[followup]: Upgrading an 8 speed Shimano 105 to 9 speed.



Status
Not open for further replies.
H

Hi There

Guest
Replying to my own post...

I've done a lot more research (also with the various online cogset calculators) and I'm wondering if
it wouldn't be the most cost effective idea to put a 50x34 in front and (if I can find it) a 12-26 8
speed at the back, in this way I won't have to change derailleurs or shifters and will have plenty
of low end for those long, steep climbs.

I am wondering, though, if it -is- possible to switch just the chainrings, I've been looking around
quite a bit and while I found plenty of places selling cranksets, I've yet to figure out if it's
possible to buy the chainrings stand-alone: does anybody have any idea?
 
A shy person wrote:

"I would really like to upgrade my 8 speed setup (12-23) to a 9 speed 12-27 (lots of mountains
around here, and I like to spin, I have a 52x38 in front). My drivetrain is a 'pure' Shimano 105, as
far as I can understand I have several options (from cheapest to most expensive as far as I know):

"1- get the cogset I want (probably Ultegra), a 9 speed chain: would the shifting work? would I have
to do something about the indexing?

"2- get the cogset I want (probably Ultegra), a 9 speed chain, the ultegra 'inner ring', change the
STI shifter for the rear.

"3- spend the $$$ and just upgrade the whole drivetrain, probably also go to a 52x36 in front. I
really don't want to do this as the frame is not worth the investment (devinci vanilla alu).

> Replying to my own post...
>
> I've done a lot more research (also with the various online cogset calculators) and I'm wondering
> if it wouldn't be the most cost effective idea to put a 50x34 in front and (if I can find it) a
> 12-26 8 speed at the back, in this way I won't have to change derailleurs or shifters and will
> have plenty of low end for those long, steep climbs.

You don't need new derailers in any case, unless your old ones are damaged or worn out.

Your 105 crankset uses the 130 mm BCD (Bolt Circle Diameter) so the 38 you already have is the
smallest chainring that can fit physically without replacing the crankset.

If you were to go to one of my "Century Special" 13-30 9-speed cassettes with your present
chainrings, you'd have the same gear spacing as with a 12-27, and a slighly lower low gear than
you would have with the 34/26 option. You'd give up the 52/12 gear, but that's pretty useless for
most folks.

Upgrading to 9-speed brifters will bring your bike up to date, (8-speed stuff is pretty much
obsolete) and will also offer the possibility of converting to a triple chainwheel later on, since
9-speed brifters are all double/triple compatible.

See: http://sheldonbrown.com/harris/k7.html#9

Sheldon "Gears" Brown +---------------------------------------------------------+
| We are satisfied that there can be but little liberty | on earth while men worship a tyrant in
| heaven. | -- Robert Green Ingersoll |
+---------------------------------------------------------+

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
 
<< I'm wondering if it wouldn't be the most cost effective idea to put a 50x34 in front and (if I
can find it) a 12-26 8 speed at the back, in this way I won't have to change derailleurs or shifters
and will have plenty of low end for those long, steep climbs. >>

You can't mount a 34T chainring on a 105 double crankset-38T is the smallest chainring that will
fit. An 8 sp cassette with a 26T max cog will give you a gear close to a 27T-not much difference,
esp. when used with the 38T front. If you do upgrade to 9 sp, you will need a minimum of new 9 sp
right STI shifter, chain, cassette. Not sure about the rear derailleur.
 
On 18 Nov 2003 07:50:57 -0800, Hi there <[email protected]> wro= te:

> I'm wondering if it wouldn't be the most cost effective idea to put a 50x34 in front and (if I can
> find it) a 12-26 8 speed at the back...

50x34 up front requires a different crank, as has been noted already. Y= ou =

may be able to find a replacement crank that uses the same BB as your =

current crank.

SRAM makes a 12-26 8spd cassette. =

(http://www.sram.com/road/cassettes/pg850.asp). I currently have one on=
=

my racing bike which runs 8-speed Shimano components.

-- =

Dave dvt at psu dot edu
 
[email protected] (Hi there) wrote in message
news:<[email protected]>...
> Replying to my own post...
>
> I've done a lot more research (also with the various online cogset calculators) and I'm wondering
> if it wouldn't be the most cost effective idea to put a 50x34 in front and (if I can find it) a
> 12-26 8 speed at the back, in this way I won't have to change derailleurs or shifters and will
> have plenty of low end for those long, steep climbs.
>
> I am wondering, though, if it -is- possible to switch just the chainrings, I've been looking
> around quite a bit and while I found plenty of places selling cranksets, I've yet to figure out if
> it's possible to buy the chainrings stand-alone: does anybody have any idea?

