Suntour freewheel question

Quoted post said:

Originally posted by Jim Rogers
Will an 8sp chain (SRAM PC68) work with a Suntour Winner Pro
Ultra-7 freewheel?

Thanks,

Jim

Yes, Suntour Winner Pro Ultra-7 freewheel uses 2.0 mm thick cogs. Clearence is closer than others, but there is adequate space on the rollers and between the side plates.

The only thicker cogs that I am aware of are the 7 speed Shimano IG.

Jim Rogers said:

Will an 8sp chain (SRAM PC68) work with a Suntour Winner
Pro Ultra-7 freewheel?

Yes. There's no such thing as an "8-speed" chain as
distinct from "7-speed" because sprocket to sprocket
spacing is very similar (identical in some cases) for 7-
and 8-speed clusters.

Sheldon "No Problem" Brown +-------------------------------------------------------
---------+
| The thing about the cold is that you can never tell how
| cold | it is from looking out a kitchen window. You have
| to dress | up, get out training and when you come back,
| you then know | how cold it is. -Sean Kelly |
+-----------------------------------------------------------
-----+ Harris Cyclery, West Newton, Massachusetts Phone 617-244-
9772 FAX 617-244-1041 harriscyclery.comharriscyclery.comOpen ↗ Hard-to-find
parts shipped Worldwide captainbike.comcaptainbike.comOpen ↗
sheldonbrown.comsheldonbrown.comOpen ↗

Jim Rogers said:

Will an 8sp chain (SRAM PC68) work with a Suntour Winner
Pro Ultra-7 freewheel?

Yes but older derailleur cages might do with a slight crimp
at the top of the plates with skinnier chain.

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

Quoted message said:

Yes. There's no such thing as an "8-speed" chain as
distinct from "7-speed" because sprocket to sprocket
spacing is very similar (identical in some cases) for 7-
and 8-speed clusters.

I did know that there is no distinct 7 and 8 speed chains,
but I didn't know if the Suntour Ultra-7 was an exception.
It has the tighter spacing so that the freewheel will take
up the same amount of space as a 6 speed cluster. Since, as
you said, 7 and 8 speeds have nearly the same spacing, I
wondered if the Ultra-7 seven might actually be tighter than
an 8 speed, requiring something like a 9 speed chain.

--Jim

Quoted message said:

Yes but older derailleur cages might do with a slight
crimp at the top of the plates with skinnier chain.

I'm sorry, but I did not understand this response. Could you
please expand?

BTW, I learned a lot about Suntour freewheels on your
website.

--Jim

I said:

Quoted message said:

Yes. There's no such thing as an "8-speed" chain as
distinct from "7-speed" because sprocket to sprocket
spacing is very similar (identical in some cases) for 7-
and 8-speed clusters.

Jim Rogers replied:

Quoted message said:

I did know that there is no distinct 7 and 8 speed chains,
but I didn't know if the Suntour Ultra-7 was an exception.
It has the tighter spacing so that the freewheel will take
up the same amount of space as a 6 speed cluster. Since,
as you said, 7 and 8 speeds have nearly the same spacing,
I wondered if the Ultra-7 seven might actually be tighter
than an 8 speed, requiring something like a 9 speed chain.

"Ultra 6"spacing was ultra-narrow compared to the 5-speed
and full-width 6-speed systems that existed when it was
introduced.

Once Ultra 6 was established, and suitable chains became
available, it became easy to add another sprocket and fit it
into the space formerly ued for full-width 6.

The result was what became the standard 7-speed spacing.
It's redundant to speak of "Ultra 7" because _all_ 7-speeds
use "Ultra" spacing. This used to be considered "narrow" but
as the technology has progressed, these days it's wide by
comparison with 9- and 10-speed stuff.

Sun Tour's version of 7-speed predated the wide acceptance
of indexing, so the spacing is slightly different from one
end of the cluster to the other, but not enough to affect
chain selection, just enough to degrade indexing a bit.

This situation is somewhat analogous to to the hopelessly
confused nomenclature for brake reach, with adjectives like
"long reach" "standard reach" "short reach" "normal reach"
all turned into meaningless noise by evolving practice. Only
numbers can clarify the resulting mess.

