8 speed STI levers

It will work okay with the 7/8 spd combo as the spacing between the individual gears on the cassette
is the same (the 8-spd cassette is one gear wider) but not an 8/9 combo as the spacing is smaller
with the 9 spd. Basically the 8-spd cassette and 9-spd cassettes are the same width, it's just the
spacing between gears which differs - this is why the 9 spd chain is narrower etc etc.

The 9 spd STI levers are designed to index the smaller distance between gears. It's a pain but
that's life....!!

FWIW - you an use many 8-spd components with 9-spd set-ups but not the STIs.

Boz

"Rik O'Shea" <[email hidden]> wrote in message
"]news:[email hidden]...

Quoted message said:

I recall in an earlier thread a poster requested information on replacing an 8 speed Shimano
Ultegra STI lever. These are no longer manufactured - only 9 speed is available. His concern was
the cost of an upgrade to a complete 9 speed setup and was quite happy with his 8 speed casette,
front & read derailleur and so on. The general concensus was that his only option was the 8 speed
Sora STI lever.

I would like to suggest that you can use an 9 speed STI lever with an 8 speed cassette and rear &
front derailleur set up with the following reasoning:

It is the cable tension connecting the STI lever to the rear derailleur that governs the amount
of travel associated with the rear derailleur for each click of the STI lever. Once you have
adjusted the rear derailleur adjustment bolt to give the correct cable tension so that the chain
moves from the 8th (top sprocket) to the 7th sprocket then everything should be ok. Each
subsequent click of the lever will move the chain up to the next sprocket. When the chain reaches
the 1st sprocket (lowest sprocket) you still in theory have one click left on the 9 speed STI
lever. However you will not be able to click the lever as the rear derailleur is prevented from
travelling any further by virtue of the inward adjustment bolt and this prevents you from using
that extra 9th click.

Now I have not verified this with a 9 speed STI/8 Speed cassette combination as I still only use 8
speed STI levers but I previously used an 8 speed SIS down tube lever with a 7 speed cassette
using the same principle without any problems.

Can anyone suggest why my theory on 9 speed STI/8 speed cassette would not work ?

R

Rik O'Shea said:

It is the cable tension connecting the STI lever to the rear derailleur that governs the amount of
travel associated with the rear derailleur for each click of the STI lever.

No it's not. It is the ratchet or cam or whatever mechanism is used inside the shifter that governs
the amount of cable pulled per click.

Altering cable tension only tunes the position of the derailleur. It doesn't alter the amount it
moves per click. So even if you get it in the correct position for one gear, it will be out with the
next click.

9-speed spacing is different to 8-speed so either different shifters are required or some
alternative solution. It can't be done simply by adjusting the cable.

~PB

[email hidden] (Rik O'Shea) wrote in message
news:<[email hidden]>...

Quoted message said:

I would like to suggest that you can use an 9 speed STI lever with an 8 speed cassette and rear &
front derailleur set up with the following reasoning:

It is the cable tension connecting the STI lever to the rear derailleur that governs the amount
of travel

----------------

nope... its not the tension, its the travel per-click

the 8 and 9 speed shifters move the cable different amounts per click. its close, but not close
enough for good shifting over the whole range. the 8 and 9 speed cassettes are the same overall
width; hence the spacing is closer, hence the shifters are different. So, you need at least a new
shifter, cassette, and chain to move from 8 to 9 speed.

I lucked out and was able to find a used 8sp shimano600 set for $40. Next upgrade I'll probably have
to get shifter, cassette, chain... for best results I might even think about crankset since the
front spacing with the narrow chain would shift better with official 9sp gear, but that would be far
less sensitive. at that point though, its not much more to get a new bike and convert the old frame
to a fixed-gear or something else. 😉

d

"Rik O'Shea" <[email hidden]> wrote in message
"]news:[email hidden]...

Quoted message said:

I recall in an earlier thread a poster requested information on replacing an 8 speed Shimano
Ultegra STI lever. These are no longer manufactured - only 9 speed is available. His concern was
the cost of an upgrade to a complete 9 speed setup and was quite happy with his 8 speed casette,
front & read derailleur and so on. The general concensus was that his only option was the 8 speed
Sora STI lever.

You don't need a "complete 9 speed setup." The derailers work the same. All you need is a 9sp
shifter, a 9sp cassette, and a 9sp chain. The shifter is the expensive part. When it comes time to
replace a shifter, spend the extra 30-40 bucks for a 9sp cassette/chain at the same time, and be
done with it.

Quoted message said:

I would like to suggest that you can use an 9 speed STI lever with an 8 speed cassette and rear &
front derailleur set up with the following reasoning:

It is the cable tension connecting the STI lever to the rear derailleur that governs the amount
of travel associated with the rear derailleur for each click of the STI lever. Once you have
adjusted the rear derailleur adjustment bolt to give the correct cable tension so that the chain
moves from the 8th (top sprocket) to the 7th sprocket then everything should be ok. Each
subsequent click of the lever will move the chain up to the next sprocket. When the chain reaches
the 1st sprocket (lowest sprocket) you still in theory have one click left on the 9 speed STI
lever. However you will not be able to click the lever as the rear derailleur is prevented from
travelling any further by virtue of the inward adjustment bolt and this prevents you from using
that extra 9th click.

