From: tomk@netcom.com (Thomas H. Kunich)
Subject: Re: Hubs built for straight spokes
Date: Tue, 08 Sep 92 23:20:16 GMT
Organization: Netcom - Online Communication Services (408 241-9760 guest)

In article <9209082207.AA06674@hplomg.hpl.hp.com> BRANDT_JOBST/HP1900_01@HPLOMG.HPL.HP.COM writes:
>
>Hold the ethnic slurs for a moment will you.  Among Japanese spokes
>are some of the world's best as are other steel products like Tange
>and Ishiwata bike tubing.

There appear to be cheaply made and quite brittle spokes being used
in many of the mass produced bikes. I am told that they are manufactured
in Japan. They fail under large riders and it is common for shops to 
suggest replacement with DT's or Wheelsmith's. While I suppose that it
is possible that it is a wheel building problem it seems to be pretty
universal a problem for that.

>I have seen a lot of wheels and many failures but this whole event
>sounds like nothing I have ever seen nor can I visualize it.  First off,
>did you see these spokes break?  Secondly is this figuratively speaking
>or did all (or most) of the spokes break?

Firstly, I gave the facts in the previous message. You are simply asking
me to repeat them. Yes, I saw this happen and yes, all of the drive
side spokes were affected. The narrow part was _not_ outside at all
but inside at the area where the spoke and hub met. These spokes
were all worn down to about the thickness of a pin. On either side
the spokes were of normal diameter. It was obviously wear caused.

The shop owner said he had never seen anything like it before. But
I assumed that it was simply something that didn't happen except under
special conditions and was nothing unusual or I would have saved some
of the spokes.

>What seems even more implausible is that the spokes were worn thin
>from the action of the hub.

I cannot help the fact that it seems far fetched to you. I am only
reporting what I saw.
>
>You're getting on thin ice here Tom, spokes in a wheel are stressed to
>about 1/3 of their rupture stress and are only unloaded from the weight
>of the rider.  They receive at most a 5% increase or decrease in stress
>from braking or pedaling under the most extreme conditions.  Therefore,
>this stress failure cannot occur but only a fatigue failure.  If it were
>caused by too high a peak stress then the spokes should break the first
>time the rider rides over a sharp bump or off a curb.

If you recall, I posted my problems with spoke breakage here
about a year ago and you (with your usual diplomacy) suggested
that I get a "good set of wheels" to replace my DuraAce hubs with
Campagnolo Lambda rims (note: non-anodized) and 15 gauge DT spokes.

I followed the advice in your nook instead of your net persona and
relaced the wheels with double butted spokes and the problem has
completely diappeared and the wheels stay straight.

I will repeat that I broke four spokes on the rear wheel and
three on the front within 6 months of the bike being new. The same
mechanic worked on the wheels with both sets of spokes. after 
changing from 15 gauge to 14-15-14 the problem disappeared.

I will let you make of that whatever you will.
>
>Without further evidence I feel safe in relegating all of it to the myth
>and lore department.  The whole story sounds like what one who is unclear
>on the concepts might imagine happening... but it doesn't happen that way.

And this is the reason that most people have problems with your
conclusions. When someone witnesses something and your usual reaction
is to say it never happened you don't exactly fill the void with
credability.

This is remeniscient of your comments about the lead filled water
bottle. This has been reported in several books and magazines. Your
comments about it not working or breaking the water bottle cage were
quite humorous. Imagine it being necessary for a rider to have scientific
proof before he tried something like that!

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