Re: [CR]Orientation of Plastic Bottom Bracket Sleeve

(Example: Framebuilders:Richard Moon)

In-Reply-To: <005f01c7f7cc$7fb1b450$7f151cf0$@net>
References: <005f01c7f7cc$7fb1b450$7f151cf0$@net>
Date: Sat, 15 Sep 2007 16:57:40 -0400
To: "Tom Sanders" <tsan7759142@sbcglobal.net>, <classicrendezvous@bikelist.org>
From: "Sheldon Brown" <CaptBike@sheldonbrown.com>
Subject: Re: [CR]Orientation of Plastic Bottom Bracket Sleeve


Tom Sanders wrote:
>Someone (Mark Agree) was wondering about the proper orientation of it during
>installation.
>
>My question would be why install it at all?

The inside of a bicycle frame is a surprisingly dirty place, even if you have a closed-top seatpost. There are random bits of left-over brazing flux, rust flakes, paint chips and filings floating around in there.

A bottom bracket sleeve keeps these things from contaminating the bearings.

No reputable mechanic would assemble a cup/cone bottom bracket without a sleeve of some sort. That would be totally mono-buttocked.

Back in the day, I used to make 'em out of beer can stock...

Sheldon "Keep The Bearings Clean" Brown --
    Harris Cyclery, West Newton, Massachusetts
       Phone 617-244-9772 FAX 617-244-1041
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