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Raleigh Twenty build - Help needed



 
 
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  #1  
Old November 25th 05, 08:37 PM posted to rec.bicycles.tech
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Default Raleigh Twenty build - Help needed

Greetings,

I am new to the group and am hoping someone can help me.
I am rebuilding an early 70's Raleigh Twenty including front fork,
tire, handlebars and S-A 3-speed hub.

My concern is that the 3 speed hub will not be enough for local terrain
and I would like to update the gearing without big money. i.e. no SRAM
Dual-Drive 3x9

What is the best way to get a rear derailleur gearing onto the SA hub?
The SA uses a 3 spline system, but I doubt I can jam on many extra
sprockets... on extra maybe? Anyone tried this?

Any advice is greatly appreciated...
Mord

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  #2  
Old November 25th 05, 09:45 PM posted to rec.bicycles.tech
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Default Raleigh Twenty build - Help needed

Mordechai wrote:


What is the best way to get a rear derailleur gearing onto the SA hub?
The SA uses a 3 spline system, but I doubt I can jam on many extra
sprockets... on extra maybe? Anyone tried this?

Any advice is greatly appreciated...


I was recently able to find an old "threaded driver" for a
Sturmey-Archer hub. I was in the type of bike shop that has spare
recycled parts from the 1950s.

The driver is the component that holds the rear cogs, and transmits
their torque to the hub's internals. A threaded SA driver has no
splines. Instead it's got the same thread size as a standard freewheel.

My plan is to use this to splice a freewheel onto a 3 speed, but I
haven't taken the time to do it yet. You might try the same tactic.

- Frank Krygowski
  #3  
Old November 27th 05, 02:37 AM posted to rec.bicycles.tech
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Default Raleigh Twenty build - Help needed

On Fri, 25 Nov 2005 21:45:47 GMT, Frank Krygowski
wrote:
Mordechai wrote:

What is the best way to get a rear derailleur gearing onto the SA hub?
The SA uses a 3 spline system, but I doubt I can jam on many extra
sprockets... on extra maybe? Anyone tried this?

Any advice is greatly appreciated...


I was recently able to find an old "threaded driver" for a
Sturmey-Archer hub. I was in the type of bike shop that has spare
recycled parts from the 1950s.

The driver is the component that holds the rear cogs, and transmits
their torque to the hub's internals. A threaded SA driver has no
splines. Instead it's got the same thread size as a standard freewheel.

My plan is to use this to splice a freewheel onto a 3 speed, but I
haven't taken the time to do it yet. You might try the same tactic.


If you're going this route and run into problems, talk to Sheldon. He's
been there and done that. But basically, if you're trying to restore the
bike, don't do this, just refurb the SA and ride it as is. If you're after
a good modern-ish equipped bike, start with something else, or ditch the
SA and put on full derailer gearing. Either the 3x7 or the derailer gear
option will require you to spread the frame, and do a lot of extra work,
to end up with a frankenbike. If you're after a frankenbike because you
enjoy the idea of one, go for it, but it won't look much like an old
Raleigh Roadster.

Jasper
  #4  
Old November 27th 05, 03:10 AM posted to rec.bicycles.tech
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Default Raleigh Twenty build - Help needed

I hunted around for a threaded driver around the LBS and came up empty.
I really want to keep the SA hub so I'll just ride it as is with new
front end. It still may need conversion to 3/32" if the bottom bracket
goes but til then we'll see. Maybe once I've ridden a few hundred I
won't mind the available gearing.

My main reason for rebuilding it is to have an unusual bike that is not
like every other cycle on the road.

BTW it's a Twenty folding bike.
Thanks for the ongoing help,
Mord

  #5  
Old November 27th 05, 08:02 AM posted to rec.bicycles.tech
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Default Raleigh Twenty build - Help needed

Mordechai wrote:

Greetings,

I am new to the group and am hoping someone can help me.
I am rebuilding an early 70's Raleigh Twenty including front fork,
tire, handlebars and S-A 3-speed hub.

