Upgrading 7 speed to 9 speed.



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Sam Yorko

Guest
Well, I think I'm going to bite the bullet and replace the shift mechanism on my bike. It's a 1992
Trek 930 Singletrack, and it came with 7 speed rear. I guess I can get 7 speed shifters, but I'm
wondering if I can go with an 8 or 9 speed hub. I went to Sheldon's web site, but I couldn't find
anything obvious in the list of articles. For instance, what distance do I need between the dropouts
to be able to take 9 speeds? The current hub has a rather large spacer on the side away from the
freewheel, so I'm wondering if it's already wide enough....

Sam
 
S

Sheldon Brown

Guest
Sam Yorko wrote:
> Well, I think I'm going to bite the bullet and replace the shift mechanism on my bike. It's a 1992
> Trek 930 Singletrack, and it came with 7 speed rear. I guess I can get 7 speed shifters, but I'm
> wondering if I can go with an 8 or 9 speed hub. I went to Sheldon's web site, but I couldn't find
> anything obvious in the list of articles.

Actually, the list of articles is not the best entry point for my site. It's generally best to start
at the Bicycle Glossary, which also has links to all of the articles.

The information you seek is under the "Spacing" entry, see:

http://sheldonbrown.com/gloss_sp-ss.html#spacing

> For instance, what distance do I need between the dropouts to be able to take 9 speeds? The
> current hub has a rather large spacer on the side away from the freewheel, so I'm wondering if
> it's already wide enough....

Yes, pretty much any bike from the '90s or later will handle an 8-/9-speed hub.

Sheldon "http://sheldonbrown.com/glossary" Brown
+---------------------------------------------------+
| Time shouldn't just pass; things should happen. | --Harry Turtledove |
+---------------------------------------------------+ 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
 
W

...Who Cares

Guest
Why don't ya just buy a new bike?

To your exact specs. Just imagine the joy you would have riding it instead of your other
piece of junk.

You can afford it.

Go on -DO IT

"Sheldon Brown" <[email protected]> wrote in message news:[email protected]...
> Sam Yorko wrote:
> > Well, I think I'm going to bite the bullet and replace the shift mechanism on my bike. It's a
> > 1992 Trek 930 Singletrack, and it came with 7 speed rear. I guess I can get 7 speed shifters,
> > but I'm wondering if I can go with an 8 or 9 speed hub. I went to Sheldon's web site, but I
> > couldn't find anything obvious in the list of articles.
>
> Actually, the list of articles is not the best entry point for my site. It's generally best to
> start at the Bicycle Glossary, which also has links to all of the articles.
>
> The information you seek is under the "Spacing" entry, see:
>
> http://sheldonbrown.com/gloss_sp-ss.html#spacing
>
> > For instance, what distance do I need between the dropouts to be able to take 9 speeds? The
> > current hub has a rather large spacer on the side away from the freewheel, so I'm wondering if
> > it's already wide enough....
>
> Yes, pretty much any bike from the '90s or later will handle an 8-/9-speed hub.
>
> Sheldon "http://sheldonbrown.com/glossary" Brown
> +---------------------------------------------------+
> | Time shouldn't just pass; things should happen. | --Harry Turtledove |
> +---------------------------------------------------+ 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
 
B

B. Sanders

Guest
"...who cares" <[email protected]> wrote in message
news:[email protected]...
> Why don't ya just buy a new bike?

I might agree on this point, depending on several factors. Mainly, if he wants to ride off-road
most of the time, a suspension fork is essential gear; and I believe that the '92 Trek 930 was
rigid. Also, it's just about impossible to find 1" threaded forks and quill stems these days.
Purely for the sake of coming up to the current standard, it would be fairly easy to make a case
for a new bike.

OTOH: If it's in good shape, it fits him, and he likes it, he should fix it up and ride it for
another 11 years.

> To your exact specs. Just imagine the joy you would have riding it
instead
> of your other piece of junk.

Junk? The Trek 930 frame is nicely made from True Temper butted CrMo tubing. Not junk at all.
Components are mid-range quality, actually pretty nice.

