7sp to 9sp conversion

[Bob From Conshy]

I have an 9 yr old, 7sp MTB w/ LX components. It's got a newer, high-end fork. No rust (cro-moly) or
major frame damage. However, the shifters, chain, freewhell (not cassette?) and chainrings
(biopacing) are badly worn and in need of replacing.

I went to my LBS to replace the shifters (rapidfire) and my only option in 7sp was Alivio. I fear
that I'll have to work my way down the Shimano foodchain with all my replacement parts. To avoid
this and get 9 speeds, I'm concidering a wholesale upgrade. Outside of the issue of whether this is
advisable or cost effective, I have some questions:

Is this upgrade possible? Is there anything about the bottom bracket width or rear wheel
drop-outs that prevent installing new 9sp components? What should I check or measure before
undertaking this endevore?

Is it advisable to go any lower than LX? Deore? I don't race or even ride super hard. However, I'm
used to the LX components working well and being super reliable. With the number of parts
necessary to effect the upgrade, I could use the dollar savings - as long as I'm not left with
junky/clunky stuff.

Are there cheaper/better alternatives than Shimano for some of the parts? I'm not interested in any
of the grip-shift variants.

Is the following list of parts complete? back wheel, cassette, front and rear deralliers, chain,
bottom bracket, crank, and shifters

 

[Ajames54]

On Tue, 3 Jun 2003 18:56:07 -0400, "Bob from Conshy" <[email protected]> wrote:

>I have an 9 yr old, 7sp MTB w/ LX components. It's got a newer, high-end fork. No rust (cro-moly)
>or major frame damage. However, the shifters, chain, freewhell (not cassette?) and chainrings
>(biopacing) are badly worn and in need of replacing.
>
>I went to my LBS to replace the shifters (rapidfire) and my only option in 7sp was Alivio. I fear
>that I'll have to work my way down the Shimano foodchain with all my replacement parts. To avoid
>this and get 9 speeds, I'm concidering a wholesale upgrade. Outside of the issue of whether this is
>advisable or cost effective, I have some questions:
>
>Is this upgrade possible? Is there anything about the bottom bracket width or rear wheel drop-outs
>that prevent installing new 9sp components? What should I check or measure before undertaking this
>endevore?
>
>Is it advisable to go any lower than LX? Deore? I don't race or even ride super hard. However, I'm
>used to the LX components working well and being super reliable. With the number of parts
>necessary to effect the upgrade, I could use the dollar savings - as long as I'm not left with
>junky/clunky stuff.
>
>Are there cheaper/better alternatives than Shimano for some of the parts? I'm not interested in any
>of the grip-shift variants.
>
>Is the following list of parts complete? back wheel, cassette, front and rear deralliers, chain,
>bottom bracket, crank, and shifters
>
>
>
The nine speed upgrade is possible the only thing you need to add to your list is re-spacing the
rear drop outs ...

You probably don't need to replace the rear wheel if it currently is a Cassette (and '94 LX would be
a cassette) you can get a 9 speed cassette body and a 9 speed axle then all you need to do is
re-dish the wheel .. though the cost comparison may end up favoring the replacement.

FWIW I don't think you will need to replace your cranks, bottom bracket or your front derailleur,
chain rings are still available if you look. Someone will certainly correct me if I'm wrong but I
don't think there are any real issues running a 9 speed chain on older front rings.

Personally I would look around other shops for new-old-stock 7 speed shifters the ones around here
have them...

www.sheldonbrown.com

lists lots of options and even has parts available...

 

[Jasper Janssen]

On Tue, 3 Jun 2003 18:56:07 -0400, "Bob from Conshy" <[email protected]> wrote:

[worn drivetrain, upgrade 7 to 9 for availability of higher end components]

>Is the following list of parts complete? back wheel, cassette, front and rear deralliers, chain,
>bottom bracket, crank, and shifters

More like overcomplete. The only thing you need to replace on the front are the chainrings,
assuming your cranks do have replaceable chainrings (and given that they're high end stuff, they
should). You might also be able to get away with using the same rear derailler. For that matter,
the left shifter for the front doesn't need to change either, though it might look, feel and
operate funny if you have completely different types left and right. You might also want to replace
the derailler cables, when you're at it. Use high quality compressionless plastic lined housings
and good quality inner cables.

