Shimano 7/8 speed.

Is it possible to use a shimano 8 speed cassette on a shimano (600)
7 speed hub? I'm assuming that the 8 speed spacers are thinner than
the 7 speed ones.

Thanks.


--
anderson

anderson wrote:

Is it possible to use a shimano 8 speed cassette on a shimano (600)
7 speed hub? I'm assuming that the 8 speed spacers are thinner than
the 7 speed ones.

You have to replace the freehub, redish the wheel and respace the frame
to 130mm (shame it's not a mountain bike - the spacing for them changed
with 7 speed).

Given the hassle, you might as well go to 9 speed.

anderson wrote:

Is it possible to use a shimano 8 speed cassette on a shimano (600) 7
speed hub? I'm assuming that the 8 speed spacers are thinner than
the 7 speed ones.

Zog The Undeniable wrote:

You have to replace the freehub,

No, he or she does not need to replace the whole Freehub, just the
Freehub _body_.

See: http://sheldonbrown.com/k7.html#transplant

redish the wheel and respace the frame
to 130mm (shame it's not a mountain bike - the spacing for them changed
with 7 speed).

That's correct.

See also http://sheldonbrown.com/frame-spacing

Sheldon "Ugrades" Brown
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I have an older Trek 730 hybrid that's been slowly evolving into more
of a touring/cross/all-rounder kind of bike. It's got a Shimano Alivio
7 speed setup on it now, and I'd like to go to 8 speed. If the OLD
spacing is already 135mm, would I have to do any spacer swapping on the
hub or re-dishing of the wheel if I swapped out the freehub body? I'm
probably going to spring for new hubs eventually anyway, but I was
thinking about just doing this in the mean time if it isn't too much of
a hassle.

juicemouse wrote:
I have an older Trek 730 hybrid that's been slowly evolving into more
of a touring/cross/all-rounder kind of bike. It's got a Shimano
Alivio
7 speed setup on it now, and I'd like to go to 8 speed. If the OLD
spacing is already 135mm, would I have to do any spacer swapping on
the
hub or re-dishing of the wheel if I swapped out the freehub body?
I'm
probably going to spring for new hubs eventually anyway, but I was
thinking about just doing this in the mean time if it isn't too much
of
a hassle.

Yes, you'll have to play with spacers in order to get everything right.
The 8-speed body is wider than the 7-speed, but I can't recall if that
means there's fewer spacers on the left or more spacers on the right.

You'll definitely have to redish the wheel.

Jeff

"juicemouse" wrote:

I have an older Trek 730 hybrid that's been slowly evolving into
more of a touring/cross/all-rounder kind of bike. It's got a
Shimano Alivio 7 speed setup on it now, and I'd like to go
to 8 speed. If the OLD spacing is already 135mm, would I
have to do any spacer swapping on the hub or re-dishing
of the wheel if I swapped out the freehub body?

Yes, you'll need to re-dish, and you'll lose a spacer from the left end of
the axle. That may mean leaving off the hub's external rubber seal.

I'm probably going to spring for new hubs eventually anyway,
but I was thinking about just doing this in the mean time if it
isn't too much of a hassle.

In that case, consider running eight nine-speed sprockets on your current
wheel, as described here ('8 Of 9 On 7'):

http://www.sheldonbrown.com/k7.html#up7

When you replace your rear wheel, you can go to a full 9-speed system.

James Thomson

Sheldon Brown wrote:

No, he or she does not need to replace the whole Freehub, just the
Freehub _body_.

Excuse my shorthand. If I'd meant the whole freehub I would have said
"hub".

"anderson" wrote in message
...

Is it possible to use a shimano 8 speed cassette on a shimano (600)
7 speed hub? I'm assuming that the 8 speed spacers are thinner than
the 7 speed ones.

The simple way to accomplish your task:

1. Replace the 7 sp. freehub body with a new, 8 sp one
2. Redish a wheel, as it will now shift some 2,5-3 mm to the left
3. Fit an 8 sp casette (I myself would rather go for 9 sp)
4. Fit 8 sp RH Shimano shifter (once again,I myself would rather go for 9
sp)
5. Adjust shifting and enjoy

Cheers,

Tomek Li