On Sun, 14 Mar 2004 03:37:55 GMT, "G.T." <
[email protected]> may
have said:
>Werehatrack wrote:
>> Perhaps the problem is that there is no two-bolt design
>> that is as robust as one with four. Since three different
>> manufacturers have had the same kind of problem, I'd say
>> that there's enough of a pattern to say it's the design
>> itself, not its execution. One would be a random error;
>> two a concidence. Three is prudently regarded as a
>> pattern until proven otherwise.
>>
>
>So I should throw away my perfectly servicable Raceface two-
>bolt stem and buy a four-bolt?
If you wish to panic, by all means. If you wish to be
rational about it, then take a moment periodically to
lightly stress the bars in a manner that will tend to cause
any incipient faliure to be visible, and see if either bolt
boss is showing signs of pulling away from the main body of
the stem. If they aren't, then I would be of the opinion
that it's perfectly safe to ride on wthout worry.
There probably are some two-bolt clamps which are
sufficiently well designed and made that their half life to
failure exceeds the probable life of the bike...but given
the fact that a pattern may be emerging, it is simply
prudent to be a bit more cautious until more data becomes
available. It may be that there really is no actual pattern,
or it may be that the entire problem is in the choice of
materials, or possibly the materials and the design both
contribute to the failures. Of course, given the lack of
details in the recall notices, it's quite possible that one
(or more) of the CPSC recalls does not derive from cap loss
at all. One of the stems has a design that looks (to me) tailor-
made for a failure at the point where the stem narrows near
the steerer clamp. Unfortunately, with their usual lack of
precision about the nature of the failure involved, the CPSC
has not provided enough information for a consumer to make
any kind of informed decision about the seriousness of the
alleged defects, or even to draw a real conclusion about the
nature of them.
Still, the potential for the interrelation merits a slightly
greater amount of diligence in occasional inspection of possibly-
similar units since if a failure there *does* occur, the
effects can be fairly nasty. If the cap stays on but loses
tension, it's possible that it will just be inconvenient. If
the failure is particularly ill-timed, of course, it can be
worse than that. Simply knowing that there *may* be a
problem does not reasonably predicate a scorched-earth
approach to addressing it, but it is equally unwise to
summarily dismiss the possibility that the problem may be
more global than has been disclosed to date.
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