Indexed shifting: Suntour vs Shimano

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das...@gmail.com

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Apr 11, 2009, 11:08:55 PM4/11/09
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I have a Suntour 7 or 8 speed bar end shifter.

I also have a XT Shimano rear derailleur, and a 7 speed freehub
cassette.

Is the indexed shifting compatible? I've tried it, and it seems to
work.

jobst....@stanfordalumni.org

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Apr 11, 2009, 11:26:18 PM4/11/09
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someone wrote:

> I have a SunTour 7 or 8 speed bar end shifter.

It depends on center-to-center distance of the sprockets and that was
fairly standard until 9 and 10 speed clusters became the new paradigm.
Therefore, they should work. I use a SunTour indexed downtube shifter
with Shimano 7-speed cassette hubs with no problem.

Jobst Brandt

Chalo

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Apr 12, 2009, 5:32:57 PM4/12/09
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Suntour Accushift index shifting was not considered Shimano-compatible
because Suntour's spacing between sprockets varied across the
cluster. If it works, it works-- but the consensus among bike
mechanics at the time was that it didn't work.

Thus spake Andy Muzi at http://www.yellowjersey.org/accu.html :

"Note: Suntour Accushift systems are variegated spacing!
Unlike Campagnolo EXA or Shimano HG systems, Suntour Accushift cog
spacing is wider between the high gears and narrower at the low end.
Other systems are evenly spaced. For that simple reason one normally
cannot mix Suntour and non-Suntour equipment and still attain proper
index shifting."

Chalo

bjwe...@gmail.com

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Apr 12, 2009, 5:55:58 PM4/12/09
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The mechanical advantages of the shifter and
derailleur also have to match to get proper spacing.
You don't say what derailleur you use. The OP
is using a Suntour shifter and Shimano derailleur.
If it works, it works; but it may be a lucky coincidence.

For the OP, if you get a pair of 7sp or 8sp Shimano
barend shifters to go with your Shimano der and
cassette, that's more or less guaranteed to work
(8 sp and 7sp shifters pull almost the same amount
of cable per click).

Ben

Ryan Cousineau

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Apr 12, 2009, 6:20:02 PM4/12/09
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In article
<33f10324-0bfe-4a7f...@e21g2000yqb.googlegroups.com>,
"b...@mambo.ucolick.org" <bjwe...@gmail.com> wrote:

http://www.ctc.org.uk/desktopdefault.aspx?tabid=3946

--
Ryan Cousineau rcou...@gmail.com http://www.wiredcola.com/
"In other newsgroups, they killfile trolls."
"In rec.bicycles.racing, we coach them."

das...@gmail.com

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Apr 12, 2009, 9:20:22 PM4/12/09
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On Apr 11, 10:08 pm, das...@gmail.com wrote:

> Is the indexed shifting compatible?  I've tried it, and it seems to
> work.

Spoke too soon.

Went out on the trail, and it almost works but doesn't quite work
dependably.

D'oh!

Nick L Plate

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Apr 12, 2009, 10:40:56 PM4/12/09
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Adjust spacer widths between sprockets so the cluster is like a
suntour.

AMuzi

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Apr 12, 2009, 10:59:52 PM4/12/09
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>> das...@gmail.com wrote:
>>> Is the indexed shifting compatible? I've tried it, and it seems to
>>> work.

> das...@gmail.com wrote:
>> Spoke too soon.
>> Went out on the trail, and it almost works but doesn't quite work
>> dependably.
>> D'oh!

Nick L Plate wrote:
> Adjust spacer widths between sprockets so the cluster is like a
> suntour.

Here's your recipe:
http://www.yellowjersey.org/stcass.html

bon chance

--
Andrew Muzi
<www.yellowjersey.org/>
Open every day since 1 April, 1971

Dave Mayer

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Apr 13, 2009, 4:24:59 PM4/13/09
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<das...@gmail.com> wrote in message
news:c68d32ca-9c4b-4f6f...@z19g2000vbz.googlegroups.com...

Suntour is indexed shifting compatible. As long as you use Suntour
shifters, Suntour Accushift-generation rear derailleurs, and compatible
spaced cogsets, then it will index great.

Unfortunately your setup will not work well because you are trying to use an
incompatible Shimano rear derailleur with the very nice Suntour shifters.

Listen up: there seems to be a real mental block in this newsgroup regarding
how indexed shifting works. It is NOT JUST THE COG SPACING, but it is also
the design of the rear derailleurs. All derailleurs do not behave exactly
the same way. Why should they? Suntour requires a different amount of
cable pull compared to Shimano to move the same amount of lateral distance
across the cogset. Specifically, Shimano derailleurs require about 10% more
cable travel to achieve the same amount of movement across the cogset than
Accushift. So the mixed marriage of Suntour and Shimano may sort-of work
over 5 cogs or so, but eventually the cumulative error at the ends of the
cogset will cause sloppy shifting.

Same issue in trying to mix and match Campagnolo and SHimano. Or SRAM and
everything else. They are just plain incompatible.

Recommendation: sell the shifters on Ebay. Or buy an old Suntour Accushift
derailleur on Ebay. Or dig through the boneyard of you local bike shop.
Keep in mind that your right shifter will NOT be compatible with any Suntour
derailleur made before about 1986.

Hank Wirtz

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Apr 13, 2009, 5:52:49 PM4/13/09
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On Apr 13, 1:24 pm, "Dave Mayer" <dave4...@hotmail.com> wrote:

> Same issue in trying to mix and match Campagnolo and SHimano.  Or SRAM and
> everything else.  They are just plain incompatible.

Except that in the case of Campy and SRAM and Shimano, they can be and
often are made to work together, whether by manipulating cable pull
ratios (with a ShiftMate pulley or Hubbub routing) or mixing
coincidentally similar ratios (S8/C10, for instance).

Suntour's variegated spacing pretty much nixes getting anything else
to work with it. At least the three companies today all use consistent
spacing across a cluster, to allow ShiftMates to work.

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