Atom 77 freewheels....
02-02-22, 10:31 AM
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Atom 77 freewheels....
Couple questions for the collective C&V mind regarding Atom 77 freewheels....
Are they all 6-speed, or was there also a 7-speed version?
Is the 'compact' 6-speed for 120mm spacing and the regular 6-speed for 126mm?
Are the cogs the same/spacers different between the compact vs regular (ie, are they interchangeable)?
What was the largest cog available for the Atom 77?
How easy is it to swap out cogs...?
Will a 6-7-8 speed chain work on both the regular and compact versions?
Thanks!
Are they all 6-speed, or was there also a 7-speed version?
Is the 'compact' 6-speed for 120mm spacing and the regular 6-speed for 126mm?
Are the cogs the same/spacers different between the compact vs regular (ie, are they interchangeable)?
What was the largest cog available for the Atom 77?
How easy is it to swap out cogs...?
Will a 6-7-8 speed chain work on both the regular and compact versions?
Thanks!
02-02-22, 11:12 AM
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I don't know much about Atom freewheels, but I recall hearing that only Suntour made 6-speed freewheels that can fit on 120mm hubs.
Here's a BF link discussing freewheel spacing and such:
Modern replacement for Ultra 6 freewheel, 120mm spacing?
Here's a BF link discussing freewheel spacing and such:
Modern replacement for Ultra 6 freewheel, 120mm spacing?
02-02-22, 04:55 PM
#3
Death fork? Naaaah!!
Both Atom 77 and Regina (either BX or CX, I think) could be had as compact 6 cog freewheels for 120mm hubs.
One of each on bikes out in the barn.
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One of each on bikes out in the barn.
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02-02-22, 07:25 PM
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The sprockets are easy to remove. However, few replacements are available.
IIRC, the bodies are different between the Compact and regular 6 speed 77s.
No 7-speed version. Eventually Atom/Maillard/Normandy became or was bought by Sachs, which made the 7 speed Aris model.
IIRC, the bodies are different between the Compact and regular 6 speed 77s.
No 7-speed version. Eventually Atom/Maillard/Normandy became or was bought by Sachs, which made the 7 speed Aris model.
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02-12-22, 11:21 AM
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OK, how about this question... Apparently some of the cogs on an Atom 77 compact are threaded on. If the freewheel is 'French threaded', are the threaded cogs also a different threading from the threaded cogs on an English threaded freewheel, or is it just the freewheel-to-hub threading that is different. In other words, would I be able to swap cogs between a french and an english Atom 77 compact?
Thx
Thx
02-12-22, 02:06 PM
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ehcoplex-
I would think the outer cog thread or pitch would be the same on both English and French threaded hub bodies. I suspect that the regular spaced and Compact spaced freewheel would have different spacers. Atom 77s were made in normal 5 speed (14-24T max) and six speed versions (14-30+T) and six speed compact with the same ratios as the normal. The Compact version works on both 120 and 126 mm wide hubs. The outer cogs unscrew from the body and the inners lift off so cogs are easy to change once the outer cogs are spun off. I use my 77s with Sedisport black or silver chains (basically 6/7 speed) and they work really well whether with normal or Compact formats.
I would think the outer cog thread or pitch would be the same on both English and French threaded hub bodies. I suspect that the regular spaced and Compact spaced freewheel would have different spacers. Atom 77s were made in normal 5 speed (14-24T max) and six speed versions (14-30+T) and six speed compact with the same ratios as the normal. The Compact version works on both 120 and 126 mm wide hubs. The outer cogs unscrew from the body and the inners lift off so cogs are easy to change once the outer cogs are spun off. I use my 77s with Sedisport black or silver chains (basically 6/7 speed) and they work really well whether with normal or Compact formats.
02-12-22, 03:48 PM
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OK, how about this question... Apparently some of the cogs on an Atom 77 compact are threaded on. If the freewheel is 'French threaded', are the threaded cogs also a different threading from the threaded cogs on an English threaded freewheel, or is it just the freewheel-to-hub threading that is different. In other words, would I be able to swap cogs between a french and an english Atom 77 compact?
Thx
Thx
Um, actually I have french 5-speed and english 6-speed and the threading for the sprocket that holds the splined bunch on is the same.
Last edited by oneclick; 02-12-22 at 04:01 PM.
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