7 to 8 Speed

"ChronoFish" <[email hidden]> wrote in message
news:ScKPc.644$73.115@lakeread04...

Quoted message said:

Hello,

Right - I'm WAY behind the technology curve. But it all
comes down to money and priorities.....

I currently have a 1996/1997 Cannondale R300 that has been
slowly "upgraded" and transformed into a tri bike over time.

The rims on the wheels are grooved and should probably be
replaced at the end of the season if not sooner. While
doing so I would like to move up to an 8-speed cassette.

Why 8? The thought is that it would give me one more gear
choice while allowing me to keep my current drive train. Is
this the correct assumption?

The current setup of a older 105 rear derailleur with
bar-end shifters mounted on aerobars in friction setting
(rather than STI) works quite well I am very happy with it.
However the 11-21 cluster is a bit of a challenge (for me)
on steeper hills.

I was hoping to focus more of my money on the wheels -
something like a pair of Aerospokes with an 8-speed (11-26
or something similar) without having to upgrade the
rear-derailleur, chain, and therefore crankset (in other
words the entire drivetrain).

Is there any reason why I couldn't do this?

Thanks!
-CF

No reason that I can think of as long as you keep your shifters in friction
mode. By upgrading to an 8-speed rear wheel you can later upgrade to a
9-speed if desired. If for any reason you want to stay with 7-speed, there
is a spacer available that will allow a 7-speed cassette to be used on an
8-speed wheel.

ChronoFish said:

Why 8? The thought is that it would give me one more gear
choice while allowing me to keep my current drive train. Is
this the correct assumption?

Yes, as long as the shifters will cut it, the rest will follow (unless
it's Dura-Ace) up to 8sp or 9 sp (if you switch chains).
8sp and 9sp use the same cassette width (wider than 7 sp) so if you feel
the need for 9sp later on, then you just have to buy a new cassette and
chain.
Another idea is to use 8 sprockets of a 9sp cassette on a 7sp hub,
this eliminates the possible problem below. However, this means getting
a new wheel with a 7sp hub which probably isn't that easy nowadays, and
a 9sp chain.

For more info, see this article by Sheldon Brown:
http://www.sheldonbrown.com/k7.html#up7

Quoted message said:

Is there any reason why I couldn't do this?

Possibly one reason, the hubs for 8sp and 9sp are a bit wider than the
7sp ones, therefore the the rear dropouts will not fit out of the box,
so you have to pry them apart (126mm vs 130 mm) a bit.
If it's a non-steel frame (sorry, not familiar with your bike), this
may damage the frame. However, many have gone 7->8/9 without large
problems.

For more info, see this article by Sheldon Brown:
http://www.sheldonbrown.com/frame-spacing.html

/Tomas

--
Caps and foobar are normally not parts of my address.

"ChronoFish" <[email hidden]> wrote in message news:<ScKPc.644$73.115@lakeread04>...

Quoted message said:

Hello,

Right - I'm WAY behind the technology curve. But it all
comes down to money and priorities.....

I currently have a 1996/1997 Cannondale R300 that has been
slowly "upgraded" and transformed into a tri bike over time.

<snip>

Quoted message said:

I was hoping to focus more of my money on the wheels -
something like a pair of Aerospokes with an 8-speed (11-26
or something similar) without having to upgrade the
rear-derailleur, chain, and therefore crankset (in other
words the entire drivetrain).

Is there any reason why I couldn't do this?

Not in particular. You should probably replace the chain when you
replace the cassette, just as a matter of course. Double-check the
spacing of your rear triangle- if it's 126mm, you may have trouble
fitting the Aerospoke rear wheel. See
http://www.sheldonbrown.com/gloss_sp-ss.html#spacing .

Jeff

ChronoFish said:

I currently have a 1996/1997 Cannondale R300 that has been
slowly "upgraded" and transformed into a tri bike over time.

The rims on the wheels are grooved and should probably be
replaced at the end of the season if not sooner. While
doing so I would like to move up to an 8-speed cassette.

Why 8? The thought is that it would give me one more gear
choice while allowing me to keep my current drive train. Is
this the correct assumption?

Yes, but the same is true of 9. 8-speed is a bit of a dead end, and I
would advise against it.

Quoted message said:

The current setup of a older 105 rear derailleur with
bar-end shifters mounted on aerobars in friction setting
(rather than STI) works quite well I am very happy with it.
However the 11-21 cluster is a bit of a challenge (for me)
on steeper hills.

I was hoping to focus more of my money on the wheels -
something like a pair of Aerospokes with an 8-speed (11-26
or something similar) without having to upgrade the
rear-derailleur, chain, and therefore crankset (in other
words the entire drivetrain).

You don't need to change that much stuff.

