Originally Posted by bairdco
you might need to put a "stop" tab on it or something so it doesn't rotate. something as simple as a bolt would work, so it catches under the frame.
on a freewheel there'd be no problems with your design, but a coaster brake could give you problems. a lot of torque is applied to the chain when pedaling and hard braking which could cause it to slip. and if it slipped, you'd not only have a loose chain, but it'd loosen the axle nut as well.
other than that, it's a great idea!
I used to custom hang my derailleurs in my peddling days [to this day] off the axle nut much the same way on a free wheeling multispeed cassette. At the time mostly because I got better performance from the chain. I was trying to wrap as much chain around the small cogs as possible. Seemed that stock arrangements did not target this as much. It was a trade off for me in that from on the fly shifting and absolute longevity with cassette gears ovaling out.
It never failed me! I peddled for years this way! Still kinda do it to this day. Its a we little trade off for semi sluggish shifting. [I split the difference] I trade more chain grab than ease of the shifter. I never had a prob ever with the axle nut holding this arrangement!.
That is a good point Bairdco with the coaster brake tho. I did not snap about that.