[hummie]

im getting a frame made. it's going to be 73mm bottom bracket shell and it was a miscommunication between them and I.

im running it single speed and want to get the chainring as close to the chain stay as possible without hitting. i think i'll have to wait till the frame comes to see what will fit.

i assume isis isnt going anywhere and maybe things are slowed these days but all the sizes will be back in stock. right?

im thinking of brazing a nut on the bottom bracket of the frame that will take this:
Mr Control SSP-11-1 Single Speed Chain Tensioner - The Bikesmiths
instead of running it on the derailleur hanger.
like this:
YESS ERT-B Tensioner Bottom Bracket Mount | Time 2 Shine BMX
if you have any thoughts. using a 50 tooth cog and 17 tooth chainring so...mabye you can guess whats going on here. Cranks - Freewheel ISIS Crank Set - Sick Bike Parts

and this is going to be part of the seat tube

belt down to the double freewheel on the crankset and standard mtb singlespeed rear end (except the tensioner at the front)