[CR]Re: tapers: to grease or not to grease

(Example: Events:Cirque du Cyclisme:2002)

Date: Sun, 04 Aug 2002 15:58:28 -0700
From: "Greg & Darlene Pitman" <gpit@ix.netcom.com>
To: classicrendezvous@bikelist.org
Subject: [CR]Re: tapers: to grease or not to grease

This is what I would have thought the ultimate answer would be.

I no longer work on bikes. But as a pipefitter, I work on large mechanical equipment. One of the items I deal with is sheaves (pulleys). Big ones. On 2" plus shafts. These are mounted on tapered sleeves with collars on the outside secured by several bolts. The parts come liberally oiled to prevent corrosion. The instructions clearly state that the oil should be completely cleaned before installing in a dry state. As an apprentice, I once disregarded these instructions. I was astounded to see the central spider of a massive steel pulley crack like it was made of rock candy, at less than the specified torque rating. Needless to say, I never made this mistake again.

I know these are not Campagnolo crank arms. But the mechanical concept seems to me to be the same. The lubrication encourages the part to slide too far on to the taper, overstressing it.

I've been reluctant to express my opinion on this subject, for fear of being accused of comparing apples and oranges. So if you think I'm full of crap, be gentle.

Greg Pitman Rancho Cucamonga, CA ( where riding the rollers after work these days means covering the bike to protect it from the steady stream of sweat running off my chin)