Road cassettes with MTB group?

My commuter has 27sp Deore running gear
with an 11-32 (9 speed) cassette on the back.
I find this too spread out and would like to
put on something like a 12-25 (or even 12-23)
that is available for 9sp shimano road systems.

So, are Shimano road/MTB 9 speed cassettes
compatible? I imagine that I might need to
modify chain length but I was thinking of the
indexing.

Cheers,
DeF.

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DeF Wrote:
My commuter has 27sp Deore running gear
with an 11-32 (9 speed) cassette on the back.
I find this too spread out and would like to
put on something like a 12-25 (or even 12-23)
that is available for 9sp shimano road systems.


I cant answer your question, but are you sure you want to give up that
11 tooth? I was thinking Sora 11-23 on my mtb/commute.. but its hard
to find 8 spd stuff these days... opted for a 11-28.. I even used the
granny/28 today up Yarra St..

cheers,
GPL
:easy ride day:


--
gplama

DeF wrote:
So, are Shimano road/MTB 9 speed cassettes
compatible?
Yep. Also SRAM are compatible.

I imagine that I might need to modify chain length but I was
thinking of the indexing.

You will need to shorten the chain. Indexing will be the same if you
stay at the same number of speeds, that is 9. If you were going the
other way, say putting a 34 "mountain" gear on a "road" bike you may
need a longer armed rear derailleur.

On 2006-02-13, gplama (aka Bruce)
was almost, but not quite, entirely unlike tea:
DeF Wrote:
My commuter has 27sp Deore running gear
with an 11-32 (9 speed) cassette on the back.
I find this too spread out and would like to
put on something like a 12-25 (or even 12-23)
that is available for 9sp shimano road systems.

I cant answer your question, but are you sure you want to give up that
11 tooth? I was thinking Sora 11-23 on my mtb/commute.. but its hard
to find 8 spd stuff these days... opted for a 11-28.. I even used the
granny/28 today up Yarra St..

cheers,
GPL
:easy ride day:

Next you'll be telling us you've installed a triple!

--
TimC
According to the latest official figures, 43% of all statistics
are totally worthless.

"Evan" evan@thegroup wrote in message
...
DeF wrote:
So, are Shimano road/MTB 9 speed cassettes
compatible?
Yep. Also SRAM are compatible.

I imagine that I might need to modify chain length but I was
thinking of the indexing.

You will need to shorten the chain. Indexing will be the same if you stay
at the same number of speeds, that is 9. If you were going the other way,
say putting a 34 "mountain" gear on a "road" bike you may need a longer
armed rear derailleur.

Hi There,

The cassettes are compatible, no problems. I run a 12 - 23 on my MTB for
commuting, SRAM should be fine as I alternate it on my road bike.

However, not sure why you would shorten the chain as the range of speeds and
teeth etc will be with the range offered by the old MTB cassette. That is
you could change the chain length but don't have to, as you may wish to
change back to a MTB cassette at some later date. Perhaps someone here can
explain why you would Need to change chain length, cos I can't see it.

Kev

Kev wrote:

However, not sure why you would shorten the chain as the range of speeds and
teeth etc will be with the range offered by the old MTB cassette.

My mistake. Kev is correct. No need to shorten the chain.

TimC wrote:
On 2006-02-13, gplama (aka Bruce)
was almost, but not quite, entirely unlike tea:
DeF Wrote:
My commuter has 27sp Deore running gear
with an 11-32 (9 speed) cassette on the back.
I find this too spread out and would like to
put on something like a 12-25 (or even 12-23)
that is available for 9sp shimano road systems.

I cant answer your question, but are you sure you want to give up that
11 tooth? I was thinking Sora 11-23 on my mtb/commute.. but its hard
to find 8 spd stuff these days... opted for a 11-28.. I even used the
granny/28 today up Yarra St..

cheers,
GPL
:easy ride day:

Next you'll be telling us you've installed a triple!

He's got a 2 stroke motor on the back.

TimC Wrote:

Next you'll be telling us you've installed a triple!


MTB comes with one standard Waiting for the '07 XT/XTR stuff to
come out with only a double.. granny is dead..


cheers,
GPL


--
gplama

gplama wrote:
DeF Wrote:
My commuter has 27sp Deore running gear
with an 11-32 (9 speed) cassette on the back.
I find this too spread out and would like to
put on something like a 12-25 (or even 12-23)
that is available for 9sp shimano road systems.


I cant answer your question, but are you sure you want to give up that
11 tooth? I was thinking Sora 11-23 on my mtb/commute.. but its hard
to find 8 spd stuff these days... opted for a 11-28.. I even used the
granny/28 today up Yarra St..

cheers,
GPL
:easy ride day:



Well, I've only *very rarely* used the 11 thus far. I would
much rather have more ratios to choose from in the middle
of the range. In the end, I've gone for a tiagra 12-23
and based on other posts (ta, Kev), I'll leave the chain
length as is (I'm also replacing this). If the set up is
not quite right, I'll just wait until I wear it out and
get another one! Brilliant!

The new set up 12-23 with a 21-32-44 front gives me a nice
spread of 60.2 to 95.3 inch over 7 gears on the "big" (as
a roadie, I find it hard to call 44 'big') ring. Perth is
pretty flat and I've got the middle ring doing 39.6 to 59.4.
The granny should get me up any slope, with any load against
any headwind, at least on the road.

Now I need to get home to put it all on and go for a ride..

DeF.


PS My spell checker wants to replace gplama with "eggplant". WTF?

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