Topica Loopframe_Guzzi Archive


Subject: Re: Brake question

Author: Jay Williams

Date: May 4, 2001, 7:33 AM

Post ID: 1706591343


I had the exact problem when I redid the brakes on my '71 Ambo.
So far as I can tell, here's the deal:
After 25 years or so, the drums will have worn slightly where the old pads
have rubbed aginst their inner diameter.
Due to manufacturing tolerances, the replacement pads don't run in exactly
the same "groove" as the old pads, (or made be made fractionally wider.)
Upon brake application, only that portion of the brake pad outside the
groove will make contact, and that interference causes the rest of the brake
lining to be "suspended" above the drum surface.
The small portion of the pad that actually contacts the drum is enough to
cause drag, but prevents enough surface area contact between the brake shoe
and drum to stop the bike in a reasonable fashion.
The proper solution is to have the drum turned. But I couldn't find anyone
locally who could do the job unless I dissasembled it from the rim. Not
being anxious to do that, my alternative solution was to chamfer the edges
of the bake pads with a hand file. That allowed the shoe to drop into the
already worn drum surface. I didn't take off much material, but it worked.
Braking improved 300%, at least, and I was able to adjust the cable to get
full application of the brake before the lever hits the handlebar. Still
doesn't stop like a good set of discs, but certainly adequate and no longer
scary.

Jay Williams


Hi All,

I have a question relating to the front brake on my 69 and 70 Ambos.

Both brakes are solid with good drums and lots of pad (4mm out of 5mm).

My problem is that when I adjust the brake so that the pad is just about to
touch the drum in free wheel (brake off) then I don't have enough lever pull
to get the brakes to fully grab. What I mean by that is that when I squeeze
the lever I get to the end (hits the handlebar) before I get maximum
braking.

I was practicing this yesterday. At 20-30mph I was pulling the front brake
to max. I just can't get the braking performance I want. It's kind of like a
1960's antilock braking system :-)

Any suggestions as to what I can do to get the cable/lever tightened up so I
can get all the pull I want? Anyone else experience this? I guess I could
always tighten up the cable play but that would mean the drums would be
rubbing on the pads during free wheel.

Thanks....Ian





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