8 speed brifter w/ 7 speed freewheel

[DJA]

Can I use an 8-speed compatible brifter set (Sora 8sp STI) with a
7-speed cluster? What would happen with the additional gear selection?

Thanks
--
David
dja--dot--mail--at--comcast--dot--net

 

[Werehatrack]

On Tue, 21 Sep 2004 10:36:40 -0400, DJA <[email protected]> wrote:

>Can I use an 8-speed compatible brifter set (Sora 8sp STI) with a
>7-speed cluster? What would happen with the additional gear selection?

Won't work[1]. The spacing that the shifter will produce in the der
position will not line up with the sprockets across the width of the
cassette. You need to use a cassette with 8-speed *spacing* with an
8-speed shifter. The spacing on the 7-speed is wider. It's 5.0mm
between sprocket centers on the 7-speed, but only 4.8mm on the
8-speed. This means that if the der lines up on the center sprocket,
it will be .6mm out of alignment at the large and small ends. If it
lines up with the sprocket at one end, it will be 1.2mm off at the
other end.


[1] You may run across someone who says "Hey, I did that, and it
mostly worked okay, yeah it shifted a little funny until I got it
dialed in, and the rear der always made some noise and didn't want to
go into some of the gears right away, but it worked great otherwise."
What they're really saying is that they wouldn't know a
properly-functioning rear der setup from an orifice or an excavation.
--
Typoes are a feature, not a bug.
Some gardening required to reply via email.
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[Gonzo Bob]

Can I use an 8-speed compatible brifter set (Sora 8sp STI) with a
7-speed cluster? What would happen with the additional gear selection?

Thanks
--
David
dja--dot--mail--at--comcast--dot--net

Use 8-speed spacers in your 7-speed cassette and it will work great. You might need a 1mm spacer to put behind your cassette if the lockring doesn't hold it all on securely.

 

[Andrew Webster]

DJA <[email protected]> wrote in message news:<[email protected]>...
> Can I use an 8-speed compatible brifter set (Sora 8sp STI) with a
> 7-speed cluster? What would happen with the additional gear selection?
>
> Thanks

Yes. The extra click will do nothing as the der will already be at the stop.

Andrew Webster

 

[John Carrier]

My Campy 8-sp shifters worked fine with a 7-sp freewheel. Campy's spacing
is .1mm greater than Shimano (IIRC) so the 7sp was plenty close enough.
Your experience may differ.

R / John

"Werehatrack" <[email protected]> wrote in message
news:[email protected]...
> On Tue, 21 Sep 2004 10:36:40 -0400, DJA <[email protected]> wrote:
>
>>Can I use an 8-speed compatible brifter set (Sora 8sp STI) with a
>>7-speed cluster? What would happen with the additional gear selection?
>
> Won't work[1]. The spacing that the shifter will produce in the der
> position will not line up with the sprockets across the width of the
> cassette. You need to use a cassette with 8-speed *spacing* with an
> 8-speed shifter. The spacing on the 7-speed is wider. It's 5.0mm
> between sprocket centers on the 7-speed, but only 4.8mm on the
> 8-speed. This means that if the der lines up on the center sprocket,
> it will be .6mm out of alignment at the large and small ends. If it
> lines up with the sprocket at one end, it will be 1.2mm off at the
> other end.
>
>
> [1] You may run across someone who says "Hey, I did that, and it
> mostly worked okay, yeah it shifted a little funny until I got it
> dialed in, and the rear der always made some noise and didn't want to
> go into some of the gears right away, but it worked great otherwise."
> What they're really saying is that they wouldn't know a
> properly-functioning rear der setup from an orifice or an excavation.
> --
> Typoes are a feature, not a bug.
> Some gardening required to reply via email.
> Words processed in a facility that contains nuts.

 

[Werehatrack]

On Tue, 21 Sep 2004 14:34:30 -0500, "John Carrier" <[email protected]>
wrote:

>My Campy 8-sp shifters worked fine with a 7-sp freewheel. Campy's spacing
>is .1mm greater than Shimano (IIRC) so the 7sp was plenty close enough.
>Your experience may differ.

Campy made an 8-speed cassette with 5.0mm spacing. Sachs did likewise
in 1997, but then went to 4.8mm for 98 and later. The indexed
shifters and der to mate with the Campy would not have been STI, but
the OP specified STI shifters. That's probably why yours worked; not
STI system, took advantage of an otherwise accidental spacing match.
--
Typoes are a feature, not a bug.
Some gardening required to reply via email.
Words processed in a facility that contains nuts.

