I have a regular flip flop hub with a single speed and a fixed cog, but if I'm going to coast I have decided I want more gears.

So, has anyone seen, or heard of an internally geared hub where I could mount a fixed cog on the other side?

Alternatively if there is an internally geared up that can lock that might work too. However, I am used to a gear ratio of about 42-14 and wouldn't want something drastically easier or drastically harder.

Anyone know anything?

(this is double posted from single-speed and fixed gear, please don't shoot me)

A company in England makes a cog which bolts to the disc brake mount of a front xtr hub because they feel it makes a better fixed rear hub than what's out there.

Maybe you could try to get one of those and bolt it to a disc-compatible Sturmey Archer. I don't recall the name of the company, sorry. Also, the chainline might be too different between the normal sprocket and the disc mount sprocket.

Sturmey Archer makes a 3 speed hub with a band brake mount on the left side. I'm pretty sure the thread on band brakes use a standard English thread, so you could theoretically thread a track cog on there and use it as a flip flop. Chain line should be within reason.
No way to posistively lock that cog on there though, so I wouldn't be relying on it as a braking device.
https://www.sturmey-archer.com/produc.../id/40/specs/1

All of this is really uneccessary though as Sturmey Archer has now released the 3 speed fixie.
https://www.sturmey-archer.com/products/hubs/cid/3/id/47
It will take a screw on freewheel cog or a Shimano freehub splined cog to make it fixed.

The 6-bolt rotor fixing is by velosolo. They do some good conversion kits that are worth a look.

A few days ago I saw a review of a fixed/freewheel hub that could be switched by rotating a disk, ie no need to remove the hub. Began with A......

Hey, thanks for posting that. That will work beautifully for a mid drive on a project I'm working on.

Not that the bolt on cog isn't a great idea, but I don't think it would work (at least not very well) for what the OP has in mind. Using it on the disk side of a multi-speed hub would require two dramatically different length chains. It is possible to just have two quick links, but this is getting to be an increasingly difficult 'flip'.

Flip flop IGH is complicated by cable routing, when it's in 'fixed mode' your going to have the shifter cables just floating around, not attached to anything.

I guess what the OP wants is a shiftable flip flop hub with 75%, direct drive, 125% and fixed gears. The S3x just came out, can't we be happy with that for now?

Why not just get a 3-speed fixed gear hub?

Man wants to coast some of the time.

It'd be cool to have an FG with a clutch so you could go fixed/free on the fly.

Not a multi gear setup but the New SRAM Torpedo is a Fixed/Freewheel hub which is switched by turning a slotted end shaft in one end of the axle. It takes only a few seconds to switch it between fixed and freewheeling operation. IIRC it comes with spacers for 120mm or 130mm dropouts spacing too.

Almost any IGH with an integral disc brake mount should be capable of having an adapter machined to mount a sprocket but getting the correct chainline for ready flipping of the hub might be difficult.

Thanks everyone. Your insights helped guide my research. Here is my plan, if you could advise me on it's feasibility.

A Shimano Alifine 8 speed hub

Center Lock kit for center lock hub to work with 6 bolt rotor

6 bolt attching cog like this

these sti shifters (these ones are ugly IMO)

As for cable routing, I am willing to re-route the cable when not in use, detaching it from the hub and using these to hold it elsewhere

The difference in chain lines between the two sprockets may be a problem when switching from normal to flipped wheel positions. I am not sure what the normal distance from hub center line to a disc brake is.

The Versa shifter is designed and sized for road drop bars while the Shimano one is sized for MTB bars and would require use of a Hubbub to mount on drop bars.

Assuming the disk brakes are not normally closer to center than the cog would be and the adapter doesn't exceed this would there be a way to push the cog out father?

Spacers perhaps?

Also, how difficult is detaching the shifting cable from an IGH?

Some people think the Nexus/Alfine is hard but not in my experience. downshift to 1, unbolt the wheel, pull the housing out of the cable stop, rotate the hub around and unwrap the cable. when the end barrel rotates a bit it comes out of its hook. I think people forget that you can pull the housing out of the stop first.

Although, if you have full length shift cable housing you might just be able to flip the wheel over and not detach the cable at all, just have it clamped to the downtube so it can run up either left or right chainstays, maybe with a hook/guide on the bottom bracket for tire clearance, nice and tidy