This information is from an e-mail from Peter Carmichael and is the definitive
answer to the question "Which way round do I fit my Avon ACB10s ?"

Chapter and verse have been done to death before on this list. 

In short the Avon Racing authorised version states:

> * Disregard the direction arrows
> * On the front, the four/five digit product number should face outwards on
> the left hand tyre and inwards on the right.
> * At the rear, the four/five digit product number should face inwards on
> the left hand tyre and outwards on the right.

There is no magic extra grip to be had. It is not the sidewall plies. The
construction (handbuilt) bonds the tread onto the carcass with an overlap.
Run the wrong way, the largest encountered forces could unravel the tread
compound.

Generally ACB10's are available in A33 (Hard compound sold by Caterham)
through A30 to A24 compound.

The definitions from Avon are:
A33		Stronger for very hard saloon use
A31		Durable compound mostly used on saloon cars
A30		Generates higher temperature and grip than A31
A24		Used in medium single seater/soft saloon applications

You cannot get ACB10's in A40 as they fail the Load Rating test because the
desintegrate!

Here's a list of compounds and how to identify them on ACB10's. These
figures are current and the Spec is a 4 digit number on the tyre carcass.




  

    
Spec
 
Size
 
    Compound
 
Load Rating
  
  

    
6356 
 
6.0/21.0-13
 
A30
 
76V
  
  
6357 
 
7.0/22.0-13
 
A31
 
85V
    
6363
  
6.0/21.0-13
 
A24
 
76V
    
6364
  
7.0/22.0-13
 
A24
 
85V
    
6509
  
7.0/22.0-15
 
A31
 
78V
    
6510
  
7.0/22.0-15
 
A24
 
78V
    
6587
  
8.0/22.0-15
 
A31
 
80V
    
6894
  
7.0/21.0-13
 
A24
 
78V
    
6895
  
8.0/22.0-13
 
A24
 
89V
    
6898
  
7.0/21.0-13
 
A30
 
78V
    
6899
  
8.0/22.0-13
 
A31
 
89V
    
7319
  
7.0/22.0-13
 
A31
 
    
7404
  
6.0/21.0-13
 
A33
 
76V
    
7501
  
7.0/22.0-13
 
A33
 
85V
    
7713
  
7.0/22.0-15
 
A33
 
78V
    
8813
  
7.0/22.0-15
 
A33
 
78V
    
8843
  
7.0/21.0-13
 
A30
 
 
    
8844
  
8.0/22.0-13
 
A31
 
 
    
9064
  
6.0/21.0-13
 
A33
 
76V
    
9065
  
7.0/21.0-13
 
A33
 
78V
    
10014
 
8.0/22.0-15
 
A24
 
80V
    
10035
 
7.0/21.0-13
 
A33
 
78V
    
10036
 
8.0/22.0-13
 
A33
 
89V
    
10090
 
7.0/22.0-15
 
A33
 
78V
    
11005
 
7.0/22.0-15
 
4S60
 
78V
    
11099
 
6.0/21.0-13
 
A29
 
76V
    
11110
 
6.0/21.0-13
 
A29
 
76V
  



Where there is no load rating, that tyre is not road legal. So you will not
be able to run in the club sprints Class 5. Got that Mr Scrutineer??

For direction of fitment of ACB10s find where the product number is on the
sidewall and make sure it is the same as shown




I (Peter carmichael) always encourage anybody with doubts to contact Avon directly and ask the questions themselves - ask for "Brian Davis in Racing" (there are two Brian Davis's) on 01225 703101.