Sheldon "Numbers Are Better Than Adjectives" Brown +--------------------------------------------
+
| If it can't be expressed in figures, | it is not
| science; it is opinion. | --Robert A. Heinlein |
+--------------------------------------------+ Harris
Cyclery, West Newton, Massachusetts Phone 617-244-9772 FAX
617-244-1041 harriscyclery.comharriscyclery.comOpen ↗ Hard-to-find parts
shipped Worldwide captainbike.comcaptainbike.comOpen ↗
sheldonbrown.comsheldonbrown.comOpen ↗

Quoted message said:

The result was what became the standard 7-speed spacing.
It's redundant to speak of "Ultra 7" because _all_ 7-
speeds use "Ultra" spacing. This used to be considered
"narrow" but as the technology has progressed, these days
it's wide by comparison with 9- and 10-speed stuff.

Oh, I see. What I was going on was this snippet from an old
Bicycling Magazine about the SunTour GPX shifters (which I
own and want to use):

"The Accushift 7 lever features 3 settings: UL, for index
shifting with SunTour's narrow-spaced Ultra-7 freewheel; F,
for friction shifting; and RE (regular), for index shifting
with most standard-spaced 5- or 6-speed freewheels. The RE
setting is useful when switching to another wheel that does
not have an Ultra-7 freewheel. (Use the F setting for 7-
speed freewheels other than SunTour.)"

That last sentence seemed to indicate that there was a
difference between SunTour and other 7 speeds, thus my
question.

Quoted message said:

Sun Tour's version of 7-speed predated the wide acceptance
of indexing, so the spacing is slightly different from one
end of the cluster to the other, but not enough to affect
chain selection, just enough to degrade indexing a bit.

I have a beautiful older bike with 126mm spacing, and I have
a nice 126mm hub. I want to use the GPX shifters in 7 speed
mode. I know that generally you can use 7 speed freewheels
with 126mm spacing, but occasionally the chain might hit the
seat stay in high gear. In order to avoid that possibility,
I was looking at Ultra-7 freewheels; my thinking being that
they would be a bit narrower and certain to work.

Is this mistaken? Is the Ultra-7 the same width as any other
7-speed freewheel? If it is the same width but with degraded
indexing, I think I'll look at something else.

Thanks for the info,

Jim

Quoted post said:

Originally posted by Jim Rogers
I have a beautiful older bike with 126mm spacing, and I have
a nice 126mm hub. I want to use the GPX shifters in 7 speed
mode. I know that generally you can use 7 speed freewheels
with 126mm spacing, but occasionally the chain might hit the
seat stay in high gear. In order to avoid that possibility,
I was looking at Ultra-7 freewheels; my thinking being that
they would be a bit narrower and certain to work.

Is this mistaken? Is the Ultra-7 the same width as any other
7-speed freewheel? If it is the same width but with degraded
indexing, I think I'll look at something else.

Thanks for the info,

Jim

With GPX Accushift indexed levers, a Suntour Ultra-7 freewheel is what you want. I have the same stuff on one of my bikes. You can use other 7-speed freewheels, but as Sheldon said, indexing may be degraded.

Quoted message said:

Quoted message said:

Yes. There's no such thing as an "8-speed" chain as
distinct from "7-speed" because sprocket to sprocket
spacing is very similar (identical in some cases) for 7-
and 8-speed clusters.

Jim Rogers said:

I did know that there is no distinct 7 and 8 speed chains,
but I didn't know if the Suntour Ultra-7 was an exception.
It has the tighter spacing so that the freewheel will take
up the same amount of space as a 6 speed cluster. Since,
as you said, 7 and 8 speeds have nearly the same spacing,
I wondered if the Ultra-7 seven might actually be tighter
than an 8 speed, requiring something like a 9 speed chain.

At one time that was a skinny chain. At 7.3mm it's
comsidered wide today.

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

Quoted message said:

Quoted message said:

Yes but older derailleur cages might do with a slight
crimp at the top of the plates with skinnier chain.

Jim Rogers said:

I'm sorry, but I did not understand this response. Could
you please expand? BTW, I learned a lot about Suntour
freewheels on your website.

