Late 1960s Schwinn Racer Question...

[[email protected]]

Hi,


First off, thanks to everyone who responded to my previous 2 posts on
my Puch Prima. You were all a great help.

Latest question; I bought a Schwinn Racer from a garage sale and the
owner told me it was about 35 years old. It appears to be a 3 speed
with "indexed" shifting, but it's done without derailleurs. Instead,
a cable connects the shift activator directly to the rear wheel to
(presumably) activate an interior mechanism. I have the following
questions:

1) How do I disconnect this from the wheel? I need to replace the
rear tire and I can't because the cable is in the way.

2) How does this shifting mechanism work? It looks really
interesting, especially since all the previous shifters I have seen
were derailleurs.

3) Are there any sites where I can find more information on this bike?


Thanks in advance.

 

[Ted Bennett]

[email protected] wrote:

> Hi,
>
>
> First off, thanks to everyone who responded to my previous 2 posts on
> my Puch Prima. You were all a great help.
>
> Latest question; I bought a Schwinn Racer from a garage sale and the
> owner told me it was about 35 years old. It appears to be a 3 speed
> with "indexed" shifting, but it's done without derailleurs. Instead,
> a cable connects the shift activator directly to the rear wheel to
> (presumably) activate an interior mechanism. I have the following
> questions:
>
> 1) How do I disconnect this from the wheel? I need to replace the
> rear tire and I can't because the cable is in the way.
>
> 2) How does this shifting mechanism work? It looks really
> interesting, especially since all the previous shifters I have seen
> were derailleurs.
>
> 3) Are there any sites where I can find more information on this bike?
>
>
> Thanks in advance.

You are an owner of a 3-speed internally geared hub. It uses a
planetary, or epicyclic, gear system to get the trio of ratios. These
things are very common; many thousands of examples are in daily use
worldwide.

The shifting cable is attached to a small chain which enters the center
of the axle. It can be unscrewed from its attachment inside the hub, or
alternatively there may be a detachable connection between the actuating
chain and the shift cable.

Internally geared hubs have some advantages over derailer gears. You
can shift at a standstill, the works are protected from the weather, and
a chainguard can be fitted, which will dramatically increase chain life.
However in any gear except direct drive, there are mechanical losses
which are somewhat greater than a clean and lubricated derailler system.
Geared hubs are currently available in 2, 3, 5, 7, 8, and 14 speeds.

To learn more, visit http://www.rohloffusa.com/frame.htm
or http://www.sheldonbrown.com/sturmey-archer.html

Sheldon's pages have a tremendous amount of info, and will help you
identify your hub and service it.

--
Ted Bennett
Portland OR

 

[Werehatrack]

On 15 Jun 2004 20:31:56 -0700, [email protected] may have said:

>Latest question; I bought a Schwinn Racer from a garage sale and the
>owner told me it was about 35 years old. It appears to be a 3 speed
>with "indexed" shifting, but it's done without derailleurs.

Yup. Almost certainly a Sturmey-Archer internally geared hub. It
probably has a little flip-top oil port on it, between the rows of
ports. Give it a small squirt of motor oil in there once in a while.

> Instead,
>a cable connects the shift activator directly to the rear wheel to
>(presumably) activate an interior mechanism. I have the following
>questions:
>
>1) How do I disconnect this from the wheel? I need to replace the
>rear tire and I can't because the cable is in the way.

Where the cable connects to the short piece of chain coming out of the
hub end, there's a knurled jamring and a knurled cable end; the cable
unscrews from the chain there. Loosen the jamring by backing it off a
half turn or so, and you can unscrew the cable end off of the chain
assembly. The jamring keeps the adjustment from getting out of whack;
when reassembling, adjust for proper shifting as detailed in the
instructions on Sheldon Brown's website, and make sure that the
jamring is tightened back up against the cable end to lock it in
place.

>2) How does this shifting mechanism work? It looks really
>interesting, especially since all the previous shifters I have seen
>were derailleurs.

It uses a planetary gear system inside the hub; the cable's motion
shifts bits inside to determine which part of the assembly is engaged
with what. Automotive automatic transmissions use the same kind of
gear assemblies.



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