Depending on what particular type of hub you have, you might be able to replace the 7 speed cassette
body with an 8/9 speed one, thus saving yourself the cost and time of rebuilding the wheel. This can
almost always be done, if it is a freehub and not a freewheel type. Freehub will usually have a
bulge in the hub at the right side, that containts the freewheeling mechanism, whereas a freewheel
will have an extremely simple hub, but will have the mechanism inside the larger cogs, visible as
larger spacer rings between the sprockets toward the hub side than on the small cog side.

So basically, the list is much simpler: you've got a worn drivetrain, for which you'll need: chain
(the cause of all the wear. In future, replace sooner. I speak from experience on that score.),
chainrings, cassette, possibly rear derailler if the sprockets in there are worn as well (that's a
*really* badly worn chain if that happened. Again I speak from experience.).

If your shifters are really worn out, then those obviously need to be replaced, but are you sure
they really are and that it's not just gunked up cables or the wear on the various cogs that's
making shifting a *****? A badly worn chain in particular (and again, experience) will make
shifting go badly.

The upgrade to 9 speed additionally requires: 9 sp shifter and a 9 sp cassette, and if you've got a
freewheel rear wheel, a new rear wheel, and if a freehub, a new freehub body.

Jasper

 

[Sheldon Brown]

"Bob from Conshy" wrote:
>
> [worn drivetrain, upgrade 7 to 9 for availability of higher end components]
>
>>Is the following list of parts complete? back wheel, cassette, front and rear deralliers, chain,
>>bottom bracket, crank, and shifters

Jasper Janssen wrote:

> More like overcomplete. The only thing you need to replace on the front are the chainrings,
> assuming your cranks do have replaceable chainrings (and given that they're high end stuff, they
> should).

Actually, I've never found it necessary to replace the chainrings for 9-speed conversion.

> You might also be able to get away with using the same rear derailler.

That's likely true, if it isn't worn out.

> For that matter, the left shifter for the front doesn't need to change either, though it might
> look, feel and operate funny if you have completely different types left and right. You might also
> want to replace the derailler cables, when you're at it. Use high quality compressionless plastic
> lined housings and good quality inner cables.

The cables come with the brifters, so this is not an issue.

> Depending on what particular type of hub you have, you might be able to replace the 7 speed
> cassette body with an 8/9 speed one, thus saving yourself the cost and time of rebuilding the
> wheel. This can almost always be done, if it is a freehub and not a freewheel type. Freehub will
> usually have a bulge in the hub at the right side, that containts the freewheeling mechanism,
> whereas a freewheel will have an extremely simple hub, but will have the mechanism inside the
> larger cogs, visible as larger spacer rings between the sprockets toward the hub side than on the
> small cog side.

That's good advice. See: http://sheldonbrown.com/free-k7.html for help in determining which type of
hub you've got.

The wheel will also require re-dishing, because adding the wider body will move everything to the
left, so the rim won't be centered in the frame anymore.

You may also need to spread the frame. See: http://sheldonbrown.com/frame-spacing.html

> So basically, the list is much simpler: you've got a worn drivetrain, for which you'll need: chain
> (the cause of all the wear. In future, replace sooner. I speak from experience on that score.),
> chainrings, cassette, possibly rear derailler if the sprockets in there are worn as well (that's a
> *really* badly worn chain if that happened. Again I speak from experience.).
>
> If your shifters are really worn out, then those obviously need to be replaced, but are you sure
> they really are and that it's not just gunked up cables or the wear on the various cogs that's
> making shifting a *****? A badly worn chain in particular (and again, experience) will make
> shifting go badly.

More good advice.

Sheldon "Addenda" Brown +--------------------------------------------------------+
| Several excuses are always less convincing than one. | --Aldous Huxley |
+--------------------------------------------------------+ 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

 

[Jack Fortune]

On Wed, 04 Jun 2003 22:32:16 GMT, Sheldon Brown <[email protected]> wrote:
>
> The wheel will also require re-dishing, because adding the wider body will move everything to the
> left, so the rim won't be centered in the frame anymore.
>
> You may also need to spread the frame. See: http://sheldonbrown.com/frame-spacing.html

Sheldon,

I think the original poster had a moutain bike. Would you really want to consider cold setting
the frame for the extra 5mm? (I assume the 7-speed would be 130mm rear spacing and 8/9-speed
would be 135).

Also you might mention the trick (which I learned from you) of using 8 cogs from a 9-speed cassette.
This would only require a new cassette, chain, & shifter for the rear derailer.

best regards,

Jack Fortune Atlanta, Georgia