Towards the end of a 300 mile ride on Sunday, I began having trouble with the shift return lever not returning to it's 'static/in-between' position. The problem is especially acute when shifting from third or fourth gears (up or down). It definitely shifts into all gears, but I have to manually return it to the 'static/in-between' position.
I took the bike for a ride again tonight to see if the problem still exists (it does...doesn't matter hot or cold), so it's too hot to start throwing my bare are in around the pipes to start checking things.
Other than the obvious - shift return spring (which was replaced last winter while John Ulrich and I shimmed the 4 speed transmission) - what else should I be looking into?