My concern is that the 3 speed hub will not be enough for local terrain
and I would like to update the gearing without big money. i.e. no SRAM
Dual-Drive 3x9

What is the best way to get a rear derailleur gearing onto the SA hub?
The SA uses a 3 spline system, but I doubt I can jam on many extra
sprockets... on extra maybe? Anyone tried this?


Raleigh offered optional six and nine speed conversion kits
for that hub. You can remove the HMW-127 spacers on either
side of the sprocket and install two beveled Sturmey
sprockets on the driver facing away from each other ( sizes
over 15 are beveled) to make a six. You'll need a chain a
couple links longer, a shifter and a changer - one which
allows a washer on either side of the rollers to accommodate
your wide chain .

So yes, there's one relatively cheap and simple method. Many
others abound. But did you consider just swapping the cog
size , that is , just a lower geared three speed?

--
Andrew Muzi
www.yellowjersey.org
Open every day since 1 April, 1971
  #6  
Old November 27th 05, 03:59 PM posted to rec.bicycles.tech
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Default Raleigh Twenty build - Help needed

Well, being a Twenty Folder the 20" inch wheel size means that the rear
sprocket is already a 16T. So if I add another I'm only gearing down.

Once I've ridden it some I'll consider replacing the 16T with a 14T
single and forget 3 gears.

Thanks again,
Mord

  #7  
Old November 28th 05, 01:43 AM posted to rec.bicycles.tech
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Default Raleigh Twenty build - Help needed

On Sun, 27 Nov 2005 02:02:11 -0600, A Muzi wrote:

Raleigh offered optional six and nine speed conversion kits
for that hub. You can remove the HMW-127 spacers on either
side of the sprocket and install two beveled Sturmey
sprockets on the driver facing away from each other ( sizes
over 15 are beveled) to make a six. You'll need a chain a
couple links longer, a shifter and a changer - one which
allows a washer on either side of the rollers to accommodate
your wide chain .


What about the 9 speed version, how did that work?

Jasper
  #8  
Old November 28th 05, 02:57 AM posted to rec.bicycles.tech
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Default Raleigh Twenty build - Help needed

On Sun, 27 Nov 2005 02:02:11 -0600, A Muzi wrote:
Raleigh offered optional six and nine speed conversion kits
for that hub. You can remove the HMW-127 spacers on either
side of the sprocket and install two beveled Sturmey
sprockets on the driver facing away from each other ( sizes
over 15 are beveled) to make a six. You'll need a chain a
couple links longer, a shifter and a changer - one which
allows a washer on either side of the rollers to accommodate
your wide chain .


Jasper Janssen wrote:
What about the 9 speed version, how did that work?


Both the six and the nine, made by Cyclo, came as a kit in
an impossibly small box with a few chain links, shifter,
full casing gear cable, chainstay cable stop, Cyclo changer
with pullchain and a proprietary double or triple cog
assembly designed to slip on a splined driver with the
standard circlip. Those cog assemblies had a relatively
thin interface still allowing some chainline adjustment
(spacer-spacer-cog, spacer-cog-spacer, cog-spacer-spacer)

(the kits were cheap -$10 or $12 when a basic rear changer
cost $6)
As Frank noted, a threaded driver is a good start to using a
blocked freewheel. The freewheel body can be brazed or
welded together. Tinkerers have always been drawn to those.
Phil Van Valkenburg's Ultimate Peugeot used a threaded
driver with a 4 speed Regina freewheel on his Sturmey S-5
hub with a triple TA Cyclotouriste triple. . . you get the idea

I'm sure other paths exist. 2 Sturmey cogs back-to-back is
probably the simplest but as always riders have various
criteria and resources so YMMV.
--
Andrew Muzi
www.yellowjersey.org
Open every day since 1 April, 1971
  #9  
Old November 28th 05, 03:23 AM posted to rec.bicycles.tech
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Default Raleigh Twenty build - Help needed


Is it straight-forward then to put a standard freewheel onto the
threaded SA driver, re-dish the wheel and mount it all up? If this is
requires no brazing/welding I'd be more interested in pursuing it.

Seems like this may be the simplest way, even if it takes a while to
find the parts.
Mord

 




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