You didn't say what kind of crank you have. If your crank has a 110mm bcd, then yes, you can go as
low as a 34t inner chainring. If its 130mm bcd (shimano standard), then 38t is the smallest. If its
a Campy crank (135mm bcd), then 39t is the smallest.

With regard to purchasing just chainrings, there are many places, including your LBS, that sells
them, one example:

http://www.sheldonbrown.com/harris/chainrings.html
 
[email protected] (Hi there) wrote in message
news:<[email protected]>...
> Replying to my own post...
>
> I've done a lot more research (also with the various online cogset calculators) and I'm wondering
> if it wouldn't be the most cost effective idea to put a 50x34 in front and (if I can find it) a
> 12-26 8 speed at the back, in this way I won't have to change derailleurs or shifters and will
> have plenty of low end for those long, steep climbs.
>
> I am wondering, though, if it -is- possible to switch just the chainrings, I've been looking
> around quite a bit and while I found plenty of places selling cranksets, I've yet to figure out if
> it's possible to buy the chainrings stand-alone: does anybody have any idea?

You can get separate chainrings and install them. For example, see
http://www.sheldonbrown.com/harris/chainrings.html. That said there are a couple of caveats with
your proposed setup. You say you want a 50-34 front. Being able to get that depends on your cranks,
and the bolt pattern used to attach the rings to the crank arms. If you have a Shimano or Campy road
crank, forget it. The Shimano road cranks have a 130 BCD, and the smallest ring is 38T. Campy uses
135 BCD, and the smallest ring is 39T. You are in fat city if you have a crankset that uses the old,
and apparently being revived, 110/74 BCD. With 110 you can get rings as small as 34T; this is how
Tyler Hamilton got his mountain crankset that had a 34T inner this past summer; he was using an FSA
crankset that is
110/74. Now if we can get manufacturers to be reasonable and standardize on 110 ... naww,
never happen.

- rick
 
On you webpage listed below, it says "The only parts that are different in any important way between
the 8- and 9-speed systems are the shift control levers." Does this mean an 8 speed chain will work
with a 9 speed cassette ?

On Tue, 18 Nov 2003 11:58:05 -0500, Sheldon Brown wrote:
> Upgrading to 9-speed brifters will bring your bike up to date, (8-speed stuff is pretty much
> obsolete) and will also offer the possibility of converting to a triple chainwheel later on, since
> 9-speed brifters are all double/triple compatible.
>
> See: http://sheldonbrown.com/harris/k7.html#9
>
> Sheldon "Gears" Brown
 
I wrote:

>>Upgrading to 9-speed brifters will bring your bike up to date,(8-speed stuff is pretty much
>>obsolete) and will also offer the possibility of converting to a triple chainwheel later on,
>>since 9-speed brifters are all double/triple compatible.

A shy person top-posted:

> On you webpage listed below, it says "The only parts that are different in any important way
> between the 8- and 9-speed systems are the shift control levers." Does this mean an 8 speed chain
> will work with a 9 speed cassette ?

Maybe, but you might as well get a 9-speed one to be on the safe side. You should always replace the
chain when installing a new cassette in any case.

Sheldon "Only $3 More" Brown +--------------------------------------------------------------+
| A: Because it reverses the logical flow of conversation. |
| Q: Why is top posting frowned upon? |
+--------------------------------------------------------------+ 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
 
"Hi there" <[email protected]> wrote in message
news:[email protected]...
> Replying to my own post...
>
> I've done a lot more research (also with the various online cogset calculators) and I'm wondering
> if it wouldn't be the most cost effective idea to put a 50x34 in front and (if I can find it) a
> 12-26 8 speed at the back, in this way I won't have to change derailleurs or shifters and will
> have plenty of low end for those long, steep climbs.

A cassette with a 32 (or even 34) will give you the same result. It'll mean a new rear derailer, but
LX rears are very nice, and pretty cheap. The advantage of this approach is that you can switch
cassettes easily for different terrain.
 
Status
Not open for further replies.

Similar threads

S
Replies
7
Views
360
Road Cycling
Chicago Paddling-Fishing
C
M
Replies
11
Views
573
Cycling Equipment
Mike Rocket J Squirrel
M
H
Replies
14
Views
473
O
R
Replies
45
Views
1K
Road Cycling
Jasper Janssen
J