> You can afford it.

Yes, perhaps he can. Bikes do wear out. Replacing tires, shifters, drivetrain, rims, etc. could
easily run $250+ from a local bike shop. A current-model bike comparable to the Trek 930 can be had
for $500-ish these days.

-Barry
 
P

Paul Kopit

Guest
On Sat, 05 Apr 2003 21:57:51 -0800, Sam Yorko <[email protected]> wrote:

>Well, I think I'm going to bite the bullet and replace the shift mechanism on my bike. It's a 1992
>Trek 930 Singletrack, and it came with 7 speed rear. I guess I can get 7 speed shifters, but I'm
>wondering if I can go with an 8 or 9 speed hub. I went to Sheldon's web site, but I couldn't find
>anything obvious in the list of articles. For instance, what distance do I need between the
>dropouts to be able to take 9 speeds? The current hub has a rather large spacer on the side away
>from the freewheel, so I'm wondering if it's already wide enough....

If your hub is Shimano, and a 135 mm MTB spaced, you can get use a 9sp cassette and put 8 of 9 cogs
on it. You don't have to do anything with the rear wheel spacing. If you want 9 cogs, you need to
remove the 7 sp hub body and replace with the 4.5 mm wider 8/9 sp hub body. You'll need to move the
axel locknut on the drive side about 2.5 mm closer to the dropout and tighten the drive side spokes
until the wheel is centered between the chainstays or brake arch. Put the same spacers back. You'll
need new shifters too.
 
A

A Muzi

Guest
"Sam Yorko" <[email protected]> wrote in message news:[email protected]...
> Well, I think I'm going to bite the bullet and replace the shift mechanism on my bike. It's a 1992
> Trek 930 Singletrack, and it came with 7 speed rear. I guess I can get 7 speed shifters, but I'm
> wondering if I can go with an 8 or 9 speed hub. I went to Sheldon's web site, but I couldn't find
> anything obvious in the list of articles. For instance, what distance do I need between the
> dropouts to be able to take 9 speeds? The current hub has a rather large spacer on the side away
> from the freewheel, so I'm wondering if it's already wide enough....

For a nine, you'll need a set of shifters, a new cassette, chain and a hub suitable to nine cogs.
The frame spacing, rear changer, crank, front changer are all OK if you switch. And do go either
seven or nine as eight has a clouded future.

--
Andrew Muzi http://www.yellowjersey.org Open every day since 1 April 1971
 
S

Sam Yorko

Guest
"B. Sanders" wrote:
>
> "...who cares" <[email protected]> wrote in message
> news:[email protected]...
> > Why don't ya just buy a new bike?
>
> I might agree on this point, depending on several factors. Mainly, if he wants to ride off-road
> most of the time, a suspension fork is essential gear; and I believe that the '92 Trek 930 was
> rigid. Also, it's just about impossible to find 1" threaded forks and quill stems these days.
> Purely for the sake of coming up to the current standard, it would be fairly easy to make a case
> for a new bike.
>
> OTOH: If it's in good shape, it fits him, and he likes it, he should fix it up and ride it for
> another 11 years.
>
> > To your exact specs. Just imagine the joy you would have riding it
> instead
> > of your other piece of junk.
>
> Junk? The Trek 930 frame is nicely made from True Temper butted CrMo tubing. Not junk at all.
> Components are mid-range quality, actually pretty nice.
>
> > You can afford it.
>
> Yes, perhaps he can. Bikes do wear out. Replacing tires, shifters, drivetrain, rims, etc. could
> easily run $250+ from a local bike shop. A current-model bike comparable to the Trek 930 can be
> had for $500-ish these days.
>
> -Barry

I am the OP, and I've never really ridden the bike as a mountain bike (a bit of dirt, but nothing
radical). When I got it, I wanted something a little more sturdy and comfortable than a street bike
to commute with, and hybrids really were not an option yet. It seems to me that that vintage Trek
really could be considered to fit the modern definition of hybrid. And I've put on a lot of miles
onto that bike.... Besides, I really can't afford new right now.

Sam
 
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