To convert to 9-speed friction, all you need is the new rear wheel with
a 9-speed cassette and suitable chain. (You should always replace the
chain when you install a new cassette.)

If you want go to with indexing, you'll also need to replace the shifters.

The 9-speed Dura-Ace bar-end shifters had been in very short supply, but
we just received a large shipment of them.

See: http://sheldonbrown.com/harris/shifters.html#dura

You don't need to replace derailers or chainrings, the ones you have
will work fine.

Sheldon "Upgrades" Brown
+-----------------------------------------------------+
| We can complain because rose bushes have thorns, |
| or rejoice because thorn bushes have roses. |
| --Abraham Lincoln |
+-----------------------------------------------------+
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

Tomas Bystrom <[email hidden]> wrote in message news:<[email hidden]>...

Quoted message said:

ChronoFish said:

Why 8? The thought is that it would give me one more gear
choice while allowing me to keep my current drive train. Is
this the correct assumption?

Yes, as long as the shifters will cut it, the rest will follow (unless
it's Dura-Ace) up to 8sp or 9 sp (if you switch chains).

......

Quoted message said:

Quoted message said:

Is there any reason why I couldn't do this?

Possibly one reason, the hubs for 8sp and 9sp are a bit wider than the
7sp ones, therefore the the rear dropouts will not fit out of the box,
so you have to pry them apart (126mm vs 130 mm) a bit.
If it's a non-steel frame (sorry, not familiar with your bike), this
may damage the frame. However, many have gone 7->8/9 without large
problems.

Thanks for the info - I will be reading it shortly. The Cannondale is
aluminum and the drop-outs measure (with the current wheel attached)
at about 127mm on the inside.

Since you mention being able to go up to 9spd - wouldn't I have to not
only switch chains but also the front chain-rings (and then probably
the crankset and front derailure...)?

- CF

Sheldon Brown said:

If you want go to with indexing, you'll also need to replace the shifters.

Pardon my ignorance but what's indexing?

TIA,
Brad

ChronoFish said:

The Cannondale is aluminum and the drop-outs measure (with the current
wheel attached) at about 127mm on the inside.

Then I would guess that changing to 130mm won't be that big of a deal,
just take it easy and gently pry the dropouts apart when installing the
new wheel.

Quoted message said:

Since you mention being able to go up to 9spd - wouldn't I have to not
only switch chains but also the front chain-rings (and then probably
the crankset and front derailure...)?

The difference in chainwidth is slight (but still enough to make or
break correct 9sp shifting), so your chain rings won't cause any
trouble. There's nothing special about a "9sp crankset", and they
maintain the bolt circle so newer chain rings will fit your current
crankset, if the need to change arises.

So, to sum up what you need to do:
1. Get a wheel with (8/)9sp hub, cassette of your liking (Shimano stocks
quite a few price levels, the most expensive focus on lighter weight and
have nifty tech features - there is not much difference in performance
though, personally I'd probably go for the level of the 105 group), and
a chain.
2. Install the wheel, it's OK to use some force but do it smoothly.
Stop to think/feel if you're unsure. As said, it's most likely not a
problem at all, but better safe than sorry.
3. Install chain, cut it to the appropriate length.
4. Adjust the hi and lo stop screws on your rear derailer so you'll
reach all 9 gears, but there shouldn't be more room than that (derailers
and spokes don't mix very well... :-).
5. Enjoy your new gear!

/Tomas

--
Caps and foobar are normally not parts of my address.

I have an extra Shimano 600 rear derailleur (8 speed) if you need one.
It's in good condition with low mileage. $20 shipped.

"ChronoFish" <[email hidden]> wrote in message news:<ScKPc.644$73.115@lakeread04>...

Quoted message said:

Hello,

Right - I'm WAY behind the technology curve. But it all
comes down to money and priorities.....

I currently have a 1996/1997 Cannondale R300 that has been
slowly "upgraded" and transformed into a tri bike over time.

The rims on the wheels are grooved and should probably be
replaced at the end of the season if not sooner. While
doing so I would like to move up to an 8-speed cassette.

Why 8? The thought is that it would give me one more gear
choice while allowing me to keep my current drive train. Is
this the correct assumption?

The current setup of a older 105 rear derailleur with
bar-end shifters mounted on aerobars in friction setting
(rather than STI) works quite well I am very happy with it.
However the 11-21 cluster is a bit of a challenge (for me)
on steeper hills.

I was hoping to focus more of my money on the wheels -
something like a pair of Aerospokes with an 8-speed (11-26
or something similar) without having to upgrade the
rear-derailleur, chain, and therefore crankset (in other
words the entire drivetrain).

Is there any reason why I couldn't do this?

Thanks!
-CF