Older derailleurs, especially when worn or bent, shift
skinny chain better when you crimp the top edges of the cage
in closer to the top roller. Not rocket science.

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

(Sheldon Brown)>>The result was what became the standard 7-
speed spacing. It's redundant

Quoted message said:

Quoted message said:

to speak of "Ultra 7" because _all_ 7-speeds use "Ultra"
spacing. This used to be considered "narrow" but as the
technology has progressed, these days it's wide by
comparison with 9- and 10-speed stuff.

Jim Rogers said:

Oh, I see. What I was going on was this snippet from an
old Bicycling Magazine about the SunTour GPX shifters
(which I own and want to use):

"The Accushift 7 lever features 3 settings: UL, for index
shifting with SunTour's narrow-spaced Ultra-7 freewheel;
F, for friction shifting; and RE (regular), for index
shifting with most standard-spaced 5- or 6-speed
freewheels. The RE setting is useful when switching to
another wheel that does not have an Ultra-7 freewheel.
(Use the F setting for 7-speed freewheels other than
SunTour.)"

That last sentence seemed to indicate that there was a
difference between SunTour and other 7 speeds, thus my
question.

(SB)>>Sun Tour's version of 7-speed predated the wide
acceptance of indexing,

Quoted message said:

Quoted message said:

so the spacing is slightly different from one end of the
cluster to the other, but not enough to affect chain
selection, just enough to degrade indexing a bit.

Jim Rogers said:

I have a beautiful older bike with 126mm spacing, and I
have a nice 126mm hub. I want to use the GPX shifters in 7
speed mode. I know that generally you can use 7 speed
freewheels with 126mm spacing, but occasionally the chain
might hit the seat stay in high gear. In order to avoid
that possibility, I was looking at Ultra-7 freewheels; my
thinking being that they would be a bit narrower and
certain to work.

Is this mistaken? Is the Ultra-7 the same width as any
other 7-speed freewheel? If it is the same width but with
degraded indexing, I think I'll look at something else.

Sheldon noted the unique feature of Suntour's Accushift
system which is a veriegated spacing. Sheldon, above:

"the spacing is slightly different from one end of the
cluster to the other"

That's clear, right? Maybe you missed that part. Cogs are
closer together in low gears than in the high end. That's
why you use teh RE setting ( even-spaced clicks) with
"other" uniformly-spaced seven freewheels.

That's also covered here:
yellowjersey.orgaccu.htmlOpen ↗

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

Sheldon Brown said:

The result was what became the standard 7-speed spacing.
It's redundant to speak of "Ultra 7" because _all_ 7-speeds
use "Ultra" spacing. This used to be considered "narrow"
but as the technology has progressed, these days it's wide
by comparison with 9- and 10-speed stuff.

This is an interesting question. Can I take a 5-speed
freewheel, like a regina, where the 6th cog threads onto
the 5th cog, and by choosing the right gears, thread a
SECOND 6th cog, to get a "un-ultra" 7-speed? This "un-
ultra" 7 speed would probably require 130 mm spacing, and
might be something fun to run on a modern bicycle with a
vintage hubset.

- Don Gillies San Diego, CA

Quoted message said:

Sheldon noted the unique feature of Suntour's Accushift
system which is a veriegated spacing. Sheldon, above:

"the spacing is slightly different from one end of the
cluster to the other"

That's clear, right? Maybe you missed that part. Cogs are
closer together in low gears than in the high end. That's
why you use teh RE setting ( even-spaced clicks) with
"other" uniformly-spaced seven freewheels.

Sorry, I'm not usually this dense.

To what does the term "Ultra" refer? Sheldon said "_all_
7-speeds use 'Ultra' spacing." He also said (as you
noted), that there is (unique to SunTour) variable spacing
at each end.

I took these two statements to mean that the Ultra
designation did not refer to the variable spacing, but,
rather, tighter spacing in general. When he said there was
degradation of indexing, I thought he meant with SunTour
shifters (even in the Ultra setting) since I have read many
times that early SunTour index systems were not great.

However, your response indicates that Ultra _means_ variable
spacing and that the degradation in indexing comes from
mixing the Ultra shift setting with non-Ultra freewheels.

