Duomatic Anti-Rotation Washers

I recently got hold of some new anti-rotation washers for my Fichtel&Sachs Duomatic hub.

The washers do exactly what they say on the tin... they resist the tendency of the rear axle to rotate under the heavy braking torque.

I found these difficult to source, mainly becuase they are rarely listed in English. They are however listed in the SRAM spare parts catalogue (6Mb PDF).

There are two versions. One version features a pair of lugs that sit in the dropout slot to assist in resisting any rotation. The other type is plain, flat without any extension, with a serrated surface to increase the friction between the washer and the rear dropout.

The SRAM spare parts numbers are :

65 0517 110 10 - Retention washer with extension (Fixierscheibe mit Haltenase, if your googling or ebaying)

65 0517 102 000 - Retention washer without extension (Fixierscheibe ohne Haltenase)

Both are listed on several German bike sites, for less than €1, but the postage costs were extortionate, so I found them on eBay (and ordered with the help of Babelfish translation) at a slightly higher price but with a fair charge for postage and packaging.

I should point out that these washers are for the earlier models with the 10.5mm axle, not the later model with the 9.5mm round axle.

3 thoughts on “Duomatic Anti-Rotation Washers”

  1. The Washers are not intended to take the braking torque, they are just to for the counter torque of the hub’s planetary gear when it is in second gear.

    For the braking torque you need the torque lever.

  2. Correct.
    Since on the Duomatic the shifting is done by a particular backpedal action.

    It seems very strange to me that the “Tab” washers are hard to find; the old shop I used to work before (close to Oxford Circus, London) had always good stock.
    Better use the “tab” ones rather than the “plain” ones, as they are someway more resistant, still not durable as the Sturmey ones. They cannot be swapped beteween Sturmey or Sram.
    The only use of the “Plain” washers in for shallow vetical dropouts, where the “tab” would not engage anywhere.

    As far as the brake arm lever, I reccomend all to use bolts and Nylock nuts, as an arm/clip loose may get free, and the result is a whole new internals, or at least a new coaster cam parts, which may be harder to find than a clip or a washer 😉

  3. Thanks for the good info. I found the plain washers were useful as a spacer, as the OLD of the hub was a few mm smaller than even the dropout spacing of the Moulton Mk 3.

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