brake pads are wider than braking surface

[Michael]

I've got threaded Delta Aztec brake pads in my Ultegra brakes on my Cannondale road bike with
(currently) Spinergy Spox wheels and (previously) Mavic Open Pro/Ultegra wheelset.

The pads appear mounted correctly, in that the top of the pad meets the top/outer diameter of the
rim braking surface area exactly. But the pads are about 2mm wider than the machined braking surface
on the wheels, meaning the bottom 2mm of pad doesn't contact the rim braking surface.

So as the pads wear, a lip of un-worn-pad develops on the bottom of the pad, and the lip rubs the
inner/side portion of the rim. This has worn away some of the stickers on the rim. I have to file
down the lip periodically.

Why would the pad be wider than the braking surface it mates with? Does the lip contacting the inner
portion of the rim during hard braking present any problem? It seems like as the pad wears, the lip
would start contacting the rim before the rest of the pad, possibly INSTEAD of the rest of the pad,
dramatically decreasing braking power.

 

[S. Anderson]

"Michael" <[email protected]> wrote in message
news:[email protected]...
> I've got threaded Delta Aztec brake pads in my Ultegra brakes on my Cannondale road bike with
> (currently) Spinergy Spox wheels and (previously) Mavic Open Pro/Ultegra wheelset.

<<snip..>>

> Why would the pad be wider than the braking surface it mates with? Does the lip contacting the
> inner portion of the rim during hard braking present any problem? It seems like as the pad wears,
> the lip would start contacting the rim before the rest of the pad, possibly INSTEAD of the rest of
> the pad, dramatically decreasing braking power.

Bicycle brakes are not exactly precision instruments. There are many different types of rims, pads
and brakes. The extra bit of brake pad doesn't really matter. It won't affect braking performance
significantly but it will wear parts of the rim outside the intended braking area. Find some
narrower pads or make with the file. Your choice.

Cheers,

Scott..

 

[Paul Southworth]

In article <[email protected]>, Michael
<[email protected]> wrote:
>I've got threaded Delta Aztec brake pads in my Ultegra brakes on my Cannondale road bike with
>(currently) Spinergy Spox wheels and (previously) Mavic Open Pro/Ultegra wheelset.
>
>The pads appear mounted correctly, in that the top of the pad meets the top/outer diameter of the
>rim braking surface area exactly. But the pads are about 2mm wider than the machined braking
>surface on the wheels, meaning the bottom 2mm of pad doesn't contact the rim braking surface.
>
>So as the pads wear, a lip of un-worn-pad develops on the bottom of the pad, and the lip rubs the
>inner/side portion of the rim. This has worn away some of the stickers on the rim. I have to file
>down the lip periodically.
>
>Why would the pad be wider than the braking surface it mates with?

Mfr apparently didn't anticipate how wide your braking surface
is.

>Does the lip contacting the inner portion of the rim during hard braking present any problem? It
>seems like as the pad wears, the lip would start contacting the rim before the rest of the pad,
>possibly INSTEAD of the rest of the pad, dramatically decreasing braking power.

No, when you clamp that brake lever, the lip will be crushed and the face of the pad will
meet the rim.

Consider removing the pads and trimming the bottom (the part facing the ground) with a utility knife
so that the pad is a little narrower where it meets the rim.

--Paul