 

[Douglas Landau]

Werehatrack <[email protected]> wrote in message news:<[email protected]>...
> On Tue, 21 Sep 2004 10:36:40 -0400, DJA <[email protected]> wrote:
>
> >Can I use an 8-speed compatible brifter set (Sora 8sp STI) with a
> >7-speed cluster? What would happen with the additional gear selection?
>
> Won't work[1]. The spacing that the shifter will produce in the der
> position will not line up with the sprockets across the width of the
> cassette. You need to use a cassette with 8-speed *spacing* with an
> 8-speed shifter. The spacing on the 7-speed is wider. It's 5.0mm
> between sprocket centers on the 7-speed, but only 4.8mm on the
> 8-speed. This means that if the der lines up on the center sprocket,
> it will be .6mm out of alignment at the large and small ends. If it
> lines up with the sprocket at one end, it will be 1.2mm off at the
> other end.
>
>
> [1] You may run across someone who says "Hey, I did that, and it
> mostly worked okay, yeah it shifted a little funny until I got it
> dialed in, and the rear der always made some noise and didn't want to
> go into some of the gears right away, but it worked great otherwise."
> What they're really saying is that they wouldn't know a
> properly-functioning rear der setup from an orifice or an excavation.

Does that include Sheldon?

Sheldon Brown wrote:
>In most cases an 8-speed shifter will work with a 7-speed system with no
>problem.
>
>If there should be a problem, there are a couple of easy options to fix it:
>
>•If you change the attachment of the cable at the rear derailer, just by
>moving its clamping point a bit farther from the nearest pivot, you will
>reduce the derailer's travel, cancelling out any descrepancy.
>
>•If you're really, really fussy, you could sub out the spacers between the
>sprockets with thinner ones and make the spacing as exact as anyone could
>wish. I've never found it necessary to actually do this.
>
>Sheldon "Wiggle Room" Brown

Have you actually tried it? Google reveals several other reports that it
does infact work.

-dkl

 

[Luke]

In article <[email protected]>, Werehatrack
<[email protected]> wrote:

> On Tue, 21 Sep 2004 10:36:40 -0400, DJA <[email protected]> wrote:
>
> >Can I use an 8-speed compatible brifter set (Sora 8sp STI) with a
> >7-speed cluster? What would happen with the additional gear selection?
>
> Won't work[1]. The spacing that the shifter will produce in the der
> position will not line up with the sprockets across the width of the
> cassette. You need to use a cassette with 8-speed *spacing* with an
> 8-speed shifter. The spacing on the 7-speed is wider. It's 5.0mm
> between sprocket centers on the 7-speed, but only 4.8mm on the
> 8-speed. This means that if the der lines up on the center sprocket,
> it will be .6mm out of alignment at the large and small ends. If it
> lines up with the sprocket at one end, it will be 1.2mm off at the
> other end.
>
>
> [1] You may run across someone who says "Hey, I did that, and it
> mostly worked okay, yeah it shifted a little funny until I got it
> dialed in, and the rear der always made some noise and didn't want to
> go into some of the gears right away, but it worked great otherwise."
> What they're really saying is that they wouldn't know a
> properly-functioning rear der setup from an orifice or an excavation.

Well I'd like to think I recognize the difference, but your point is
well taken. I mated an older 8spd Shimano 600 brifter to a 7 spd
cassette with no problems. In fact whatever difficulties I had
disappeared: When I was using an 8sp cassette, shifting through the
full range of the cassette's eight cogs in both chain rings was well
nigh impossible without resorting to quick adjustments on the rear
der. downtube shift boss cablestop. The reluctance to shift cleanly was
most pronounced in the end cogs ie. Number 1 and number 8.

This circumstance I attribute to the vagaries of old age (the
shifter's, not mine) and wear and tear. The 8 spd 600 now seems to
prefer 7 spd cassettes in it's dotage. And ironically the setup
perversely reaffirms your contention: The shifter will NOT work with
both 7 and 8 spd cassettes equally.

Luke

 

[Robert Masse]

On Tue, 21 Sep 2004 10:36:40 -0400, DJA <[email protected]> wrote:

>Can I use an 8-speed compatible brifter set (Sora 8sp STI) with a
>7-speed cluster? What would happen with the additional gear selection?
>
>Thanks

I have been using 8 speed Ultegra barcon shifters with a 7 speed
cluster for years. Works very well. There is a slight difference in
cog spacing but not enough to mess with the shifting.

 

[Werehatrack]

On Tue, 21 Sep 2004 21:40:40 -0400, Luke <[email protected]> wrote:

>This circumstance I attribute to the vagaries of old age (the
>shifter's, not mine) and wear and tear. The 8 spd 600 now seems to
>prefer 7 spd cassettes in it's dotage. And ironically the setup
>perversely reaffirms your contention: The shifter will NOT work with
>both 7 and 8 spd cassettes equally.

But you lucked out and found a way to make the old bird act like a new
one; nothing to complain about in that area. So there's one less gear
available; at least now you're getting the one you expect.


