On Tue, 18 May 2004 12:56:57 GMT, John Everett
<
[email protected]> wrote:
>On Mon, 17 May 2004 13:48:09 -0700, "Mike Rocket J. Squirrel Elliott"
><[email protected]> wrote:
>
>>[email protected] wrote:
>>> On Mon, 17 May 2004 12:52:05 -0700, "Mike Rocket J. Squirrel Elliott"
>>> <[email protected]> wrote:
>>>
>>>
>>>>My Ultegra RD's jockey wheels started squealing a couple weeks ago. I
>>>>applied what I had on hand, some Boeshield, which quieted them down. But
>>>>I wonder what is considered an appropriate lube for these ceramic bearings.
>>>
>>>
>>> Dear Mike,
>>>
>>> Assuming an oiled chain, we'd better hope that chain oil is an
>>> acceptable lube for the pulleys that the chain runs over.
>>>
>>> Carl Fogel
>>
>>Good point.
>
>Good point if the chain is actually oiled, but what about all the
>people who use something like White Lightning or some other wax based
>lube. Also, even if the chain is oiled, by what mechanism does the oil
>find its way into the ceramic bushing? There are those little rubber
>seals that are supposed to keep dirt (and other stuff, like oil?) from
>penetrating the bushing.
>
>To get back to the original question, I use motor oil. About every
>other time I clean and rewax a chain I remove the jockey wheels, clean
>them thoroughly, lube the bushings with a drop of Mobil 1, and
>replace. Some of my jockey wheels have lasted tens of thousands of
>miles.
>
>
>jeverett3<AT>earthlink<DOT>net http://home.earthlink.net/~jeverett3
Dear John,
If oil were somehow bad for ceramic bearings, it's unlikely that they
would be used near bicycle chains. I may be mistaken, but I think that
chain wax is used by a small minority of riders compared to oil.
An oil film might reduce the anti-friction qualities of a dry ceramic
bearing, but I suspect that there's no practical difference on
bicycle chain pulleys for two reasons.
First, there's scarcely any pulley drag discernable by a rider, so any
slight increase or reduction is probably on the order of trimming your
moustache to reduce wind drag.
Second, the road doesn't provide lab conditions, so there will be dust
in the bearing. The seals on pulleys are unlikely to be true seals.
That is, I expect that they're just rubber washers that mean well, but
which are not true seals--if you open the bearings after a month of
riding, I expect that they'll be noticeably dirty and oily.
Peter's suggestion to use grease seems quite reasonable. I was
startled by his warning that the rubber seals may cause the pulleys to
unscrew
Since pulley gears on bicycles are free-spinning idlers, their
bearings should last remarkably well. Plastic pulley gears eventually
wear to to wicked points under steel chains covered with road dust.
Out of curiosity, why do you oil your pulley bearings instead of
waxing them like your chain? I'm not arguing wax versus oil, just
wondering if there's something besides habit or convenience involved.
Have you ever tried wax in the pulleys?
Carl Fogel
