Classic & Vintage - 3/32" Sprocket on Sturmey Archer Hub?

Hi everyone, this is my first post on C&V and I'd appreciate any help. I have an old Sturmey Archer 3 speed hub and I'm considering building it up in to a full wheel and putting it on a bike of mine currently equipped with a 3/32" chain. I know technically there are only sprockets available for Sturmey hubs that work with 1/8" chains (from searching on here and Sheldon Brown), but is there a way to bodge it? Thanks for your time.

One approach is to grind down the teeth a bit on the 1/8" cog so it will fit a 3/32" chain.

On one of my Sturmey Archer hubs I was able to use a cog from an 8-speed cassette I broke up...just dremel off some of the splines and it will slip right on. You could do this if you have a circlip and spacers holding the cog on.

If it is the older threaded driver hub, I would imagine a 3/32 track cog would do the trick.

Check Sheldon again. My 3/32" cog came from his shop. Shimano 3 speed cogs also fit SA and are 3/32".

http://inlinethumb58.webshots.com/20985/2739660660068014369S600x600Q85.jpg (http://sports.webshots.com/photo/2739660660068014369dQnybX)
http://inlinethumb19.webshots.com/44050/2376393650068014369S600x600Q85.jpg (http://good-times.webshots.com/photo/2376393650068014369dyKpEe)

I know technically there are only sprockets available for Sturmey hubs that work with 1/8" chains...

Sprockets for garden variety Sturmey 1-3-4-5&7 speed, Shimano 1-3-4-7&8 speed, SRAM/Sachs 2-3-5&7 speed hubs are all interchangeable. The Harris site is clear about this and that they offer 3/32 cogs compatible with Sturmey hubs. There are many other retailers of parts for these hubs as well.

Come up with some odd ball way to bodge it if you want, but no bonus points for accomplishing something the hard way.

As a secondary issue, the Harris site is in error about what the company manufactures. Sturmey in fact does make cogs for both 1/8 and 3/32 chain.

BTW, it might be cheaper to buy a new 1/8 chain than a new 3/32 sprocket.

tcs

Hi everyone, this is my first post on C&V and I'd appreciate any help. I have an old Sturmey Archer 3 speed hub and I'm considering building it up in to a full wheel and putting it on a bike of mine currently equipped with a 3/32" chain. I know technically there are only sprockets available for Sturmey hubs that work with 1/8" chains (from searching on here and Sheldon Brown), but is there a way to bodge it? Thanks for your time.
Not so. Sturmey Archer does make 3/32" cogs. I have a few of them here. If you were on my side of the pond, I could send you one, but I'm sure you should be able to find one locally.

Not so. Sturmey Archer does make 3/32" cogs. I have a few of them here. If you were on my side of the pond, I could send you one, but I'm sure you should be able to find one locally.
Before you do, may sure your crank will also accept 3/32" chain.

Before you do, may sure your crank will also accept 3/32" chain.

:thumb::thumb: You DON'T want to have done all the rest and then find out the chainrings won't work!

Before you do, may sure your crank will also accept 3/32" chain.

The OP did state that the bike currently has 3/32" chain so presumably the chainring takes it.

Hello
Email oldbiketrader@aol.com and will send details for the above.
Regards Derek

There's nothing wrong with getting an 1/8" chain; it will work on a 3/32" chainwheel, if that's what you've got, just fine. Getting a Shimano internal hub sprocket is OK too. I am not sure if the Shimano sprockets are offset the way that many (though not all) of the Sturmey-Archer ones are. Dirtdrop's doesn't appear to be. That offset feature, combined with the location of the two 1/16" thick spacer rings, is useful for getting the chainline aligned with chainwheel.

My cog is offset. I used a track BB, so I have the cog offset toward the inside with the spacer on the outside. My 52 ring clears the chainstay by no more than 2mm.

The invisible wheel shot shows how pretty the new hubs are after the logo is removed. It's clear anodized, so no polishing.

http://inlinethumb55.webshots.com/42550/2748057160068014369S600x600Q85.jpg (http://sports.webshots.com/photo/2748057160068014369DFdAOD)

My cog is offset.

My mistake; sorry. Photo didn't look like it to me.

There's nothing wrong with getting an 1/8" chain; it will work on a 3/32" chainwheel, if that's what you've got, just fine. Getting a Shimano internal hub sprocket is OK too. I am not sure if the Shimano sprockets are offset the way that many (though not all) of the Sturmey-Archer ones are. Dirtdrop's doesn't appear to be. That offset feature, combined with the location of the two 1/16" thick spacer rings, is useful for getting the chainline aligned with chainwheel.


The offset is of no real issue on an SA hub. FWIW if an SA sprocket is smaller than 16t it will be flat anyway. The dished ones have the advantage you can leave the spacers out and run two back to back to get a pseudo 6 speed.

Aaron:)

There's nothing wrong with getting an 1/8" chain; it will work on a 3/32" chainwheel, if that's what you've got, just fine. Getting a Shimano internal hub sprocket is OK too. I am not sure if the Shimano sprockets are offset the way that many (though not all) of the Sturmey-Archer ones are. Dirtdrop's doesn't appear to be. That offset feature, combined with the location of the two 1/16" thick spacer rings, is useful for getting the chainline aligned with chainwheel.

i have a shimano 22T cog (3/32") on an old SA hub, and the offset is about 1mm less than the SA cogs.

SRAM also makes 3/32 sprockets which will fit SA hubs. They are listed as made up to 24 tooth size but they are difficult to find in the USA. I have a NOS 24 tooth that I bought from Sachs prior to the SRAM takeover.

Elite Cycling lists SRAM iM9 sprockets but they will NOT fit other gear hubs.

You can get 25t custom made sprockets from Bike Smith Design (http://bikesmithdesign.com/). Email and ask about them.

Aaron:)

The offset is of no real issue on an SA hub.

It's not an issue if you don't have one with chainline. The advantage of the offset is that by flipping the offset to inside or outside, and configuring the spacers inside, outside or sandwiching the sprocket, you have a greater range of possible chainline.