Wheel offset question

[Chris Thorp]

On Nov 2, 2006, at 3:25 PM, H wrote:
>
> The clearance between calipers and spokes is not directly related to
> the offset. Offset describes where the tyre is located relative to the
> hub (and caliper). When you check for fit, remember that the caliper
> may move outward when the pads get replaced (I don't know how your
> particular calipers are designed, so this might not be an issue).
>
> You will be looking for clearance between tyre and sheet metal (you
> are moving the tyre outwards). Imagine a tight corner at high speed.
> The outer suspension will be compressed and the wheel angled, so the
> tyre may rub. Not only will the tyre be ruined, but also your paint.
> Maybe that's how the current tyres got the way they are?
I don't mean to seem argumentative, and I find your advice very  
helpful, but I'm a bit confused how clearance isn't directly related  
to offset.  If I put on a (hypothetical) 10mm spacer, which would  
change my positive offset wheel from ET30 to ET20, wouldn't I have  
exactly 10mm more clearance?

As for the old tires, I'm pretty sure that wasn't the case.  It looks  
like the old tires were just run under-inflated.  They have severe  
shoulder wear just outside the "hard" center potion of the tread on  
both sides of the tires and on three of the four tires.

-Chris