I have Sugino 75 cranks, BB and 48t chainring, Surly 15t cog, Izumi chain.

First comment: I have never had a new chain 'wear-elongate' aka stretch so much. I've run out of tensioner adjustment range when I had 1/8" to spare before. Is Izumi chain known to be this bad? I tension it right and 20mi later (with zero axle slipping) its loose again. It has 700mi on it and still loosens after every ride. (to the point I can move chain up and down ~1/4" and there is feelable and visually noticable backlash on crank arms.

More importantly I have noticed a small skip or micro-jump when cranking hard up farily steep hills seated. It occurs when the left crank arm is just starting downstroke. I wonder if crank arms are tightened correctly to BB axle, or if top/botton chain tension difference could cause this. I'll swing by LBS to be sure on crank install.

I had none of these issues with my previous 3/32" drivetrain.

Al