So, in the end, I'm still not sure I understand all the
differences between an Ultra and regular 7-speed freewheel.
I know the Ultra has variable spacing, but Sheldon says it's
redundant to talk about Ultra-7 spacing since all freewheels
have the same narrow (but even) spacing.

Is an Ultra-7 freewheel any narrower overall than a regular
7-speed freewheel? If not, is it because the low gear cogs
are slightly narrower than an even-spaced and the high gear
cogs are slightly wider spacing than an even-spaced, which
results in a wash in the overall width of the unit?

I was thinking the wider spaced high gear cogs of an Ultra-
7 were the _same_ spacing as an even-spaced freewheel and
the low gear cogs were "super narrow," resulting in less
overall width. Thus my question about the chain-- I didn't
know if an 8 speed chain would work with those "super-
narrow" spaced gears.

--Jim

Quoted message said:

Older derailleurs, especially when worn or bent, shift
skinny chain better when you crimp the top edges of the
cage in closer to the top roller.

OK, got it...

Quoted message said:

Not rocket science.

Not sure if that was a flame about my confusion or simply a
comment that it is not a difficult procedure to do. If it
was the former, I did not understand because there are cage
plates and chain plates and the way you phrased your answer
made me think you were talking about skinny chains with a
crimp in their plates.

Either way, I really appreciate the info on all of my
SunTour questions.

--Jim

Jim Rogers said:

Quoted message said:

Sheldon noted the unique feature of Suntour's Accushift
system which is a veriegated spacing. Sheldon, above:

"the spacing is slightly different from one end of the
cluster to the other"

That's clear, right? Maybe you missed that part. Cogs are
closer together in low gears than in the high end. That's
why you use teh RE setting ( even-spaced clicks) with
"other" uniformly-spaced seven freewheels.

Sorry, I'm not usually this dense.

To what does the term "Ultra" refer? Sheldon said "_all_
7-speeds use 'Ultra' spacing." He also said (as you
noted), that there is (unique to SunTour) variable spacing
at each end.

I took these two statements to mean that the Ultra
designation did not refer to the variable spacing, but,
rather, tighter spacing in general.

Right, specifically to the spacing used on 7-speed and some
8-speed clusters, approximately 5 mm center-to-center.

Quoted message said:

When he said there was degradation of indexing, I thought
he meant with SunTour shifters (even in the Ultra setting)
since I have read many times that early SunTour index
systems were not great.

However, your response indicates that Ultra _means_
variable spacing and that the degradation in indexing
comes from mixing the Ultra shift setting with non-Ultra
freewheels.

So, in the end, I'm still not sure I understand all the
differences between an Ultra and regular 7-speed
freewheel.

There is no difference. All 7-speed freewheels (and
cassettes) are "Ultra" spaced.

Earlier SunTour units had slightly inconsistent spacing
from one end of the freewheel to the other, but the
_average_ spacing across the freewheel is the same as any
other 7-speed.

Quoted message said:

I know the Ultra has variable spacing, but Sheldon says
it's redundant to talk about Ultra-7 spacing since all
freewheels have the same narrow (but even) spacing.

Yep.

Quoted message said:

Is an Ultra-7 freewheel any narrower overall than a
regular 7-speed freewheel?

No, see above. "Ultra" by the way, is a Sun Tour trademark,
not a generic term.

Quoted message said:

If not, is it because the low gear cogs are slightly
narrower than an even-spaced and the high gear cogs are
slightly wider spacing than an even-spaced, which results
in a wash in the overall width of the unit?

Something like that. See the chart in my Bicycle Glossary
for actual numbers: sheldonbrown.comgloss spOpen ↗
ss.html#spacingk7

Quoted message said:

I was thinking the wider spaced high gear cogs of an Ultra-
7 were the _same_ spacing as an even-spaced freewheel and
the low gear cogs were "super narrow," resulting in less
overall width. Thus my question about the chain-- I didn't
know if an 8 speed chain would work with those "super-
narrow" spaced gears.

No, the difference is much more subtle than that, and chain
compatibility is not an issue. Any modern chain works with
any 7-speed cluster.

