> Anyone else who knows this problem?
>
> Greets, Derk

I had to bend the calipers on an old set of Campy Chorus brakes in order to correctly align them
(called toe-in in English!). I've never used Dura-Ace, but most newer brake pads have conical
washers which allow you to adjust the angle of the pad without bending the calipers. Are you sure
you can't adjust them w/o bending? I would only do that as a last resort.

-Patrick

 

[Mike Krueger]

<< I just changed a brake on my bike (from Ultegra->D-A) and one the new brake's parts that holds 1
of the brake shoes (is that en existing word? no idea what that's called in English) was tilted a
bit, so that the rubber didn't touch the rim over the full length. I spoke to a friend of mine who
is a cycling mechanic and he told me that at his work a wrench is used to bend the brake into shape
again. "Aligning the brake" he calls it. According to him, abaout 10% of all brakes are not perfect
when they get out of the box and must therefore "be aligned". Anyone else who knows this problem? >>

It's called "toe-in", and what you want it for the front edge of the brake pad to make contact with
the rim first, which pulls the rest of the pad against the rim as the brake arm flexes. This also
reduces squealing. I wouldn't go so far as to try to permanently bend the break arm. You might
damage something. Instead, you can sand down the trailing edge of the rubber brake pad with emery
paper, forcing the front edge to contact the rim first. Or, you can upgrade to the aftermarket brake
shoes for Dura Ace made by Kool-Stop, which have a toe-in adjustment on the mounting bolt.
Otherwise, it's not that big of a deal, and the pads will wear into position eventually by
themselves.

 

[H. Van Beek]

My Dura Ace brakes were not well aligned when I bought my bike secondhand. My LBS has aligned them
perfectly now. It happens to be that there is a special tool to bend the brakearms of Shimanobrakes.

"Mike Krueger" <[email protected]> schreef in bericht
news:[email protected]...
> << I just changed a brake on my bike (from Ultegra->D-A) and one the new brake's parts that holds
> 1 of the brake shoes (is that en existing word? no idea
what
> that's called in English) was tilted a bit, so that the rubber didn't touch the rim over the full
> length. I spoke to a friend of mine who is a cycling mechanic and he told me that at his work a
> wrench is used to bend the brake into shape again. "Aligning the brake" he calls it. According to
> him, abaout 10% of all brakes are not perfect when they get out of the box and must therefore "be
> aligned". Anyone else who knows this problem? >>
>
> It's called "toe-in", and what you want it for the front edge of the brake
pad
> to make contact with the rim first, which pulls the rest of the pad
against the
> rim as the brake arm flexes. This also reduces squealing. I wouldn't go so far as to try to
> permanently bend the break arm. You
might
> damage something. Instead, you can sand down the trailing edge of the
rubber
> brake pad with emery paper, forcing the front edge to contact the rim
first.
> Or, you can upgrade to the aftermarket brake shoes for Dura Ace made by Kool-Stop, which have a
> toe-in adjustment on the mounting bolt. Otherwise,
it's
> not that big of a deal, and the pads will wear into position eventually by themselves.