Hi, I have a 1997 a4 2.8 quattro and want to bypass my aircon unit I think a bolt has stripped and it is sitting at an angle and wearing the belt, i tried fixing it once but done the same thing,will an of the shelf belt without air con fit if not does anyone know the size of belt I need. Regards bob

Welcome to the Audi Owners Club !

Good to have you onboard.

Hello Bob,

If it were mine, I would be wrapping a length of single core flex around the pulley (and tensioner?) run you want to modify it to, and measure that length. You can then refer to a Gates (or other manufacturer’s ) catalogue for a belt as close to that length and of the number of ribs you have. 
Kind regards, 

Gareth. 

Hi Gareth, i did what you said and measured with a piece of string measured roughly 1780mm under tension with old belt still on so got the right belt for my car without ac which measured 1763mm fitted perfect job done. Thanks Gareth for the advice much appreciated.

Regards bob