Shimano Hub 7 to 9 speed - Can i just change the freehub?



R

Reader

Guest
Hi,

Is it possible to upgrade from a 7speed cassette to a 9speed
just by changing the freehub? Or do i need to get a
completely new hub?

Regards,

Reader
 
Reader wrote:

> Is it possible to upgrade from a 7speed cassette to a
> 9speed just by changing the freehub? Or do i need to get a
> completely new hub?

And the rear mech. And the rear shifter. Apart from that,
no problem.

8 speed might be easier, most 7 speed mechs will
handle 8 speed.

--
Guy
===
May contain traces of irony. Contents liable to settle after
posting. http://www.chapmancentral.co.uk

Victory is ours! Down with Eric the Half A Brain!
 
"Just zis Guy, you know?" <[email protected]> wrote in message
news:[email protected]...
> Reader wrote:
>
> > Is it possible to upgrade from a 7speed cassette to a
> > 9speed just by changing the freehub? Or do i need to get
> > a completely new hub?
>
> And the rear mech. And the rear shifter. Apart from that,
> no problem.
>
> 8 speed might be easier, most 7 speed mechs will handle
> 8 speed.
>

...and don't forget that the cones will be different, as
will axle spacing. You'll also therefore need to redish the
wheel. The chain and cassette will obviously both have to
go, but I'm sure you'd anticipated this.

---
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"Just Zis Guy" writes:
> And the rear mech.

That is absolutely unnecessary.

> And the rear shifter. Apart from that, no problem.

The chain would also need to be replaced with a nine speed model. The right-hand cone and seal must match the freehub body. As the new freehub body adds a few millimetres to the right hand side of the hub, it is usually necessary to re-dish the wheel slightly, re-space the axle, and sometimes to spread the frame.

> 8 speed might be easier, most 7 speed mechs will handle
> 8 speed.

Any derailleur that will handle eight speeds will also handle nine, an eight speed cassette having the same overall width as a nine.

One is not obliged to answer a question to which one does not know the answer.

N. Lenderby (Mrs)
 
Reader wrote:
> Hi,
>
> Is it possible to upgrade from a 7speed cassette to a
> 9speed just by changing the freehub? Or do i need to get a
> completely new hub?
>
> Regards,
>
> Reader

Like one of the other replies implied 9 speed is wider than
7 so you will probably have to respace the frame and redish
the wheel. A good compromise in my opinion is to use 8
sprockets and 7 spacers from a 9 speed cassette, these will
fit onto a 7 speed hyperglide cassette body and will not be
anywider than it was before so you don't need to respace the
frame and redish the wheel. You'll still need 9 speed
shifters and chain and may need a new rear mech. This is
pretty much what I am going to do later this week, actually
my bike will be ugraded from 6 to 8 this way. It offers a
good upgrade path IMO, when I decide to get a new rear
wheel, I will then respace the frame and fit the ninth
sprocket to get 9 speed. Sheldon Brown calls this 8 of 9 on
7, look it up.
 
Just zis Guy, you know? wrote:
> Reader wrote:
>
>
>>Is it possible to upgrade from a 7speed cassette to a
>>9speed just by changing the freehub? Or do i need to get a
>>completely new hub?
>
>
> And the rear mech. And the rear shifter. Apart from that,
> no problem.

Not forgetting to have the frame re-spaced from 126mm to
130mm ! (not possible with aluminium frames, sadly,
otherwise I might try a 9 or 10-speed setup one day ...).

** Phil.
 
In article <[email protected]>, Simon D wrote:
>"Just zis Guy, you know?" <[email protected]>
>wrote in message news:[email protected]
>berlin.de...
>> Reader wrote:
>>
>> > Is it possible to upgrade from a 7speed cassette to a
>> > 9speed just by changing the freehub? Or do i need to
>> > get a completely new hub?
>>
>> And the rear mech. And the rear shifter. Apart from that,
>> no problem. 8 speed might be easier, most 7 speed mechs
>> will handle 8 speed.
>
>...and don't forget that the cones will be different, as
>will axle spacing. You'll also therefore need to redish the
>wheel. The chain and cassette will obviously both have to
>go, but I'm sure you'd anticipated this.

