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Re: Source for larger SA anti-rotation washers & cogs

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  • k3eax
    Yes Michael there are are two sizes of Sturmey anti-rotation washers; they are nominally 7mm and 9mm. The 7mm size is the the one commonly found on bicycles
    Message 1 of 19 , Jul 3, 2012
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      Yes Michael there are are two sizes of Sturmey anti-rotation washers; they are nominally 7mm and 9mm. The 7mm size is the the one commonly found on bicycles originally SA equipped. The larger size is used when attempting the SA hub to a bike originally equiped with a coaster brake or derailleur.

      The smaller size washers are plentiful and easily obtained. Most often there are steel and will last for ever. The larger size is difficult to find locally and when available are found to be of what I call "pot metal" that easily cracked.

      PJ has provided a source for 9mm washers that seem to be steel. However, I can't be sure without having them in hand. Another suggestion led to a site which pictured washers that looked discouragingly like the pot-metal.

      Your suggestion of filling the gap left when using 7mm washers on a frame that requires 9mm has some diadvantages ---- like the rod will fall when the wheel is removed.

      Methinks that I will go back to the approach of using metal bands discreetly attached to the dropout and secured with J.B. Weld epoxy.

      I would welcome suggestions for other approaches to the problem.


      Al in Philadelphia







      --- In Geared_hub_bikes@yahoogroups.com, "bikealfa" <mtwils@...> wrote:
      >
      > Caveat - I have not bought new SA stuff in years, except the S3X which appeared to have anti-rotation washers that looked just like the 1960s and up sintered ones.
      >
      > The issue is that the tab in the anti rotation washer was a lot smaller than the dropout slot width. So I used welding rod or some other piece of metal to effectively make the tab larger. I would put it across the washer, "above" both tabs. Yes my previous description was faulty. I only did this with the pressed steel washers; I never tried the sintered ones. I did not do anything fancy or precise. I would put the extra spacer below the axle on the bike, so the bike weight would transfer direct to the axle. Similarly any dropout narrowing sheet metal was brazed to the bottom of the dropout.
      >
      > I believe the sintered anti-rotation washers were inferior on bikes with imprecise dropouts. The pressed steel ones would deform, but I thought the sintered ones would just break.
      >
      > The pressed steel anti-rotation washers did not have as big a tab though - neither in depth into the dropout nor length along the dropout.
      >
      > I have not done any of this stuff in 25 years. I made several sets and have not lost any yet. Back then it did not occur to me that washers for wider slot dropouts might exist. And now I do stupid-light bikes with 11 sprocket aluminum cassettes, so I am unlikely to need these again.
      >
      > --- In Geared_hub_bikes@yahoogroups.com, Al <k3eax@> wrote:
      > >
      > > Thanks Michael for taking the time to reply to my questions.
      > >
      > > I'm not quite able to understand your suggestion regarding the use of the welding rod.
      > >
      > > I have used stainless steel bands secured to each side of both dropouts --four bands in all--- to effectively reduce the opening width. While this works, it is not aesthetically pleasing and the steel bands are easily dislodged when removing and reinstalling the wheel.
      > >
      > >    Al in Philadelphia
      > >
      > >
      > > ________________________________
      > > From: bikealfa <mtwils@>
      > > To: Geared_hub_bikes@yahoogroups.com
      > > Sent: Monday, July 2, 2012 12:09 AM
      > > Subject: [Geared_hub_bikes] Re: Source for larger SA anti-rotation washers & cogs
      > >
      > >
      > >
      > >  
      > >
      > > Sachs used to make a 24 t shipped with their 7 speeds. I thought I had seen recently other 3-spline in either 23 or 24; I did not need them so I did not pay attention.
      > >
      > > What I use for SA anti-rotation washers in derailleur frames is old-style pressed sheet metal ones with welding rod welded across the top of the opening. Unless I brazed a strip onto the frame dropout - at least 2 of my bikes have that.
      > >
      > > I would have thought that Al would have had a few of the pressed sheet metal washers hanging around, as well as a torch.
      > >
      > > Michael Wilson
      > >
      > > --- In mailto:Geared_hub_bikes%40yahoogroups.com, "k3eax" <k3eax@> wrote:
      > > >
      > > > I'm looking for the larger of the two washer seizes and believe this to be 9mm. This larger seize is needed when converting a frame originally equiped with a derailleur.
      > > >
      > > > Also, I would like to know of a source for larger than 22-tooth three-lugged cogs suitable for use on a SA hub.
      > > >
      > > > I have used modified Shimano cogs but find them to need an additional and difficult modify SA spacer.
      > > >
      > > > Any other approaches to rising above the 22-tooth barrier would be appreciated.
      > > >
      > > > Al in Philadelphia
      > > >
      > >
      >
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