Shimano Derailleur question

On Aug 5, 10:31 am, Hell and High Water <[email hidden]>

Quoted message said:

I have seven cogs. Do I have to get a Shimano derailleur that is
specifically for 7?

I see Shimano Sora for 8...

Have Sora shifters, BTW.

-Bob

Hi there.

Nope. 7 and 8 spacings are the same center to center. That is why you
can use 7 of 8 cogs from an 8 speed cassette on a 7 speed body.

Cheers from Peter

On Aug 5, 10:31 am, Hell and High Water <[email hidden]>

Quoted message said:

I have seven cogs. Do I have to get a Shimano derailleur that is
specifically for 7?

I see Shimano Sora for 8...

Have Sora shifters, BTW.

-Bob

Hi there.

7 and 8 speed cassettes have the same center to center distances
between cogs. That is why you can use 7 of the 8 cogs from an 8 speed
cassette on a 7 speed freehub.

Cheers from Peter

Sir Ridesalot said:

7 and 8 spacings are the same center to center.

True for Campy, not true for Shimano. 7 speed spacing for everyone was
5mm. Campy8 was also 5mm but Shimano8 was 4.8mm. Every iteration since
has followed, Campy spacing is 0.2mm wider than Shimano.

For practical purposes, yes, you can use S8 shifters on 7-speed
setups, but they're not spaced the same.

The be-all, end-all article on the subject can be found here:
http://www.ctc.org.uk/DesktopDefault.aspx?TabID=3946

And to answer the OP's question, any Shimano index-compatible
derailleur will work with any shifter/cogset combo, except for 6/7/8-
speed Dura-Ace, with 74xx model numbers.

In article <[email hidden]>,
[email hidden] says...

Quoted message said:

Sir Ridesalot said:

7 and 8 spacings are the same center to center.

True for Campy, not true for Shimano. 7 speed spacing for everyone was
5mm. Campy8 was also 5mm but Shimano8 was 4.8mm. Every iteration since
has followed, Campy spacing is 0.2mm wider than Shimano.

For practical purposes, yes, you can use S8 shifters on 7-speed
setups, but they're not spaced the same.

The be-all, end-all article on the subject can be found here:
http://www.ctc.org.uk/DesktopDefault.aspx?TabID=3946

And to answer the OP's question, any Shimano index-compatible
derailleur will work with any shifter/cogset combo, except for 6/7/8-
speed Dura-Ace, with 74xx model numbers.

I believe my shifters are 3300 series.

My rear derailleur is not even Shimano....

LBS suggested I switch to a Shimano rear to smooth things out. They
ordered one ($30) but if it says 8-speed, I wanted to know if I should
be concerned.

I believe the derailleur they ordered is Shimano Sora, but I'm not clear
on 7 vs. 8.

Thanks!

-Bob

PS: What about the freewheel? I believe my
derailleurs/chain/freewheel are suntour.

On Aug 6, 1:43 pm, Hell and High Water <[email hidden]>

Quoted message said:

In article <[email hidden]>,
[email hidden] says...

Quoted message said:

On Aug 5, 8:07 pm, Sir Ridesalot <[email hidden]> wrote:

Quoted message said:

Quoted message said:

7 and 8 spacings are the same center to center.

Quoted message said:

True for Campy, not true for Shimano. 7 speed spacing for everyone was
5mm. Campy8 was also 5mm but Shimano8 was 4.8mm. Every iteration since
has followed, Campy spacing is 0.2mm wider than Shimano.

Quoted message said:

For practical purposes, yes, you can use S8 shifters on 7-speed
setups, but they're not spaced the same.

Quoted message said:

The be-all, end-all article on the subject can be found here:
http://www.ctc.org.uk/DesktopDefault.aspx?TabID=3946

Quoted message said:

And to answer the OP's question, any Shimano index-compatible
derailleur will work with any shifter/cogset combo, except for 6/7/8-
speed Dura-Ace, with 74xx model numbers.

I believe my shifters are 3300 series.

My rear derailleur is not even Shimano....

LBS suggested I switch to a Shimano rear to smooth things out. They
ordered one ($30) but if it says 8-speed, I wanted to know if I should
be concerned.

I believe the derailleur they ordered is Shimano Sora, but I'm not clear
on 7 vs. 8.

Thanks!

-Bob

PS: What about the freewheel? I believe my
derailleurs/chain/freewheel are suntour.- Hide quoted text -

- Show quoted text -

OK, yeah, Suntour used different spacing from cog-to-cog, not even 5mm
per, so get a new one (and a chain, since they wear together) when you
replace the RD. The Sora should work fine, 6, 7, 8, 9 or 10 speed.

I'd be concerned about your front shifting, too, but if your current
setup shifts OK in the front, leave it alone.