That's a special vent hole, it fills up with water and drains away all the rust. You get the same at the back but you have to stand your bike, which then pisses orange on your shoes <--- true story, happens every wet day.
@Ced started
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That's a special vent hole, it fills up with water and drains away all the rust. You get the same at the back but you have to stand your bike, which then pisses orange on your shoes <--- true story, happens every wet day.