On Wed, 15 Apr 2015 07:53:56 -0500, AMuzi wrote:

On 4/15/2015 5:59 AM, John B. Slocomb wrote:
On Tue, 14 Apr 2015 20:16:34 -0700 (PDT), Sir Ridesalot
wrote:

On Tuesday, April 14, 2015 at 11:05:13 PM UTC-4, John B. Slocomb wrote:
A friend has a Dahon folding bike which has a 6 speed rear sprocket
setup. He is wondering what he could do if either the shifter or the
rear sprocket were to wear out as he reckons that the 6 speed setup
might not be readily available.

Would the 6 speed be a free wheel or a cassette?
Can a 6 speed be replaced with a 7 speed, or more, shifter and
cassette/free wheel, without radical modification?

I gather, from looking at adverts and "tests" that the 7 speed Dahon
has a cassette and I believe that the 6 and 7 speed "cog set" are the
same width so is it likely that if he can't replace the 6 speed bits
that a conversion would be relatively easy? New cassette, shifter and
maybe derailer?
--
Cheers,

John B.

If it's a Shimano Uniglide cassette then it's very likely that the last cog is a screw on one unless the hub is one of the transitional ones that would take either a Uniglide or Hyperglide cassette.

Cheers

May Be. I had a look at the Dahon site and they showed a picture of
what they said was a seven speed cassette and it looked just like my 9
and 10 speed cassettes with the separate screw in cap. They make a 8
speed that they say uses a Hyperglide cassette but the 7 and 6 speed
don't seem to include detailed specifications.


Early (1970s through about 1986? 7?) cassette hubs/bodies
were UG format, in which the last sprocket screws on.

Current type is HG using a separate lockring. The seven
bodies are too short for 8/9/10 cassettes. The current
cassette body can run a seven with one spacer behind low
gear and that is a very common setup.

Thanks for that and I'll tell him.
--
Cheers,

John B.