Or, from what I remember Sheldon saying, you can use 8
sprockets of a 9-speed system on a 7-speed hub, without
redishing the wheel or spreading the frame (but it will need
a new shifter and chain as much as a full move to 9 would).
 
Philip TAYLOR [PC87S/O-XP] wrote:

>>> Is it possible to upgrade from a 7speed cassette to a
>>> 9speed just by changing the freehub? Or do i need to get
>>> a completely new hub?

>> And the rear mech. And the rear shifter. Apart from that,
>> no problem.

> Not forgetting to have the frame re-spaced from 126mm to
> 130mm ! (not possible with aluminium frames, sadly,
> otherwise I might try a 9 or 10-speed setup one day ...).

Unless your frame is already 130 OLN or more, as every cassette-
based system I have seen has been (indeed none of our bikes
is currently less than this, although at least three were
supplied with 7sp freehubs). I freely admit to limited
experience, though.

I reckon 8sp will just work, 9sp might be harder. But what
do I know?

--
Guy
===
May contain traces of irony. Contents liable to settle after
posting. http://www.chapmancentral.co.uk

Victory is ours! Down with Eric the Half A Brain!
 
Just zis Guy, you know? wrote:

>> Not forgetting to have the frame re-spaced from 126mm to
>> 130mm ! (not possible with aluminium frames, sadly,
>> otherwise I might try a 9 or 10-speed setup one day ...).
>
> Unless your frame is already 130 OLN or more, as every cassette-
> based system I have seen has been (indeed none of our
> bikes is currently less than this, although at least three
> were supplied with 7sp freehubs). I freely admit to
> limited experience, though.

Maybe your 7sp experience is limited to "MTB"-style
hubs.......

From http://www.sheldonbrown.com/frame-spacing.html : 120 mm
Rear 5-speed, Ultra 6, newer track hubs. 126 mm Rear 6- and
7-speed (road). 130 mm Rear 7-speed (MTB) and 8- 9- and 10-
speed (road). 135 mm Rear 7- 8- and 9-speed (MTB)

"8 Of 9 On 7" : http://www.sheldonbrown.com/k7.html#up7

~PB
 
"Philip TAYLOR [PC87S/O-XP]" <[email protected]> wrote in message
news:[email protected]...
> Just zis Guy, you know? wrote:
> > Reader wrote:
> >
> >
> >>Is it possible to upgrade from a 7speed cassette to a
> >>9speed just by changing the freehub? Or do i need to get
> >>a completely new hub?
> >
> >
> > And the rear mech. And the rear shifter. Apart from
> > that, no problem.
>
> Not forgetting to have the frame re-spaced from 126mm to
> 130mm ! (not possible with aluminium frames, sadly,
> otherwise I might try a 9 or 10-speed setup one day ...).
>
And having re-spaced the frame, you'll have to adjust the
size of the space you use to park your bike in your garage,
and if there isn't room you'll just have to move house.

Apart from that, no problem :-^
 
In article <[email protected]>, Nora Lenderby wrote:
>"Just Zis Guy" writes:
>> And the rear mech.
>
>That is absolutely unnecessary.
[...]
>> 8 speed might be easier, most 7 speed mechs will handle
>> 8 speed.
>
>Any derailleur that will handle eight speeds will also
>handle nine, an eight speed cassette having the same
>overall width as a nine.

Will all derailleurs designed for seven speeds handle eight,
even ones from before eight speed systems existed? If not,
it _might_ be necessary to change it.

(http://www.sheldonbrown.com/k7.html#up7 does say "Your old
7-speed derailer should work OK if it isn't too badly worn",
but only in the context of using 8 of 9 sprockets to keep
the same overall width as a 7.)
 
