Want to chage cassette for 8 speed STI Dura Ace hub

Greetings all

After a 10 year break away from cycling, I recently acquired a road bik
fitted with an almost complete set of Dura Ace 7400 (8 speed STI) kit

Since most of the roads around my home are quite hilly, I am considerin
replacing the existing cassette (Dura Ace 11-23) with something in th
range of a 12-30. FYI, the front crankwheel is 51/39

Questions

Will I be able to fit an 8 speed Shimano cassette (made for mountai
bikes) to my rear hub

Will I likely need a new chain

Thanks in advance

Anthon


-

ze-ant- Will I be able to fit an 8 speed Shimano cassette (made for mountain
bikes) to my rear hub?

Will I likely need a new chain? BRBR


yes and yes.

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

ze-ant- Will I be able to fit an 8 speed Shimano cassette (made for mountain
bikes) to my rear hub?

Will I likely need a new chain? BRBR


yes and yes.

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

On Mon, 29 Mar 2004 06:21:23 GMT, ze-ant
wrote:

Greetings all,

After a 10 year break away from cycling, I recently acquired a road bike
fitted with an almost complete set of Dura Ace 7400 (8 speed STI) kit.

Since most of the roads around my home are quite hilly, I am considering
replacing the existing cassette (Dura Ace 11-23) with something in the
range of a 12-30. FYI, the front crankwheel is 51/39.

Questions:

Will I be able to fit an 8 speed Shimano cassette (made for mountain
bikes) to my rear hub?

Will I likely need a new chain?

Peter's "yes and yes" answer is correct as far as it goes, but there's
one potential problem with your proposal. Shimano claims the maximum
cog capacity of the Dura Ace 8-speed rear derailleur (RD-7402) is 26
teeth. I know this is a bit on the conservative side as I've been
running a 28 tooth large cog on my DA 8-speed bike for a year and a
half now; but that might be pushing the limit. Your proposed 12-30 may
be just a bit too large.

Shimano also claims a maximum total capacity (front difference plus
rear difference) is 26 teeth. My 52/39 and 12-28 totals 29 teeth, and
this works just fine. Your 51/39 and 12-30 totals 30 teeth. I'm not
certain what the real limit is, but while in 39/12 (a combination that
shouldn't be used anyway) the rear derailleur swings back so far the
return chain run clears the upper jockey wheel protection tab on the
cage by mere millimeters.

This is on the stand. I'm guessing if I were to actually ride in this
combination the bouncing of the chain might actually bring it in
contact with the cage.


jeverett3ATearthlinkDOTnet http://home.earthlink.net/~jeverett3

On Mon, 29 Mar 2004 06:21:23 GMT, ze-ant
wrote:

Greetings all,

After a 10 year break away from cycling, I recently acquired a road bike
fitted with an almost complete set of Dura Ace 7400 (8 speed STI) kit.

Since most of the roads around my home are quite hilly, I am considering
replacing the existing cassette (Dura Ace 11-23) with something in the
range of a 12-30. FYI, the front crankwheel is 51/39.

Questions:

Will I be able to fit an 8 speed Shimano cassette (made for mountain
bikes) to my rear hub?

Will I likely need a new chain?

Peter's "yes and yes" answer is correct as far as it goes, but there's
one potential problem with your proposal. Shimano claims the maximum
cog capacity of the Dura Ace 8-speed rear derailleur (RD-7402) is 26
teeth. I know this is a bit on the conservative side as I've been
running a 28 tooth large cog on my DA 8-speed bike for a year and a
half now; but that might be pushing the limit. Your proposed 12-30 may
be just a bit too large.

Shimano also claims a maximum total capacity (front difference plus
rear difference) is 26 teeth. My 52/39 and 12-28 totals 29 teeth, and
this works just fine. Your 51/39 and 12-30 totals 30 teeth. I'm not
certain what the real limit is, but while in 39/12 (a combination that
shouldn't be used anyway) the rear derailleur swings back so far the
return chain run clears the upper jockey wheel protection tab on the
cage by mere millimeters.

