Ned Mantei, 2017-12-01 14:29+0100:
The problem doesn't seem to be the back of the front fender. Instead,
it's that water is spit forward from the top of the front tire where it
exits the fender, and as this slows I ride into it.

Yes, that would make sense! Thenk you for suggesting that explanation. I
am not sure there is any other solution than wearing a rain pant then…

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Tanguy