Skiptooth Cog Interchangeability

[Duchess]

I have a hacked on cog for the Velosteel hub on my Iver Johnson that has 1/8" teeth and I'm looking for a 3/16" to better work with the skiptooth chain (I didn't expect I would ride the bike this much). Does anyone know if the New Departure D are 3/16" wide and are the same type of thread-on as the Velosteel (which uses the standard track cog thread)? There's a bunch on ebay for much cheaper than the other track cogs.

Thanks

 

[hammer mechanic]

I measured the cog on my New Departure skip tooth hub, and it is for a 3/16" width chain. I don't have a track hub to compare to, but the OD on the ND hub threads is 1.364". I couldn't measure the pitch of the threads.

 

[Duchess]

Thanks! I don't have digital calipers, but unless it's only different by a hair (reading just short of 1 3/8"), that looks like the same diameter.

 

[SSG]

I don't know the dimensions off hand but most thread on coaster brake cogs are the wrong size to fit a track hub. There are plenty of old 1" pitch track cogs around, but you'll pay a few dollars more.

 

[Bicycle808]

I don't know the dimensions off hand but most thread on coaster brake cogs are the wrong size to fit a track hub. There are plenty of old 1" pitch track cogs around, but you'll pay a few dollars more.

Yes, while the modern Velosteels are available with english-threaded drivers, most of the old-timey hubs have their own unique thread specs. Many are close enough where they will actually thread on, but at the risk of stripping the threads... I you can get an English-threaded skiptooth cog, you could run that on your Velosteel driver.