What Is This?

[Randall]

This is like a freewheel without a sprocket. The inside is threaded so do I need a threaded
sprocket? This is on my rear fat tire mag rim.

Lost

 

[FurryOnTheInside]

You mean the Shimano pattern freehub?

This is much better than a freewheel cluster because the ratchet is separate from the sprockets, so when your sprockets wear out you don't have to replace the ratchet. This means they could make the ratchet much more expensive and higher quality than is practical in a freewheel cluster.

It also means you have bearings nearer the end of the axle which should eliminate the problem of bent axles as long as the bearings are maintained. It's the best thing ever!

You need a Shimano pattern cassette (the most common type of cassette by far), or single speed for cassette hub "single speed converter kit" which is just a couple of spacers and a sprocket.
You also need a cassette lock ring (male thing that screws into those internal threads) but that should be included with your cassette.

Sheldon says (and I had to correct my post with this QUOTE after fact checking my comments on Sheldon's article)
"Also, hubs marked "8-speed", "9-speed" or "10-speed" will work with any number of sprockets up to 10! (Add a 4.5 mm spacer before installing a 7-speed cassette on an 8-, 9-, or 10-speed hub, and the included 1-mm spacer before installing a 10-speed cassettes on an 8- or 9- speed hub.) Any of these cassettes will work with an 11-speed hub with the addition of another 0.85 mm spacer. 1.85 mm spacers are available so a 10-speed cassette will work on an 11-speed hub. Mavic's Shimano-compatible hubs will work with any number of sprockets up to 11, if you use the necessary spacers.

8 or 9 sprockets can be installed on a 7-speed hub, using 9- or 10-speed spacing. It is also possible to transplant an 8- 9- 10-speed cassette body onto most 7-speed Freehubs."
There must be no side to side play after the lock ring is tightened otherwise it will not change gears properly, or at all in the worst case.


As usual Sheldon Brown has written an article explaining the freehub, with more information than I could include in my post, although he often doesn't cover all the newer developments because he died quite some time ago.
https://www.sheldonbrown.com/k7.html

 

[Randall]

You mean the Shimano pattern freehub?

This is much better than a freewheel cluster because the ratchet is separate from the sprockets, so when your sprockets wear out you don't have to replace the ratchet. This means they could make the ratchet much more expensive and higher quality than is practical in a freewheel cluster.

It also means you have bearings nearer the end of the axle which should eliminate the problem of bent axles as long as the bearings are maintained. It's the best thing ever!

You need a Shimano pattern cassette (the most common type of cassette by far), or single speed for cassette hub "single speed converter kit" which is just a couple of spacers and a sprocket.
You also need a cassette lock ring (male thing that screws into those internal threads) but that should be included with your cassette.

Sheldon says (and I had to correct my post with this QUOTE after fact checking my comments on Sheldon's article)
"Also, hubs marked "8-speed", "9-speed" or "10-speed" will work with any number of sprockets up to 10! (Add a 4.5 mm spacer before installing a 7-speed cassette on an 8-, 9-, or 10-speed hub, and the included 1-mm spacer before installing a 10-speed cassettes on an 8- or 9- speed hub.) Any of these cassettes will work with an 11-speed hub with the addition of another 0.85 mm spacer. 1.85 mm spacers are available so a 10-speed cassette will work on an 11-speed hub. Mavic's Shimano-compatible hubs will work with any number of sprockets up to 11, if you use the necessary spacers.

8 or 9 sprockets can be installed on a 7-speed hub, using 9- or 10-speed spacing. It is also possible to transplant an 8- 9- 10-speed cassette body onto most 7-speed Freehubs."
There must be no side to side play after the lock ring is tightened otherwise it will not change gears properly, or at all in the worst case.


As usual Sheldon Brown has written an article explaining the freehub, with more information than I could include in my post, although he often doesn't cover all the newer developments because he died quite some time ago.
https://www.sheldonbrown.com/k7.html

Thanks Furry. So I guess I will have to modify it to accept a motorized bicycle sprocket.

 

[FurryOnTheInside]

Thanks Furry. So I guess I will have to modify it to accept a motorized bicycle sprocket.

I don't know if that is possible or desirable. You are going to jackshaft and keep it freewheeling? I would expect it would be best to modify a (6 or 7 speed?) cassette by attaching a large sprocket onto its left side, somehow(?!), like an extra big first gear sprocket and use a 3/32" or 1/8" BMX race/ trials chain (Onza KMC Kool chain comes in 3/32" and 1/8").
Actually I'd just use the standard 2mm thick steel sprocket from the front of a mountain bike, personally, as that is pretty much what I used on my left hand side fixed sprockets.
I really don't know what your plans are.
I doubt you can weld to the freehub body without distorting it and ruining the ratcheting function.

 

[Randall]

I don't know if that is possible or desirable. You are going to jackshaft and keep it freewheeling? I would expect it would be best to modify a (6 or 7 speed?) cassette by attaching a large sprocket onto its left side, somehow(?!), like an extra big first gear sprocket and use a 3/32" or 1/8" BMX race/ trials chain (Onza KMC Kool chain comes in 3/32" and 1/8").
Actually I'd just use the standard 2mm thick steel sprocket from the front of a mountain bike, personally, as that is pretty much what I used on my left hand side fixed sprockets.
I really don't know what your plans are.
I doubt you can weld to the freehub body without distorting it and ruining the ratcheting function.

I'm not thinking of jack shafting it. I'm kinda leaning more towards what we are doing with the 2 strokes as far as rear sprocket set up. My thinking is fabricating a sprocket adapter like the manic mechanic one. Going to brainstorm this one.

 

[Randall]

I found this not sure if it will work on mine. Will have to take measurements.
https://www.ebay.com/p/Adapter-and-Sprocket-36t-for-Mag-Wheel-motorized-Bicycle/933756447

 

[gary55]

I don't think that will work. The free hub on the left side of the bike is not going to grab. It will just spin freely.

 

[Randall]

I don't think that will work. The free hub on the left side of the bike is not going to grab. It will just spin freely.

No the hub will be on the right.

 

[gary55]

No the hub will be on the right.

Hold on a minute, it's hard to type with my foot in my mouth.

 

[Spare_Parts]

The picture of the free hub is the right side of the bike. The ebay link goes on the left side and bolts to the disc brake flange if your mag has one.