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Sachs Offset 4-Spline Cogs?

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Sachs Offset 4-Spline Cogs?

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Old 09-29-22 | 02:53 PM
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Sachs Offset 4-Spline Cogs?

I need to get some replacement cogs, and have noticed that the four lowest cogs on the six-speed freewheel are splined in an off-set fashion. Does this design have a name? I am not sure of what criteria to use when I search for them.

Last edited by 1989Pre; 09-29-22 at 04:14 PM.
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Old 09-29-22 | 04:28 PM
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Originally Posted by 1989Pre
I need to get some replacement cogs, and have noticed that the four lowest cogs on the six-speed freewheel are splined in an off-set fashion. Does this design have a name? I am not sure of what criteria to use when I search for them.
I don't know if they have a specific name.

This was Sachs answer to Shimano Hyper Glide and index shifting. The offset fourth spline is used to make certain the sprockets can only be installed in one direction. These sprockets can't be flipped over.

However, prior to the introduction of Sachs Aris models, there was the Sachs Maillard models. These freewheels only had three equally spaced splines. They are compatible on your Sachs. You just need to make certain you install them with the same orientation as the four spline sprockets (make certain the writing on each faces in the same direction).

What size tooth count and what sequence (in the stack order) do you need?
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Old 09-29-22 | 04:36 PM
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That is great info, Bob. Actually, I am only getting slipping on my two highest (13 and 14T), but would like the splined ones, too.
I think they are 16, 18, 24 and 28T. Anything close to that would be fine, though. Do you live in Georgia, now? Paul
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Old 09-29-22 | 07:11 PM
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Pastor Bob has spoken and is, of course, the undisputed dean of all freewheel related minutiae…..Just to add a few things….The various Maillard non- threaded cogs are sometimes referred to as three or four lobed, splined, or notched.If there was an official nomenclature, it has been lost in the sea of time.
As mentioned, the fourth lobe was placed on the cogs to orient them correctly for indexing purposes after that had come into practice. By then, Maillard had been purchased by Sachs and the index-friendly versions went by the series name “ARIS”. So, generally any four lobed Maillard cog would be from the Sachs Aris era.
Over the years, there were several tooth profiles utilized. The indexed cogs with the four lobed had a “Y” shape profile to grab the chain during a shift and the bottom/single part of the y was to face forward. Just prior to that profile, the cogs were three-lobed and the tooth profile was tapered to one side…It was intended that the chamfered side would face the adjacent smaller cog. You could reverse these cogs for some extra life if they were worn, but you cold also expect poorer shifting by doing so. Earlier still, the cogs were three lobed but the profile was a symmetrical chamfer with a slit cut in the center. These cogs could be reversed to double the wear life with impunity.
Now, to some extent, any of these cogs( with the same internal diameter) could be interchanged among the various eras. The older cogs ( three lobes) could be completely interchanged with the newer ones but shifting performance *may* suffer. Additionally, one could take a four-lobed cog and fit it to an older body by filing off the extra lobe as the remaining three were in the proper position for the older systems.
Simple enough, right? Actually, there was a lot of interchangeability/compatibility designed into the Maillard system. It was intended for custom ratios to be easily assembled and for worn parts to be easily replaced.
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Old 09-30-22 | 06:56 AM
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Originally Posted by 1989Pre
That is great info, Bob. Actually, I am only getting slipping on my two highest (13 and 14T), but would like the splined ones, too.
I think they are 16, 18, 24 and 28T. Anything close to that would be fine, though. Do you live in Georgia, now? Paul
I'm in GA full-time--- when I'm there! Mrs. PB keeps me on the road between the 93-year-old MIL's home in Atlanta and our daughter's home in Nashville. Hey, but that's part of retirement and I'm loving it.

I just located from my move my Sachs spares and I'm about to receive an additional source of spares from hazetguy . So my supply is pretty good.

Thanks El Chaba for the additional information. My earlier response was from my phone and I kept it to a minimum explanation. I have used the newer Sachs sprockets on an old Maillard body when I couldn't locate an original.
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Old 09-30-22 | 07:34 AM
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Originally Posted by pastorbobnlnh
I just located from my move my Sachs spares and I'm about to receive an additional source of spares from hazetguy . So my supply is pretty good.
I imagine there are more Bluefish down there than in Ossipee.

If you want to part with any of those sizes I have listed, that would be nice.

Maybe send me an IM when you get a chance.

Paul W.
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Old 09-30-22 | 07:51 AM
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El Chaba. Thank you for that thorough description. I am running friction with a Suntour Cyclone 6000 r.d., so I am not anticipating any efficiency-reduction if I install some of the three-spline cogs (of either era). I thought I got lucky with a N.O.S. Maillard 14T that I had, but the mounting threads, as you can see, are on the outside of the mounting collar, which, of course, differs from the A.R.I.S. high cog.

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