John´s DUOMATIC Bicycle Project

I received pictures about another DUOMATIC bicycle Project.  Quite often it´s necessary to space the internal gear hubs to fit them perfect in the dropout width of  the frame. Here is a picture of John´s solution:


“Attached is a photo of a washer/spacer I made for my duomatic R2110. It is made of soft aluminium so the teeth on the right-side cone of the hub will grip into it. The two milled flat surfaces will fit into the frame dropout, so it does not rotate. With this washer I have been able to space the R2110 hub to 120mm (same as a standard track frame) without any issues of the axle spinning. Note that the photo shows the washer in an unfinished state – I still had to drill out the central hole so it fits over the axle.”

Finally a picture of the actual bicycle status


Thanks John for sharing your NTWD “Non Turing Washer Design” for the DUOMATIC hub.


  1. Mailjonah

    Is that “Non-turning” or “Non-Touring”?!

  2. John I

    Hi Mailjonah,

    It is a “Non-turning” or anti-rotation washer.


    John I

  3. sean

    I am confused about the comments on several articles about the “right side cone teeth”.

    The cones on my duomatic are perfectly flat with no teeth.

    I filed a pair of keyed washers from a sturmey 3 speed (the sturmey axle was slightly smaller than the sachs axle) and those keep the axle from spinning.

    Am I missing something? Why do you need cone teetch when the axle has flats on it?

    Clarification is appreciated 🙂

    • John I

      Hi Sean,

      There are two models of duomatic hub,
      the older R102, which has flats on the axle,
      and the newer R2110 which has a round axle
      (not flats) and teeth on the right-hand cone.

      From your description it sounds like you have
      the older R012 model.

      Hope this helps,

      John I

      • Hi John, very VERY nice bike, I prefer SAME handlebars (see my Alan Titanal at blogspot), it is classic touring czechoslovak handlebars from 1960 to 1980. I still using onespeed Velosteel coasterbrake, but latest weeks I waiting for Sturmey Archer S2C hub… I have idea for small serie (5 – 8 bikes) with S2C and other S-A parts, and your bike look like a prototype of my idea!!!! When I see first time your bike, I saw !YES! But to this days I have not experiences with kick-back shifting… Have you some video about kick-back shifting? How many cogs you have at front and rear? Thank you for your answer, and for your effort and bike photo. Zdenek Formanek Prague CZE

  4. John and Cathy

    Hi Zdenek,

    Thanks for the compliments on the bike, your machines look really nice as well! I have actually changed my handlebars to something that is even closer to what you have.

    I do not have any video about kickback shifting, but I can say that I find it very enjoyable. You have the simplicity of a singlespeed, but you have an extra gear for climbing or headwinds. I use a 36 tooth chainring and a 20 tooth rear sprocket, which gives gear ratios of 49″ and 66″.
    This is quite low, but then I am not a fast rider, and I like to spin. The top gear is good on the flat area where I ride and the bottom gear is good for starting, hills and headwinds.

    I am also looking forward to try the S2C. I sent an email to Sturmey Archer and they said that it should be available in August.

    John I

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