--
Typoes are a feature, not a bug.
Some gardening required to reply via email.
Words processed in a facility that contains nuts.

 

[Qui si parla Campagnolo]

DJA-<< Can I use an 8-speed compatible brifter set (Sora 8sp STI) with a
7-speed cluster? What would happen with the additional gear selection?
>><BR><BR>

Yes, just adjust the upper(largest) cog limit screw on the rear der so you get
6 clicks(7s) instead of 8.

Peter Chisholm
Vecchio's Bicicletteria
1833 Pearl St.
Boulder, CO, 80302
(303)440-3535
http://www.vecchios.com
"Ruote convenzionali costruite eccezionalmente bene"

 

[Qui si parla Campagnolo]

Rault-<< Won't work[1]. The spacing that the shifter will produce in the der
position will not line up with the sprockets across the width of the
cassette. You need to use a cassette with 8-speed *spacing* with an
8-speed shifter. The spacing on the 7-speed is wider. >><BR><BR>

It's close enough tho. Kinda like 9/10s ERGO and shimano 9/10s. 7s is 5mm, 8s
is 4.8mm. The top pulley will take care of this.

Peter Chisholm
Vecchio's Bicicletteria
1833 Pearl St.
Boulder, CO, 80302
(303)440-3535
http://www.vecchios.com
"Ruote convenzionali costruite eccezionalmente bene"

 

[Werehatrack]

On 22 Sep 2004 13:16:53 GMT, [email protected] (Qui si parla
Campagnolo ) wrote:

>Rault-<< Won't work[1]. The spacing that the shifter will produce in the der
>position will not line up with the sprockets across the width of the
>cassette. You need to use a cassette with 8-speed *spacing* with an
>8-speed shifter. The spacing on the 7-speed is wider. >><BR><BR>
>
>It's close enough tho. Kinda like 9/10s ERGO and shimano 9/10s. 7s is 5mm, 8s
>is 4.8mm. The top pulley will take care of this.

Maybe, if it's sloppy enough, but the three attempts I've seen (one of
my own included) produced a much less than pleasant result. It took
endless trimming to get it to shift up and down reliably across part
of the range, and it never shifted in both directions reliably across
the whole range at all. Of course, this was with Shimano gear; I
don't have any Campy, and I don't know if there's more forgiveness in
the operation of their ders.

OTOH, one of the other posters gave me a harebrained idea which I
acted on last night. I've had a persistent problem with one
particular older non-exotic Shimano der; it would shift the lower 5 of
7 gears perfectly, but was hard to get to upshift into the top (small)
two without trimming it to where it then shifted down through the
other 5 poorly. So last night, I took the cassette off, pulled the
thin spacer out from between the third cog and the main body, put it
*behind* the cassette, scrounged a thinner make-do shim from my old
stash of automotive junk, clipped it to fit the spot where the other
one came out, and put the mess back together. A few minutes spent
adjusting the cable yielded a rear der that *finally* shifted all 7
gears properly.

Useful information isn't always found where you're looking for it.
Sometimes it pops up where you're not expecting it.
--
Typoes are a feature, not a bug.
Some gardening required to reply via email.
Words processed in a facility that contains nuts.

 

[Benjamin Weiner]

Werehatrack <[email protected]> wrote:
> [email protected] (Qui si parla Campagnolo ) wrote:
>
> >>Rault-<< Won't work[1]. The spacing that the shifter will produce in the der
> >>position will not line up with the sprockets across the width of the
> >>cassette. You need to use a cassette with 8-speed *spacing* with an
> >>8-speed shifter. The spacing on the 7-speed is wider. >><BR><BR>
> >
> >It's close enough tho. Kinda like 9/10s ERGO and shimano 9/10s. 7s is 5mm, 8s
> >is 4.8mm. The top pulley will take care of this.
>
> Maybe, if it's sloppy enough, but the three attempts I've seen (one of
> my own included) produced a much less than pleasant result. It took
> endless trimming to get it to shift up and down reliably across part
> of the range, and it never shifted in both directions reliably across
> the whole range at all. Of course, this was with Shimano gear; I
> don't have any Campy, and I don't know if there's more forgiveness in
> the operation of their ders.

No, really, it works. I have a bike with an 8-speed Shimano STI shifter
and it has been shifting 7 speeds just fine for a year and a half. It works
OK with a 7-speed Sachs freewheel (there was one downshift that hesitated
slightly) and perfectly with a Shimano 7-speed HG cassette. The difference
is due to the superior shift ramps on the Shimano cassette.

It also works with 8 speed barcons. This is useful for setting up a bike
w/o the expense of STI or difficulty of finding 7 speed barcons.

Difficulties with this setup might be due to cabling problems or worn
derailleur pivots. I think my barcon equipped bike's shifting went south
after cyclocross races and offroading made the derailleur sloppy.