This is on the stand. I'm guessing if I were to actually ride in this
combination the bouncing of the chain might actually bring it in
contact with the cage.


jeverett3ATearthlinkDOTnet http://home.earthlink.net/~jeverett3

Thomas Reynolds wrote in message


[...]

An alternative is to use a mountain bike rear derailleur but you will
need to use a 9 speed cassette. I am currently using an 11-34 9-sp
cassette with an XT derailleur, adjusting it to shift the larger 8
cogs. It works very well.

Since all Deore components are designed around 9-sp what does "adjusting it
to shift the larger 8 cogs" mean?

--

"I'm proud that I live in a country where witnessing two hours of bloody,
barbarous torture in gloating detail is considered indicia of religious
piety, whereas a mere second gazing upon a woman's breast is cause for
outraged apoplexy."
Betty Bowers, http://www.bettybowers.com/melgibsonpassion.html

Thomas Reynolds wrote in message


[...]

An alternative is to use a mountain bike rear derailleur but you will
need to use a 9 speed cassette. I am currently using an 11-34 9-sp
cassette with an XT derailleur, adjusting it to shift the larger 8
cogs. It works very well.

Since all Deore components are designed around 9-sp what does "adjusting it
to shift the larger 8 cogs" mean?

--

"I'm proud that I live in a country where witnessing two hours of bloody,
barbarous torture in gloating detail is considered indicia of religious
piety, whereas a mere second gazing upon a woman's breast is cause for
outraged apoplexy."
Betty Bowers, http://www.bettybowers.com/melgibsonpassion.html

Someone wrote:

After a 10 year break away from cycling, I recently acquired a road bike
fitted with an almost complete set of Dura Ace 7400 (8 speed STI) kit.

Since most of the roads around my home are quite hilly, I am considering
replacing the existing cassette (Dura Ace 11-23) with something in the
range of a 12-30. FYI, the front crankwheel is 51/39.

Questions:

Will I be able to fit an 8 speed Shimano cassette (made for mountain
bikes) to my rear hub?

Yes. 12-30 is pushing the envelope for your old derailer's capacity,
but will probably work with careful setup.

Will I likely need a new chain?

Yes. You should always replace the chain when installing a new cluster
anyway.

There are a number of interchangeability quirks with older Dura-Ace
stuff, and it would be worth your while to thoroughly study my Web page
on this topic: http://sheldonbrown.com/dura-ace

Sheldon "Interchangeabilitude" Brown
+-----------------------------------------------+
| I'll be appearing as Preposteros in |
| Gilbert & Sullivan's Thespis at M.I.T. |
| April 9-10,15-17 http://web.mit.edu/gsp/www |
+-----------------------------------------------+
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

Someone wrote:

After a 10 year break away from cycling, I recently acquired a road bike
fitted with an almost complete set of Dura Ace 7400 (8 speed STI) kit.

Since most of the roads around my home are quite hilly, I am considering
replacing the existing cassette (Dura Ace 11-23) with something in the
range of a 12-30. FYI, the front crankwheel is 51/39.

Questions:

Will I be able to fit an 8 speed Shimano cassette (made for mountain
bikes) to my rear hub?

Yes. 12-30 is pushing the envelope for your old derailer's capacity,
but will probably work with careful setup.

Will I likely need a new chain?

Yes. You should always replace the chain when installing a new cluster
anyway.

There are a number of interchangeability quirks with older Dura-Ace
stuff, and it would be worth your while to thoroughly study my Web page
on this topic: http://sheldonbrown.com/dura-ace

Sheldon "Interchangeabilitude" Brown
+-----------------------------------------------+
| I'll be appearing as Preposteros in |
| Gilbert & Sullivan's Thespis at M.I.T. |
| April 9-10,15-17 http://web.mit.edu/gsp/www |
+-----------------------------------------------+
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

On Tue, 30 Mar 2004 03:12:26 +1000, "DRS"
wrote:

Since all Deore components are designed around 9-sp what does "adjusting it
to shift the larger 8 cogs" mean?

8sp DA shifters will only move an XT rear derailleur the spacing of a
9sp cassette. With 7 clicks, you can only shift 8 of the 9
cogs...perfectly.