Bicycle Mechanics - 8spd freehub with 7spd cluster?

Firstly, I've searched for some few minutes, and have not found this particular info, though I know it has been discussed during my six years' attendance here.

So, to the purpose:

--I've come into possession of a nice doublewall 8spd rear wheel.
--I want to run it on my 7spd rig.
--All is 130mm old/spacing, and same diameter.
--I don't want to redish (but will, if no other way presents)
--Tools and parts are not an issue.

Is it feasable to place a spacer behind my large cog? Or some other method?

Perhaps some of you wheel-building folk who discussed altering (removing) rear-wheel dish some weeks ago have advice? That was interesting, btw.

According to Sheldon (http://www.sheldonbrown.com/k7.html), all you need to do is add a 4.5 mm spacer.

Ugh. I looked there, and did not see (perhaps I shall look "more slowly" in future). UA, you guide me, and immediately I find:

"Also, hubs marked "8-speed, 9-speed or 10-speed will work with any number of sprockets! (Add a 4.5 mm spacer before installing a 7-speed cassette on an 8-, 9-, or 10-speed hub.)"

Thank you, Sir.

No problem, any time I can pass along the wisdom of someone else, I'll do it! :D

Actually there's a bit more to it than that.

If you examine your cassette carefully you may find that it's held together with some small bolts or rivets that project out on the back side. The typical 4.5mm spacer will interfere with those. Remove the little bolts or grind off the rivet heads and, if necessary, install the cassette one cog at a time.

Actually, Retro Grouch, I have already done that. I've a "modified" corncob upper 5 cogs:

12-14-15-16-18, then a 21 & 24. I lost the 28 and Dremel'd a 15 to align the ramps. The 15 is from a "M" cassette; the others from an "E."
If I get unlazy and decide to build an 8spd rig (I've a '93 Rockhopper lump waiting, but my current rig runs without problem), I'll add an 11, or perhaps a 13.

A question:

--Are the 7spd spacers the requisite 4.5mm I need? Or from something else? The Late Sheldon's site doesn't appear at second glance to specify.

Again, I thank each, and all.

Spacer thickness- IOW no. My LBS sells the 4.5MM spacer for $2!
http://sheldonbrown.com/k7.html#spacing

I've taken an "E" & an "H" to make a semi corn cob.
13-14-15-16-18-21-24

Then I found an 8 speed FH body off a junk wheel and made eight 7 speed cogs fit by thinning the spacers- (don't use power tools) :o
13-14-15-16-17-19-21-24. Love it!

Bill, I'll run a 13 today, just for kicks. Thanks for the lead to Sheldon's spacing cataloge; I must be "spacing," having missed it! I will, also, cheap-out and thin a spacer and use that with a cog to effect the need; my LBS of choice will not be along my direction of ride on this post-Solstice day.

I'm concluded that I still run 7spd because I really have always preferred
the push/push Rapidfires (regarding flatbars).

BTW, ? IOW?

Actually, Retro Grouch, I have already done that. I've a "modified" corncob upper 5 cogs:

12-14-15-16-18, then a 21 & 24. I lost the 28 and Dremel'd a 15 to align the ramps. The 15 is from a "M" cassette; the others from an "E."
If I get unlazy and decide to build an 8spd rig (I've a '93 Rockhopper lump waiting, but my current rig runs without problem), I'll add an 11, or perhaps a 13.

A question:

--Are the 7spd spacers the requisite 4.5mm I need? Or from something else?

Since you're already to the cassette mixing stage you probably have a drawer full of cassette spacers. The ones that go between the cogs are too narrow but I suspect that if you add one or two of the star shaped ones it'll work. The spacing between the cogs that affects the indexing is already established. All you really need to do is to fill up the space on the wider free hub body so the lock ring will keep the cassette from shifting laterally.

Actually, if it was my bike, I think that I'd transplant the narrower 7-speed freehub body onto the new wheel. You'll have to redish the wheel, of course, but that'll make it stronger.

Since you're already to the cassette mixing stage you probably have a drawer full of cassette spacers. The ones that go between the cogs are too narrow but I suspect that if you add one or two of the star shaped ones it'll work. The spacing between the cogs that affects the indexing is already established. All you really need to do is to fill up the space on the wider free hub body so the lock ring will keep the cassette from shifting laterally.

Actually, if it was my bike, I think that I'd transplant the narrower 7-speed freehub body onto the new wheel. You'll have to redish the wheel, of course, but that'll make it stronger.

Yes, I'm a junkie.

I've several 7spd cassettes, but I'm not aware of the "star shaped" item to which you refer, unless you mean the thin metal spacer found under the smallest cog of some cassettes. Would you clarify?

Speaking of the redish, I am going to relace this rim's companion to an exage, or a parralax rear hub. That is, when the serious rain begins.