Re: [CR]Bushings on centerpulls

(Example: Events:Cirque du Cyclisme:2007)

To: "James A Narlesky" <jim@alandavid.com>, <RaleighPro531@aol.com>, <classicrendezvous@bikelist.org>
Date: Wed, 13 Mar 2002 17:24:20 -0500
From: <BILL_BRYANT@prodigy.net>
Subject: Re: [CR]Bushings on centerpulls

Yes, they aren't that hard to make, in fact rather simple. Lacking production machinery, they're just time-consuming. After we ran out of production "brake boosters" at Cupertino Bike Shop, we made a few more by hand from 1/8" or 3/16" aluminium plate. Sometimes we got creative with the shapes and did some special artwork to jazz things up on otherwise pedestrian brake sets. (The booster plate with a small Bernard Hinault portrait that went on the bike of a Peugeot amateur team racer traveling to France in 1981 was my personal favorite. Hopefully "The Badger" motif brought the rider good luck and iron nerves in the peloton.)

It was tedious grunt work carving out the shapes, but as you say, the booster plates really improved the braking performance of the plastic-bushing Mafac Racers and other center-pulls by keeping the pivot points parallel under hard braking force from the handle & cable. Often we just put the booster plates on the front brake since equally hard braking on the rear locked up the wheel. Combined with some better brake pads, like Mathausers, this generally brought things up to par with the fancy Mafac Criteriums (?-- if I recall the name correctly/) center-pulls that had the posts brazed onto the frame. Mostly, though, in those days using Campy sidepulls was a better overall equipment choice unless there was some overriding reason to use center-pulls (such as team sponsorship).

Bill "one last pair of boosters in the vault" Bryant Santa Cruz, CA


--- Original Message ---
From: James A Narlesky
To: RaleighPro531@aol.com

<classicrendezvous@bikelist.org> Subject: Re: [CR]Bushings on centerpulls
>Peter, Jan, et al.
>
>For Mafac brakes, the after market arched plate that connected just in front
>of the bushings really makes a notable improvement in the feel and
>modulation of these particular brakes. This fix limits the flex of the
>calipers considerably. If someone were to make more of these there would not
>be the perceived need for bronze bushings and I would bet that these arched
>devices would be easier to make.
>
>Regards,
>
>Jim "Accountant, not a Machinist"Narlesky
>San Jose, CA
>----- Original Message -----
>From: <RaleighPro531@aol.com>
>To: <classicrendezvous@bikelist.org>
>Sent: Wednesday, March 13, 2002 11:32 AM
>Subject: Re: [CR]Bushings on centerpulls
>
>
>> In a message dated 3/13/2002 2:15:23 PM Eastern Standard Time,
>> heine@mindspring.com writes:
>>
>>
>> > The plastic bushings on the Mafacs could be replaced easily. Hardware
>> > stores have bushings, but the right size might be harder to find.
>> > I've been thinking of machining the bushings - and they are bronze,
>> > not brass, as far as I know (and so are the ones in the hardware
>> > store). I haven't got around to it. Anybody interested? I can provide
>> > specs.
>> >
>> > HOWEVER, the brakes work great even with plastic bushings, so I
>> > haven't felt the need. Consider than the bearing surface on the large
>> > pivots is much greater than the pivot bolt on a standard sidepull
>> > (such as Campy NR), and even those don't seem to be a problem.
>>
>> My interest in doing new bushings would be to make the pivots a bit
>tighter
>> so as to limit arm movement under braking.
>> Maybe it's a moot point anyway: if the pivots are tight then the arms flex
>> enough to make it more trouble than it's worth?
>>
>> Pete Geurds
>> Douglassville, PA
>>
>>
>> _______________________________________________
>> Classicrendezvous mailing list
>> Classicrendezvous@bikelist.org
>> http://www.bikelist.org/mailman/listinfo/classicrendezv ous
>
>_______________________________________________
>Classicrendezvous mailing list
>Classicrendezvous@bikelist.org
>http://www.bikelist.org/mailman/listinfo/classicrendez vous