Joined: Nov 2006
Posts: 19,810
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From: NJ, NYC, LI
Bikes: 1940s Fothergill, 1959 Allegro Special, 1963? Claud Butler Olympic Sprint, Lambert 'Clubman', 1974 Fuji "the Ace", 1976 Holdsworth 650b conversion rando bike, 1983 Trek 720 tourer, 1984 Counterpoint Opus II, 1993 Basso Gap, 2010 Downtube 8h, and...
No, tire pressure wouldn't be an issue unless you inflated the right tire more than the left tire.
I'm with repechage. Either one of the wheels isn't in the dropout right, or something is bent. Try riding in a straight line through a puddle, while holding both hands on the handlebar. Does it make one water trail, or two? If two, then either one of the wheels isn't in the dropout right, or something is bent.