Thanks everyone for the advice. First, it goes without saying that you aren't going to get a great chainring shift under a heavy load although current 105 and Ultegra stuff seems to work flawlessly. Secondly, the limit stops were adjusted correctly.

Anyway, I did come up with a solution. First, I checked the front chainline. Shimano wants you to use a 123mm BB with their Altus crankset to give you a 50mm chainline and I suppose that will work perfectly with a Shimano FD. I measured 50mm. My FD is a Sram 7 speed unit and a little online digging suggests that the optimum chainline is 47.5mm. I did the Sheldon Brown calculations for the cassette and found its centreline to be 47.5mm. It would appear that there was a mismatch between what Shimano and Sram wanted for their setups. Go figure.

I scurried down to the LBS and bought a 118mm BB and it would appear that my shift problems are solved. I had to twist the tail end of the FD cage slightly towards the bike to eliminate any chain rub on the cage and the FD is literally bottomed on its low end stops but everything seems to work . I took the Kona for a little spin down the street and I am happy.

Live and learn. Al