Russell wrote:
there's no seam under the tyre, only the other sides of the spotwelds. Even the worst wheels I've seen the part of the rim hidden by the tyre hasn't been too bad. I think the rot begins in the seams between the joins.
I'm with Russ on this - I've had wheels where the seam has been utterly "blown", hitting on the kingpins, but when you take the tyre off, the inside of the well is still shiny paint.
Think about the construction of the wheel. You've got two parts - the centre, and the rim.
Broadly speaking, it looks a bit like this :-
Code:
|_ _____| Rim
\__/
<---- Face Back ---->
---
/ Centre
/
\
\__/
<---- Face Back ---->
---
/ Centre
/
\
So the welded seam is exposed to the atmosphere in two places - the front face, and the rear. The rear's where it's most visible, especially the "after effects", but the front is probably the bit where it suffers most. Few people bother to keep the inside of the wheels clean, and they're usually well slathered in grease from the kingpins. OTOH, the front is usually washed regularly, and the thin coat of paint which forms the only barrier to moisture getting in is usually cracked at that point, even if it ever properly sealed the joint - the thin black line at the deepest point...
) all wheels are in very good condition.
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