The answer depends entirely on the grip available. Aquaplaning – when standing water lifts your tyres clear of the road surface completely – leaves you with zero grip, making it impossible to lean the bike over without crashing.
Good road tyres on anti-skid surfaces like shell-grip produce considerable grip, allowing for your “nearly knee-down” circumstances. Good observation on surface condition is the key to not being caught out.
Generally the shinier a surface appears, the worse the grip level. Be particularly careful where the surface is shiny in patches due to wear. The Highways Agency’s favourite quick-fix, a dressing of tar and stone chips, is quick to deteriorate in very hot weather. When it does the tar bleeds through to the surface and a shower of rain following the hot spell can produce a lethal surface. New tarmac surfaces also take a few months to bed in and achieve their maximum abrasiveness.
