Re: how would the temperature of an aluminum baseball bat affect its performanc

I love baseball too, but cold weather does not love some aluminum or other 
metal bats.  

Most bats do not do well in cold weather for a number of reasons:

1) The plastic parts, if there are any, do not contract as much as the 
metal.  So end caps on the handle or barrel can easily work loose. This is 
also true of extreme heat where the plastic does not expand as much as the 
metal or actually gets soft.  This is why some bat manufacturers suggest 
storing the bat anywhere but the trunk of a car all summer.

2) The thin wall construction, especially when it is multi-layered does 
not bounce back as well and can get dings or pock marks.  This is due in 
part to the ball get harder in the cold weather and in part to the 
mechanics of the bat.  

Something I have noticed from my own experience is that in colder weather 
the ground is harder and tends to be less even.  Around the Cleveland, 
Ohio area, the cold games in spring are on fields that haven't been used 
much in the last several months, so there is all sorts of pebbles, rocks, 
and lumps on the ground.  A bat thrown down without much concern is very 
likely to get nicks and dings.  As the summer progresses the fields tend 
to be cleaner and softer (at least until a drought kicks in).

3) Bats like any metal object suffer from fatigue with use.  This is a 
slow degradation of the material.  This is not necessarily related to 
weather, but the effects can be magnified if the bat is stiffer because of 
the cold weather.  Anyone who has been "stung" by a hit with a cold bat
has been a victim of a stiffer bat.  

There was a recent article in the Wall Street Journal (The week of Mar 11, 
2001, but I not sure which day) about the DeMarini Bat.  A typical 
DeMarini is so good at transfering energy to the ball, that it has been 
banned in most softball leagues.  One model of the DeMarini is composed of 
two thin walls with a layer of grease in between.  The grease helps 
reduces energy loses and enhances the trampoline effect of the two walls.  
The problem with this bat is that in cold weather the grease doesn't flow 
as well and the bat can get dinged up.

Unrelated to weather, but some softballs manufactured now are very high 
compression rated.  In otherwords, not as spongy.  This also can lead 
to "bees in the hands" but more importantly it will eventually reduce the 
spring of the bat surface or create flat spots.

Sincerely,

Tom "Batting Cage" Cull