Re: freewheel adapter for square taper spindle
To make it so the front one doesn't spin you would have to separate the rear BB sprockets. How ya going to get just one to freewheel? Now your talking about needing jackshafts etc. If your going to use a 7/8" keyed shaft in the back you can use locktite for bearings to make up the small clearance problem. Please price everything out. I think getting two bottom bracket conversion kits from SBP and using standard sprocketing is going to be cheaper. The front chain spinning friction wouldn't even be noticable. Good Luck
PS simplicity is the key to dependability
Put something FUN between your legs..