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Aug 13, 2019, 10:20 PM
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Question

Definition of 1/2A classification?


I always thought 1/2A was less that .15.... Is that incorrect?
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Aug 14, 2019, 01:01 AM
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surfer_kris's Avatar
Here is how AMA defines it:

Class ŻA .0000—.0504 cubic inch
Class A .0505—.1525 cubic inch
Class B .1526—.3051 cubic inch
Class D Open .3052—.6500 cubic inch

Hence a Cox .049 and a Cox .051 would be raced in two different classes.
Aug 14, 2019, 08:08 AM
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Quote:
Originally Posted by Ultracon
I always thought 1/2A was less that .15.... Is that incorrect?
1/2A is an 049.
Aug 14, 2019, 04:30 PM
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Quote:
Originally Posted by dan berry
1/2A is an 049.
That is correct, but by the AMA old designations, which is where we got the 1/2A designation from in the first place, an ,020 is also 1/2A.
Aug 14, 2019, 04:47 PM
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That is right
Aug 14, 2019, 05:22 PM
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This is all correct. Some British and Australian classes allow up to .09, and many RC clubs allow .06. just for more participation. This forum says up to .15 to cater to little guy fans. The .020 is occasionally called 1/4A and .010 as 1/8A. The AMA would not have a class for that, or the FAI either AFAIK.


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