Is there any such thing as a single speed threaded freewheel (not a freehub) that will accept a standard Shimano-type 9-spline cog?

Why do you want to use a 9-speed cog? My thought is that it would be poorly suited for single speed uses with its ramps making for a tendency to derail unless the chain tension was kept quite. (Such a tight chain leads to an early death for the bearings in FWs, hubs and BBs.)

So, is there a reason beyond "I have these cogs on hand" why you want to do this? (I'm not trying to be hostile. I am always open to learning something new.)

Ben

9 splines. Splines have nothing to do with speeds.

Why?! So you can adjust the chainline without respacing and redishing? Or so you can run smaller than 16t cogs without using a BMX flip flop hub? I can't imagine there ever having been enough interest in such an adapter for anyone to make it. Tell us what your goal is so we can offer some other ideas.

https://www.bikeforums.net/bicycle-me...on-adaper.html

Let me get this straight...you want a freewheel having both threads and splines?

Life is crazy.

Why not just use a standard 9-spline freehub and a spacer kit?

Perhaps the OP wants to use a threaded hub and would like to be able to change gearing w/o needing to change the entire freewheel. This is just speculation on my part, since the OP has provided very limited information.

No, this is not possible. The diameter of a shimano splined interface is smaller than the diameter of the threads for a freewheel.

You could probably have one made if you really want it bad. Just need to make a custom freewheel body. It'll be too fat to run the cog very close to the hub flange, but a range of outer positions could be made available.

I'd guess about $300-500 to have it done, though.

You can look for a 29er wheel with a short single speed freehub.