I suspect Metformin is the problem with both of us. I think that though many Quacks urge diabetics to exercise more, they do not really understand the nature of cycling as an exercise, and thus, the effect that Metformin may have on our riding. I now take 1/2 of the recommended dose, and take it AFTER I ride. The combination of insulin pump, Byetta and other drugs have my A1c at 6.0 now for 6 months, but I'd really like to "lose the burn" going uphills - some is expected , but not what I normally get. It is a b*tch getting old!