In practice, here's how it works out:

If you have, say a Shimano 7-speed system and use an old
SunTour 7-speed freewheel, shifting will be poor, partially
because of the slight spacing mismatch, and partially
because the SunTour freewheel's teeth are not so cleverly
shaped as modern Shimano sprocket teeth are.

If you have a SunTour indexing system, and substitute a
Shimano cluster, the improved shifting due to better
sprocket design will usually more than compensate for the
slight spacing mismatch, resulting in improved shifting.

Sheldon "Shimano Freewheels Are Better As Well As
Cheaper" Brown +------------------------------------------------------
---------+
| Anyone who can't use a slide rule is a cultural
| illiterate, | and should not be allowed to vote. --Robert
| A. Heinlein |
+-----------------------------------------------------------
----+ Harris Cyclery, West Newton, Massachusetts Phone 617-244-
9772 FAX 617-244-1041 harriscyclery.comharriscyclery.comOpen ↗ Hard-to-find
parts shipped Worldwide captainbike.comcaptainbike.comOpen ↗
sheldonbrown.comsheldonbrown.comOpen ↗

Quoted message said:

"The Accushift 7 lever features 3 settings: UL, for index
shifting with SunTour's narrow-spaced Ultra-7 freewheel;
F, for friction shifting; and RE (regular), for index
shifting with most standard-spaced 5- or 6-speed
freewheels. The RE setting is useful when switching to
another wheel that does not have an Ultra-7 freewheel.
(Use the F setting for 7-speed freewheels other than
SunTour.)"

I have a beautiful older bike with 126mm spacing, and I
have a nice 126mm hub. I want to use the GPX shifters in 7
speed mode. I know that generally you can use 7 speed
freewheels with 126mm spacing, but occasionally the chain
might hit the seat stay in high gear. In order to avoid
that possibility, I was looking at Ultra-7 freewheels; my
thinking being that they would be a bit narrower and
certain to work.

Small world? I just acquired a beautiful 80's bike with 126
spacing and Suntour Sprint, including the same DT shifters:

cgi.ebay.comeBayISAPI.dllOpen ↗
96

The Suntour 6 sp freewheel was all gummed up (fixed now),
but I had a Shimano 7 sp lying around so I stuck it in and
it works well. It's the 14-28 $20 (HG?) unit that Sheldon
recommends and sells. I moved the shift lever to the
friction setting. I haven't tried riding it in the RE
indexed setting, but I suppose I'll give that a try just for
the heck of it. But I'm happy with the friction mode.

My chain BARELY clears the chainstay when shifted into the
smallest cog, but it DOES clear it. Also the previous
freewheel has a 24 as the largest cog, and the short cage RD
was fine with that, and barely tolerates shifting onto a 28,
but it does it. I was a bit concerned when I had it on the
workstand, but on the road it all works smoothly so far.

Erik Brooks

<SNIP>

Is an Ultra-7 freewheel any narrower overall than a regular
7-speed freewheel? If not, is it because the low gear cogs
are slightly narrower than an even-spaced and the high gear
cogs are slightly wider spacing than an even-spaced, which
results in a wash in the overall width of the unit?

I was thinking the wider spaced high gear cogs of an Ultra-
7 were the _same_ spacing as an even-spaced freewheel and
the low gear cogs were "super narrow," resulting in less
overall width. Thus my question about the chain-- I didn't
know if an 8 speed chain would work with those "super-
narrow" spaced gears.

--Jim [/B][/QUOTE]

Take a look at Yellow Jersey's site at:
http://www.yellowjersey.org/STCASS.JPG
It's a picture and statement about Suntour's 7 speed *Cassette* with the 3 mm and 2.8 mm spacers.
I don't have a Suntour freewheel or cassette to measure, but they should be .6 mm thinner in the total width due to the thinner spacers in the 3 spaces between the largest 4 cogs.
All other 7 speed cassettes and freewheels that I have measured, with the exception of Suntour have a consistant 5.0 mm spacing.

Donald Gillies inquired:

Quoted message said:

... Can I take a 5-speed freewheel, like a regina, where
the 6th cog threads onto the 5th cog, and by choosing the
right gears, thread a SECOND 6th cog, to get a "un-ultra"
7-speed?

