Shimano 8 cassette

OK, I've read Sheldon's Shimano page and did a search of this newsgroup
and haven't fournd the answer to these questions:

The HG 8 speed cassette has a spacing of 3.0 mm between cogs. I have
an 11t cog that from an HG 8 cassette that yields 3.35 mm. What gives?

The other question is regarding a shimano compatible freehub on a phil
wood hub that had a 8 speed HG cassette that fit fine and replacing it
with an STR 8 speed cassette left a small space requiring a spacer so
the lockring would tighten. IOW, the XT cassette seems almost a ahlf
mm narrower. BTW, I think that 11t cog (from question 1)came from that
original HG cassette. What's going on here?

Please offer some clarity! Thanks.

cliff

On 19 Feb 2005 01:08:49 -0800, "cliff" wrote:

OK, I've read Sheldon's Shimano page and did a search of this newsgroup
and haven't fournd the answer to these questions:

The HG 8 speed cassette has a spacing of 3.0 mm between cogs. I have
an 11t cog that from an HG 8 cassette that yields 3.35 mm. What gives?

It is what it is. If it's 3.35 then that's what it is.

Shimano sometimes made the last position (or two) slightly different
spacing, but I think that was mostly with 7 speeds.

The other question is regarding a shimano compatible freehub on a phil
wood hub that had a 8 speed HG cassette that fit fine and replacing it
with an STR 8 speed cassette left a small space requiring a spacer so
the lockring would tighten. IOW, the XT cassette seems almost a ahlf
m narrower.

Some second position cogs were designed to be assembled together with
a thin 1.2 mm steel spacer. May not be the case with your cassette,
but might be worth ruling out. See
http://www.shimano-europe.com/cyclin..._pdf/R610B.pdf
for an illustrated example.

Also, you can often find exploded views on the Shimano Europe cycling
web site. Just type in the shimano part number for your cassette, e.g.
CS-HG70, in the product search window near the bottom of the page. See
http://www.shimano-europe.com/cycling/

TW, I think that 11t cog (from question 1)came from that
original HG cassette. What's going on here?

Mixed parts? See if every cog carries at least one common letter.
Shimano assigns one or two letters to each "sprocket teeth group", so
a properly matched cluster should have the same letter on every cog.

Please offer some clarity! Thanks.

cliff

Also, and this is a long shot, there was a batch of Shimano XT
cassettes with improper spacing, and the symptom was that the lock
ring never quite tightened. I even saw a one-page bulletin from
Shimano explaining the issue, and that they would replace any faulty
cassette. Maybe you've got one of those?

cliff wrote:

OK, I've read Sheldon's Shimano page and did a search of this newsgroup
and haven't fournd the answer to these questions:

The HG 8 speed cassette has a spacing of 3.0 mm between cogs. I have
an 11t cog that from an HG 8 cassette that yields 3.35 mm. What gives?

Shimano 8-speed cassettes that feature 11 tooth sprockets have this
peculiarity. If you examine the second position sprocket that this 11
fits against, you'll see that there's a recessed area that part of the
11's spacer fits into. The resulting spacing is normal.

This peculiarity only applies to 8-speed cassettes that top out at 11.

The other question is regarding a shimano compatible freehub on a phil
wood hub that had a 8 speed HG cassette that fit fine and replacing it
with an STR 8 speed cassette left a small space requiring a spacer so
the lockring would tighten. IOW, the XT cassette seems almost a ahlf
mm narrower. BTW, I think that 11t cog (from question 1)came from that
original HG cassette. What's going on here?

Are you sure the Phil hub was made to accept an 11 tooth?

See: http://sheldonbrown.com/k7.html#hyperdrivec

If the 8-speed 11 had been used with a second-smallest sprocket that
didn't have the recess spoken of above, this could be equivalent to
adding an extra spacer to the cassette.

Sheldon "It Goes To 11!" Brown
+--------------------------------------------------------------+
| Wherever there is sufficient space for a motor vehicle |
| there must be sufficient space for a bicycle, |
| because the bicycle is smaller. Is that not obviously so? |
| -- John Forester |
+--------------------------------------------------------------+
Harris Cyclery, West Newton, Massachusetts
Phone 617-244-9772 FAX 617-244-1041
http://harriscyclery.com
Hard-to-find parts shipped Worldwide
http://captainbike.com http://sheldonbrown.com

Thank you Dianne and Sheldon. Indeed on the 8 sp cassette from which
the 11 t came is a recessed 12 in the second position. Hence, the cog
doesn't really work with the other 8 sp cassette which was originally
for a 12t small cog. In regards to the 8 speed XTR, I solved the
problem with a 1 mm spacer inboard of the cassette, but will examine
the cassette and the freehub body to try to solve the mystery. Perhaps
I have one of those mis-spaced cassettes, although it seems to shift
OK...

cliff