Ok this is a long-shot: Standard 6 or 7-speed freewheels have something like a hyperglide spline on the body that holds most of the cogs. I'm not sure if it's actually the same as a hyperglide spline. Anyway then the last (usually 11t) cog threads directly onto the freewheel, like a lockring. So it's like a sprocket and lockring in one. Does anyone know what thread is used? Like the diameter and pitch? I want to use the 11t cog by itself as a single-speed cog, but I need to know what thread it is so I can make an adapter.
JackOfDiamonds
Answer to your stated question:
Doing a little googling for "HG lock ring thread pitch" pops up 1.2" x 24 tpi
Crazy bike Jargon:
Freewheel - has the ratcheting mech + the cogs
Freehub - has the ratcheting mech and a hub body that accepts a cassette.
This page spells it out pretty good: Traditional Thread-on Freewheels
If you have a freehub you just need a cog, some spacers and a lock ring and you can set it up single speed.
Here's a kit comes with a lock ring - but no cog: Amazon.com : Q2 Carbon Single Speed Conversion Spacer Kit w/Lockring : Bike Cassettes And Freewheels : Sports & Outdoors
Let us know how it goes
Doing a little googling for "HG lock ring thread pitch" pops up 1.2" x 24 tpi
Crazy bike Jargon:
Freewheel - has the ratcheting mech + the cogs
Freehub - has the ratcheting mech and a hub body that accepts a cassette.
This page spells it out pretty good: Traditional Thread-on Freewheels
If you have a freehub you just need a cog, some spacers and a lock ring and you can set it up single speed.
Here's a kit comes with a lock ring - but no cog: Amazon.com : Q2 Carbon Single Speed Conversion Spacer Kit w/Lockring : Bike Cassettes And Freewheels : Sports & Outdoors
Let us know how it goes
Little more googling and found a page that lists different lockring diameters and pitches:
Sheldon Brown's Bicycle Glossary L
A glossary of bicycle terms with extensive internal cross referencing. This is spread across 30 different files.
www.sheldonbrown.com
I am definitely talking about freewheels, not freehubs. Thank you though.
I also googled and did not find an answer, not even on Sheldon's website. It probably depends on the manufacturer of the freewheel. I will try measuring one with thread guages I guess. Plus, I just found out in this thread that the smallest freewheel size is 14t, when I thought it was 11. They make track cogs that go down to 13t, so I might as well just use track cog threading. Or make something totally custom.
I also googled and did not find an answer, not even on Sheldon's website. It probably depends on the manufacturer of the freewheel. I will try measuring one with thread guages I guess. Plus, I just found out in this thread that the smallest freewheel size is 14t, when I thought it was 11. They make track cogs that go down to 13t, so I might as well just use track cog threading. Or make something totally custom.
Ah, Freewheels are typically 1.37 x 24 tpi. Hence why you can't put an 11 on there. Sheldon has you covered. It's on the first link that I included:
Page down to Freewheel Threading
The standard ISO threading for freewheels is 1.375 x 24 TPI, the same as for standard ISO bottom brackets.
Traditional Thread-on Freewheels
Information on how to rebuild freewheels, which were very common on derailer-equipped bicycles and which offer a great variety of options for sprocket sizes.
www.sheldonbrown.com
Page down to Freewheel Threading
The standard ISO threading for freewheels is 1.375 x 24 TPI, the same as for standard ISO bottom brackets.
| Metric BMX | 1.181" x 25.4 tpi | 30 x 1 mm |
|---|---|---|
| French | 1.366" x 25.4 tpi | 34.7 x 1 mm |
| British | 1.370" x 24 tpi | 34.80 x 1.058 mm |
| ISO | 1.375" x 24 tpi | 34.92 x 1.058 mm |
| Italian | 1.378" x 24 tpi | 35 x 1.058 mm |
| Type | Inch | Metric |
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