Old 1/8” gear mech
Old 1/8” gear mech
Is there a rear gear mechanism which slides on a bar under the chainstay for a 3 cog 1/8” freewheel? Twin wire.
I guess 1940/50’s.
I guess 1940/50’s.
Re: Old 1/8” gear mech
Doing a Google image search shows lots of possibilities.
https://www.google.com/search?q=1940s+d ... 0&bih=1024
https://www.google.com/search?q=1940s+d ... 0&bih=1024
At the last count:- Peugeot 531 pro, Dawes Discovery Tandem, Dawes Kingpin X3, Raleigh 20 stowaway, 1965 Moulton deluxe, Falcon K2 MTB dropped bar tourer, Rudge Bi frame folder, Longstaff trike conversion on a Giant XTC 840
Re: Old 1/8” gear mech
Don't know about twin wire, but it sounds like an Osgear Super Champion. No jockey wheels etc, something like a movable tuning fork?
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Re: Old 1/8” gear mech
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~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~
~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~
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Re: Old 1/8” gear mech
Your description sounds a bit like a (French) Cyclo derailleur with desmodromic actuation.
Or possibly a very old Simpkex, depends what you mean exactly by ‘bar under chainstay’ And whether you’re talking about the mount or the mechanism.
Or possibly a very old Simpkex, depends what you mean exactly by ‘bar under chainstay’ And whether you’re talking about the mount or the mechanism.
Re: Old 1/8” gear mech
The twin wire moved a vee shaped system which pushed the jockey wheels along a bar, so the jockey wheel moved the chain across the sprockets.
Re: Old 1/8” gear mech
Bit like the French Cyclo, from the pictures, but not. External tension spring
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Re: Old 1/8” gear mech
KM2 wrote:Is there a rear gear mechanism which slides on a bar under the chainstay for a 3 cog 1/8” freewheel? Twin wire.
I guess 1940/50’s.
There is all you might want to know about old derailleurs and their development in this book, which is also available as a pdf.
http://www.cyclepublishing.com/cyclingbooks/dc.html
https://all-med.net/pdf/the-dancing-chain/
It's the same the whole world over
It's the poor what gets the blame
It's the rich what gets the pleasure
Isn't it a blooming shame?
It's the poor what gets the blame
It's the rich what gets the pleasure
Isn't it a blooming shame?
Re: Old 1/8” gear mech
the cyclo 'standard' derailleur (from 1932 onwards) used twin cable actuation
http://www.disraeligears.co.uk/Site/Cyclo_Standard_derailleur.html
cheers
http://www.disraeligears.co.uk/Site/Cyclo_Standard_derailleur.html
cheers
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~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~
~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~
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Re: Old 1/8” gear mech
KM2 wrote:Bit like the French Cyclo, from the pictures, but not. External tension spring
They do have external tension spring, you can see it above the actuation cable, running along under the chain stay and attached to the top of the cage.
Can you describe how then one you’re thinking of is different? Might help us pinpoint for you...
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Re: Old 1/8” gear mech
They do have external tension spring, you can see it above the actuation cable, running along under the chain stay and attached to the top of the cage.
The Cyclo standard, in my old Pitman's Cycling Handbook, looks roughly similar but the Bowden cables both rise vertically up from the mechanism to be clamped to the seatstay. The book (first edition 1950, mine is third, 1960) says it's still in manufacture . Pulling on the cable rotates a pulley that then screws along a fixed shaft taking the rest of the gubbins with it.
Edit. Loads more in the book but apparently only Cyclo standard has twin wire actuation.
Re: Old 1/8” gear mech
cyclo standard (from Birmingham)
cheers
cheers
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~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~
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Re: Old 1/8” gear mech
Trivelox ?
Afraid I don't have the technology to post images.
Afraid I don't have the technology to post images.
Re: Old 1/8” gear mech
the above is a 'bellcank' model, i.e. high normal. There were also 'pullchain' (low normal) models. Perhaps the most (in) famous trivelox gear was the sort that had a fixed position tensioner, and shuffled the sprockets from side to side to change gear. I don't remember seeing a twin-cable version though.
cheers
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~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~
~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~
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Re: Old 1/8” gear mech
Brucey wrote:cyclo standard (from Birmingham)
cheers
Yup, that's the one in my book. In that picture the tension pulley is about 120 degrees round from where it would be in operation.
Seen any more with twin cables?