Alan Braggins wrote:
> In article <[email protected]>,
> Nora Lenderby wrote:
>> "Just Zis Guy" writes:
>>> And the rear mech.
>>
>> That is absolutely unnecessary.
> [...]
>>> 8 speed might be easier, most 7 speed mechs will handle
>>> 8 speed.
>>
>> Any derailleur that will handle eight speeds will also
>> handle nine, an eight speed cassette having the same
>> overall width as a nine.
>
> Will all derailleurs designed for seven speeds handle
> eight, even ones from before eight speed systems existed?
> If not, it _might_ be necessary to change it.
>
> (http://www.sheldonbrown.com/k7.html#up7 does say "Your
> old 7-speed derailer should work OK if it isn't too badly
> worn", but only in the context of using 8 of 9 sprockets
> to keep the same overall width as a
> 7.)

The only restraining factor would be the overall distance
that the mech can move. Sheldon lists the spacings and
sprocket thicknesses for 7, 8 and 9 speed cassettes so it
should be possible to work it out. In my opinion it'll be
worth a try if you already have a 7 speed mech.
 
Reader wrote:

> Hi,
>
> Is it possible to upgrade from a 7speed cassette to a
> 9speed just by changing the freehub? Or do i need to get a
> completely new hub?

You might need a longer axle' you'll definitely need
more spacers.
 
Nora Lenderby <[email protected]> wrote in message news:<[email protected]>...
> "Just Zis Guy" writes:
> > And the rear mech.
>
> That is absolutely unnecessary.
>
> > And the rear shifter. Apart from that, no problem.
>
> The chain would also need to be replaced with a nine speed
> model. The right-hand cone and seal must match the freehub
> body. As the new freehub body adds a few millimetres to
> the right hand side of the hub, it is usually necessary to
> re-dish the wheel slightly, re-space the axle, and
> sometimes to spread the frame.
>
> > 8 speed might be easier, most 7 speed mechs will handle
> > 8 speed.
>
> Any derailleur that will handle eight speeds will also
> handle nine, an eight speed cassette having the same
> overall width as a nine.
>
> One is not obliged to answer a question to which one does
> not know the answer.
>
> N. Lenderby (Mrs)
>
>
>
> --

I knew the chain and cassette would need updating. I have a
mtb and the rear frame spacing is 135mm so that should be
ok. I brought a 9sp rear mech a while ago as mine broke and
a 9sp is usable on 8 and 7sp. I didn't realise I would need
to re-dish the wheel though. Is this easy to do myself?

So I need to re-dish the wheel and change the freehub and
spindle. I already have a 9sp chain and cassette. The
shifters are the next purchase...

Thanks all. Reader
 
Reader wrote:

>
>
> I knew the chain and cassette would need updating. I have
> a mtb and the rear frame spacing is 135mm so that should
> be ok. I brought a 9sp rear mech a while ago as mine
> broke and a 9sp is usable on 8 and 7sp. I didn't realise
> I would need to re-dish the wheel though. Is this easy to
> do myself?
>
> So I need to re-dish the wheel and change the freehub and
> spindle. I already have a 9sp chain and cassette. The
> shifters are the next purchase...
>
>
> Thanks all. Reader
You only need to redish the wheel if you are making the
whole axle assembly wider. If your wheel will fit in the
frame once you have fitted the new cassette without forcing
the frame apart you do not need to redish the wheel.

Redishing involves loosening and tightening spokes so that
the rim moves sideways so that it again ends up in the
centre of the axle. Easy to do ? I have not done it, looks
easy but I would say its also easy to completely bogart the
wheel by attempting this.

Read Sheldon Browns site.
 
Just zis Guy, you know? wrote:

> Reader wrote:
>
>
>>Is it possible to upgrade from a 7speed cassette to a
>>9speed just by changing the freehub? Or do i need to get a
>>completely new hub?
>
>
> And the rear mech. And the rear shifter. Apart from that,
> no problem.
>
> 8 speed might be easier, most 7 speed mechs will handle
> 8 speed.
>

Although an 8 Speed hub will also take a 9 speed cassette.

Cheers

Michael
 
MSeries wrote:

> Reader wrote:

> Redishing involves loosening and tightening spokes so that
> the rim moves sideways so that it again ends up in the
> centre of the axle. Easy to do ? I have not done it, looks
> easy but I would say its also easy to completely bogart
> the wheel by attempting this.
>

If you can true a wheel you should be able to re dish it as
the process is very similar, and even easier if you have a
truing stand and dishing tool.

Cheers

Michael
 

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