Mon, 15 Mar 1999 04:09:29 +0800
- Message No. 5237
From: Matthias Becker
Subject: Re: rear wheel bearing
Hi Kirk,
Holy Molly, I've heard already that everything is big in Texas, but a
17'wheel would be quite a mouthful for my little Nukebox (just kiddn!).
The real reason for my e-mail is, that I'm getting a little bit the
creeps when I imagine to heat up a wheel (rim,spokes, hub)to about 400F
(i.e.: > 200 C , when I'm right). The heating might release the inner
tensions (Spannungsfreiglühen), trapped in the welded aluminium rims and
in the casted aluminium hub, which might turn them into potential
corkscrew material. Apart from that, the paint on the hub might have a
"bad Hair Day" after the treatment. In an oven both, hub and bearing,
get heated up evenly. Even considered the fact that the expansion factor
(Ausdehnungskoefficient) of aluminium and a carbon steel are
significantly different, I have my doubts about the procedure. The
crystalline structure of an alloy starts to change from temperatures as
low as 70C, I believe that >200C might have an influence on strength of
resistance, durability and on flexibility, with the threat of a sudden
failure (Gewaltbruch nach Materialverhärtung) or a material failure to
build up (Dauerbruch).
As I'm definitely not interested in a "pissing contest", I would
appreciate if s.o. could truly enlighten us about this heating issue.
stay upright
Matthias (@tic #458)
Kirk Wilson wrote:
>
> Almost forgot: When all else fails you can put the wheel (prefer with no
> tire) into your oven. Heat to about 400F. this will expand the alluminum
> hub enought to get the troublesome bearing out.
>
> KW
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