Now I have not verified this with a 9 speed STI/8 Speed cassette combination as I still only use 8
speed STI levers but I previously used an 8 speed SIS down tube lever with a 7 speed cassette
using the same principle without any problems.

Can anyone suggest why my theory on 9 speed STI/8 speed cassette would not work ?

It very well might, but there's usually no reason to do it. People ran 7sp cassettes with 8sp setups
because 8sp cassettes wouldn't fit on 7sp wheels. But 8sp and 9sp wheels are the same. If you have
an 8sp wheel you can just slap on a 9sp cassette and have everything work perfectly.

Cassettes are available as cheap as $15-16. Shimano HG50, and SRAM cassettes work just fine.
Nashbar/Performance usually have a few on sale, and package deals with chains as well.

Matt O.

[email hidden] (Rik O'Shea) wrote in message
news:<[email hidden]>...

Quoted message said:

I would like to suggest that you can use an 9 speed STI lever with an 8 speed cassette and rear &
front derailleur set up with the following reasoning:

It is the cable tension connecting the STI lever to the rear derailleur that governs the amount
of travel associated with the rear derailleur for each click of the STI lever. Once you have
adjusted the rear derailleur adjustment bolt to give the correct cable tension so that the chain
moves from the 8th (top sprocket) to the 7th sprocket then everything should be ok. Each
subsequent click of the lever will move the chain up to the next sprocket. When the chain reaches
the 1st sprocket (lowest sprocket) you still in theory have one click left on the 9 speed STI
lever. However you will not be able to click the lever as the rear derailleur is prevented from
travelling any further by virtue of the inward adjustment bolt and this prevents you from using
that extra 9th click.

Now I have not verified this with a 9 speed STI/8 Speed cassette combination as I still only use 8
speed STI levers but I previously used an 8 speed SIS down tube lever with a 7 speed cassette
using the same principle without any problems.

With each shift, a 9 speed STI shifter pulls and retracts less cable than an 8 speed Ultegra STI. As
a result, the amount of 8 speed rear derailleur movement is less. So it would not work.

It worked for you with 8 speed indexed shifters on a 7 speed cassette because the amount of cable
pull between 8 and 7 speed indexed shifters is the same. And the spacing between rear cogs is
(almost) the same.

Tom

Quoted post said:

Originally posted by Thomas Reynolds
[email hidden] (Rik O'Shea) wrote in message
news:<[email hidden]>...

Quoted message said:

I would like to suggest that you can use an 9 speed STI lever with an 8 speed cassette and rear &
front derailleur set up with the following reasoning:

It is the cable tension connecting the STI lever to the rear derailleur that governs the amount
of travel associated with the rear derailleur for each click of the STI lever. Once you have
adjusted the rear derailleur adjustment bolt to give the correct cable tension so that the chain
moves from the 8th (top sprocket) to the 7th sprocket then everything should be ok. Each
subsequent click of the lever will move the chain up to the next sprocket. When the chain reaches
the 1st sprocket (lowest sprocket) you still in theory have one click left on the 9 speed STI
lever. However you will not be able to click the lever as the rear derailleur is prevented from
travelling any further by virtue of the inward adjustment bolt and this prevents you from using
that extra 9th click.

Now I have not verified this with a 9 speed STI/8 Speed cassette combination as I still only use 8
speed STI levers but I previously used an 8 speed SIS down tube lever with a 7 speed cassette
using the same principle without any problems.

With each shift, a 9 speed STI shifter pulls and retracts less cable than an 8 speed Ultegra STI. As
a result, the amount of 8 speed rear derailleur movement is less. So it would not work.

It worked for you with 8 speed indexed shifters on a 7 speed cassette because the amount of cable
pull between 8 and 7 speed indexed shifters is the same. And the spacing between rear cogs is
(almost) the same.

Tom

Shimano Center-to-Center 7 speed spacing is 5 mm, 8 speed is 4.8 mm, and 9 speed is 4.34 mm.
You can buy a Shimano 9 speed bar end shifter kit for around $46 street price. You can shift 8 speed in the friction mode.
When you buy your next chain and cassette, assuming it's a 9 speed, you switch to index mode.
If you really want to stay with 8 speed, there are a couple of other alternatives:
Sachs 8 speed (not Campy) brifters use 4.8 mm indexing.
Shimano 8 speed Bar ends also use 4.8 mm indexing.

The space between the center of each sprocket is more or less the same for 7 and 8 speed, but for
9 speed, it certainly is less. You cannot use a 9 speed STI lever with an 8 speed cassette using
your example.

Dave