Originally Posted by
w1gfh
I had a similar "knack" sound the other day, once every rotation while pedaling. My first thought was a frozen link in the chain, or the chain hitting something. It turned out to be the very edge of the left crank hitting against the very edge of the kickstand. A simple kickstand adjustment cured it.
I've never experienced this condition with any regular AW hub and I can't think of anything in a AW that could cause this. Since the noise is intermittent, only in low gear, shifting is normal and in no particular place in the crank rotation I'm going to guess it has something to do with the drum brake while the clutch spring is fully compressed. Now, I don't know this hub at all, but the coaster brake hubs I've had apart used a worm gear and shuttle to expand the brake pads. Perhaps, the tension from the clutch spring interferes with the braking system somehow and causes the sound. Wild guess