Theoretically, yes, but it's not clear to me that the
requisite second position sprocket (same size male and
female thread) ever existed.

Quoted message said:

This "un-ultra" 7 speed would probably require 130 mm
spacing, and might be something fun to run on a modern
bicycle with a vintage hubset.

That wouldn't have any advantage over a conventional 8-speed
freewheel, and would have all of the disadvantages
associated with 8-speed freewheels.

Sheldon "Think Again" Brown +--------------------------------------------------
+
| What's not worth doing is not worth doing well. | --
| Don Hebb |
+--------------------------------------------------+ Harris
Cyclery, West Newton, Massachusetts Phone 617-244-9772 FAX
617-244-1041 harriscyclery.comharriscyclery.comOpen ↗ Hard-to-find parts
shipped Worldwide captainbike.comcaptainbike.comOpen ↗
sheldonbrown.comsheldonbrown.comOpen ↗

(Jim Rogers) wrote in message

Quoted message said:

Quoted message said:

Sheldon noted the unique feature of Suntour's Accushift
system which is a veriegated spacing. Sheldon, above:

"the spacing is slightly different from one end of the
cluster to the other"

That's clear, right? Maybe you missed that part. Cogs
are closer together in low gears than in the high end.
That's why you use teh RE setting ( even-spaced clicks)
with "other" uniformly-spaced seven freewheels.

Sorry, I'm not usually this dense.

To what does the term "Ultra" refer? Sheldon said "_all_
7-speeds use 'Ultra' spacing." He also said (as you
noted), that there is (unique to SunTour) variable spacing
at each end.

Without putting words in Sheldon's mouth, I believe he was
trying to convey that "ultra" refers to putting 7 speeds in
the space designed for 6 speeds, namely between dropouts
that are 126mm apart; as opposed to 5 speed spacing with
dropout spacing of 120mm or 8 speed spacing which is 130 mm.
Ultra has nothing to do with the spacing between individual
cogs on a freewheel rather it has to do with the space
between the dropouts on the bike frame.

Quoted message said:

I took these two statements to mean that the Ultra
designation did not refer to the variable spacing, but,
rather, tighter spacing in general. When he said there
was degradation of indexing, I thought he meant with
SunTour shifters (even in the Ultra setting) since I
have read many times that early SunTour index systems
were not great.

Maybe the early one's weren't but Superbe Pro "Accushift"
was and is da bomb. I've been using Accushift bar ends,
freewheel and Superbe Pro derailleur on one of my bikes
for 20 years.

Quoted message said:

However, your response indicates that Ultra _means_
variable spacing and that the degradation in indexing
comes from mixing the Ultra shift setting with non-Ultra
freewheels.

Yes. Using a Suntour example, the 7 speed "Accushift"
indexing system, shifters and rear derailleur, works best
which mated with an accushift spaced freewheel. In other
words, all 7 speed freewheels are ultra but not all are
accushift.

Quoted message said:

So, in the end, I'm still not sure I understand all the
differences between an Ultra and regular 7-speed
freewheel. I know the Ultra has variable spacing, but
Sheldon says it's redundant to talk about Ultra-7 spacing
since all freewheels have the same narrow (but even)
spacing.

I think you are confusing the spacing between the dropouts
with the spacing between the individual cogs.

Quoted message said:

Is an Ultra-7 freewheel any narrower overall than a
regular 7-speed freewheel?

No.

If not, is it because the low gear cogs are slightly

Quoted message said:

narrower than an even-spaced and the high gear cogs are
slightly wider spacing than an even-spaced, which results
in a wash in the overall width of the unit?

Yes.

Quoted message said:

I was thinking the wider spaced high gear cogs of an Ultra-
7 were the _same_ spacing as an even-spaced freewheel and
the low gear cogs were "super narrow," resulting in less
overall width. Thus my question about the chain-- I didn't
know if an 8 speed chain would work with those "super-
narrow" spaced gears.

Quoted message said:

--Jim

The only option that is currently widely available other
than a nine or ten speed chain is an "8 speed chain" which
could also be called a five speed, six speed or seven speed
chain because it will work on all.