Bicycle Mechanics - Newbie upgrade question

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View Full Version : Newbie upgrade question


NSimmons7
06-06-03, 11:47 AM
New to the group. Sorry if this is an old question for those veteran mechanics out there!

I have an old (about 10 years) Giant carbon frame bike that I'd like to upgrade to 9 speed 105 STI with a triple crank.

If I am planning on upgrading everything (FD/RD/shifters/crank/BB/cassette), is there any reason this is impossible (i.e., any geometric limitations on older frames)?

I also know that some suggest to sell this bike and buy a new one with the components I want.

The reason for wanting to do this is:

1. Improve my limited mechanical skills.
2. Finding a low priced carbon frame isn't terribly easy.
3. Sentimental reasons. I could never sell her.

Any thoughts are appreciated!

Nathan


a2psyklnut
06-06-03, 11:57 AM
There shouldn't be any problems. You will however need to verify the clamp diameter for the front derailleur unless of course you have a special clamp due to the carbon tubes. You will also need to know if it's a top swing or bottom swing and top pull or bottom pull. As a mechanic for many years, I still can't tell you which is which without looking it up to verify.

Running a triple will require a longer bottom bracket.

Oh, the most important potential problem I can imagine is the spacing of the rear end. 9 speed hubs now require 130mm spacing. If your frame is an older 7 speed it may not work and could cause a potential for damage trying to force a 130mm hub into the frame!

L8R

dwatson
06-06-03, 12:39 PM
I upgraded a Speicalized Epic carbon a few years back. Like a2psyklnut said the rear spacing is the only draw back. If need be, you can try and find an 8 speed hub. Good luck.


Chasbo
06-06-03, 04:14 PM
If your Giant carbon bike is a Cadex, you really wont be able to upgrade easily to 9 speed. That model was 3 tubes carbon with a rear end made of alloy. The spacing is fine for 7 speed, but the 8/9 speed stuff requires 130mm spacing and alloy rear triangles dont like to be widened. Especially when they are 10 years old, an age when alloy frames are often riddled with micro cracks. It would suck to put the cash into a bunch of 9 speed stuff and then have your frame fail. I believe that the fork on that model was also an alloy unit. 10 years is a long time for an alloy fork, may be time to think of retiring it.

Chuck

John E
06-07-03, 03:06 PM
If you indeed have a 126 or 128mm rear triangle which cannot or should not be spread, consider buying a 9-speed chain and freewheel and installing only 8 cogs. (I believe Sheldon talks about this somewhere in his website.)

sch
06-07-03, 10:48 PM
Eight speed hubs have the same width as 9spd hubs. Borrow
a 9 spd hub and see how easy it is to place in the frame.
Make sure it is a road wheel as ATB are 135mm, way too wide.
I have done this with an old steel frame and it was hard to
spread, had to use one foot, one hand and manipulate the hub
in place with the other. The other frame was a Titan pure Ti
frame and it was easy to spread. If the old frame had down
tube shifters the boss the shifters attach to that wraps around
the tube can be a site of attachment for cable guides for the STI
shifters. The plastic cable guide that Shimano ships with their
shifter sets can be screwed to the bottom of the bottom bracket
easily. The caution about glue joints with carbon and alloy combo frames - they do tend to come apart with time and the stress of spreading may or may not exacerbate or cause this.
Steve

dexmax
06-08-03, 06:27 AM
Originally posted by sch
Eight speed hubs have the same width as 9spd hubs. Borrow
a 9 spd hub and see how easy it is to place in the frame.
Make sure it is a road wheel as ATB are 135mm, way too wide.
I have done this with an old steel frame and it was hard to
spread, had to use one foot, one hand and manipulate the hub
in place with the other. The other frame was a Titan pure Ti
frame and it was easy to spread.

I think it is safe to spread those rear triangles(although people say never do it). I have done it in the past... Just make sure you don't use the 135mm axles. yes the 5mm difference might be small, but it is very hard to spread it 5mm more, especially if your frame is designed for 126mm axles...

Chasbo
06-08-03, 07:32 AM
Titanium and steel frames are ok for spreading guys. The problem with alloy frames, especially OLD alloy frames is that they are prone to failure even without the spreading. Widening the frame like you suggest is a sure ticket to premature failure. The stays on the giant are super thin AND glued and will not take this type of abuse. Even if you manage to spread them without breaking them, you will still have a weaker overall rearend. Try to imagine a 40mph plus descent on such a rear end. An alloy bike of this era should just be left alone. Money is better spent on a new frame to hang the new parts.

Chuck

Phatman
06-08-03, 10:53 AM
Originally posted by John E
If you indeed have a 126 or 128mm rear triangle which cannot or should not be spread, consider buying a 9-speed chain and freewheel and installing only 8 cogs. (I believe Sheldon talks about this somewhere in his website.)

That is a really cool idea. Also, Sheldon had some NOS 7 speed 105 freehubs that look much better then the new ones, IMO.

That is what you were suggesting, right? "Ultra" 8 on a 7 speed hub?

orguasch
06-08-03, 02:46 PM
my Pinarello Treviso vintage 1990, original cogs is 7, but it can take the campy 10 no problem, no need to expand the frame, the rear hubs are the one shrinking and really there is no need to expand your bike frame to take the 10