Sturmey to Shimano sprocket splines compatibility

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alexnharvey
Posts: 599
Joined: 10 Jan 2014, 8:39am

Sturmey to Shimano sprocket splines compatibility

Postby alexnharvey » 1 Feb 2019, 6:36pm

Hi, does anyone know if the sturmey archer s3x sprockets will fit on a Shimano freehub? They seem like a good source of 1/8 sprockets for single speed if they'll fit.

Brucey
Posts: 33526
Joined: 4 Jan 2012, 6:25pm

Re: Sturmey to Shimano sprocket splines compatibility

Postby Brucey » 1 Feb 2019, 7:59pm

I think they do, but I have not BTDT. Other sprockets that use variants of the shimano spline include

-shimano DX sprockets (UG)
- Brompton BWR sprockets (these are definitely compatible with the shimano spline, I have swapped these about)

It may be that the NuVinci sprocket shares the same fitting too, although again this seems to be a UG spline.

I note that all the Brompton and SX3 sprockets have slavishly copied the HG spline including the extra-wide 'timing spline'; this means that the sprocket can't be reversed unless you grind a bit off the spline. UG sprockets will fit HG freehubs but UG bodies won't accept HG sprockets without similar modification.

cheers
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~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~

alexnharvey
Posts: 599
Joined: 10 Jan 2014, 8:39am

Re: Sturmey to Shimano sprocket splines compatibility

Postby alexnharvey » 2 Feb 2019, 10:11am

Thanks Brucey. Are the Brompton bwr sprockets available in 1/8? I only see them in 3/32. I would definitely like to reverse the s3x sprocket and I'm not averse to a little filing.

Brucey
Posts: 33526
Joined: 4 Jan 2012, 6:25pm

Re: Sturmey to Shimano sprocket splines compatibility

Postby Brucey » 2 Feb 2019, 5:33pm

BWR sprockets are not available in 1/8" AFAICT.

BTW you can (with a little filing/grinding) fit a standard 1/8" SA sprocket to a steel HG freehub body, but there are only three lugs driving, obviously.

cheers
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~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~

alexnharvey
Posts: 599
Joined: 10 Jan 2014, 8:39am

Re: Sturmey to Shimano sprocket splines compatibility

Postby alexnharvey » 6 Feb 2019, 10:37am

I've been thinking about that. I'd assumed that the 3 lugs with their rounded rather than square shape would damage even the steel freehub body over time. Is that correct? Would I be right in thinking I will have two or three working orientations on the freehub even if there is some wear?

The standard sprockets are both cheaper and easier to find whilst the s3x cassette style are double or triple the price. Other cassette 1/8 sprockets from halo and surly and others are more expensive still.

Brucey
Posts: 33526
Joined: 4 Jan 2012, 6:25pm

Re: Sturmey to Shimano sprocket splines compatibility

Postby Brucey » 6 Feb 2019, 11:45am

with a bit of work you can turn the three rounded lugs into squarer ones. Provided the sprocket is a good fit onto a steel freehub body, the lockring is nice and tight, and the chain isn't adjusted too tightly, it ought to work OK. A key thing is that the sprocket isn't a slack fit on the diameter.

cheers
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~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~

alexnharvey
Posts: 599
Joined: 10 Jan 2014, 8:39am

Re: Sturmey to Shimano sprocket splines compatibility

Postby alexnharvey » 12 Feb 2019, 7:02pm

The s3x sprocket fits on the Shimano freehub with a little slop, no worse than the other unbranded sprocket I have to hand. It's a while since I fitted a Shimano cassette so I can't recall what that fit is like.

Brucey
Posts: 33526
Joined: 4 Jan 2012, 6:25pm

Re: Sturmey to Shimano sprocket splines compatibility

Postby Brucey » 13 Feb 2019, 2:03pm

FWIW individual shimano sprockets are normally a fairly rattly fit onto a freehub body too.

cheers
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~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~