fg/ss same side of the hub?
 

So i was thinking, what if i made a suicide fg, and then put a ss cog on the outside of that, does any of this make sense?
Then you wouldn't have to take the wheel off if you had a flip flop hub, and a chain tensioner or a old 3 speed derailleur could be put on and change between the fixed and free in a jimmy.

I was wondering if that would work

No. First off there are not enough threads to spin a cog and freewheel on the same side. you also cannot have a fixed gear with a tensioner or derailleur the chain will never be tight enough to stay on the cog and chainring.

No.

Sounds like a fun idea. I imagine any resistance to the pedals would extend a derailleur past it's capability and break it, thereby defeating the purpose of riding with a fixed gear in the first place. Also, the distance between the fixed cog and the edge of the freewheel seems like the chain would get dropped inbetween before it shifted successfully. So, yes you could assemble it but it wouldn't be practical or usable.

Have you seen retro-direct drive bikes? I'm sure you would like those.

what about on an old road bike hub? there are alot of threads there, and i have seen a lot of fixed gears with vertical dropouts that have chain tensioners

thank you, i looked at the retro-direct drive bikes, they are very interesting.

Full of win.

They make a dingle cog for a reason.

Not fixed gears, but single speed freewheels. Chain tensioners don't survive on a fixed gear.

Get an sram torpedo if you don't want to flip your wheel around.

As mentioned, forget the chain tensioner.

However, a fixed cog (on the correct chain line) with a freewheel outboard should work. The trick will be to have enough movement in the dropouts to tension the chain properly. However, I suspect the real deal breaker will be the number of threads, you'll need to make sure you have enough threads for the freewheel to be happy.

Obviously, you won't have an adequate locking ring to support skidding, so it's brakes all the way, which is what you need for SS anyway.

Worth looking at. Please report on your experiments and discoveries. There's a reason flip flop hubs have become popular.

+1