HardyWeinberg

Performance sale got me looking at wheels; they have a nice set of mtn bike wheels w/ 9 spd XT hub. Can I use my 8 spd cassette on that?

https://www.performancebike.com/shop/...TOKEN=78327654

Then I was looking at these wheels, and realized they didn't say anything about what size cassette the hub is for:

https://www.performancebike.com/shop/...tegory_ID=5310

but I assume that will work for 8 spd, does that seem reasonable?

Thanks in advance...

(I am considering new wheels 'cause my existing wheels have aluminum nipples that are pitting; could the spokes possibly be aluminum too? they look about as scaly as the nipples)

moxfyre

8-speed and 9-speed Shimano cassettes are the same width and have the same spline pattern. You can use an 8-speed cassette with a 9-speed hub... those same hubs are often called "8/9-speed" hubs

well biked

Yes, the wheels are compatible with your 8-speed cassette. No, the spokes on your old wheels aren't aluminum, they're steel-

HardyWeinberg

Thanks!

I didn't think the spokes could be aluminum.

moxfyre

Aluminum threads aren't strong enough for spokes. Nearly all good spokes are stainless steel. Some unnecessarily expensive ones are titanium, which is slightly lighter, and there have been carbon fiber spokes made, though I'm told they are prone to sudden catastrophic failure.

tonyt

You may need a splined spacer/shim to fit behind the cassette. The thickness will depend on the hub/cassette combination.

Your LBS should have these and they are cheap, bring the wheel and cassette with you so you get the correct thickness, the thicker ones are aluminum and the thinner ones steel.

moxfyre

No, you won't need a spacer for an 8-speed cassette on a 9-speed hub. 8-speed and 9-speed Shimano-compatible cassettes have the same thickness: https://sheldonbrown.com/k7

cyccommute 

Probably mild steel or zinc plated if they are scaled and corroded. Or have you been riding on salted roads?

HardyWeinberg

I got the bike this past January (it's a 1999 model near as I can tell). It came from a dumpster in Boston, so it had some salty winters in its past.

Could the spoke nipples be zinc-plated too? What would the Zn be plated onto, if that were the case?

moxfyre

Good quality spoke nipples are NICKEL-plated brass, making them look silvery. What do you mean, the nipples are pitting? If there's no rust on the spokes, and you're not breaking them, I wouldn't worry about it.

well biked

The spokes are steel, they might be galvanized steel, which you will see on lower end wheels sometimes, particularly older ones. Galvanizing is a process that coats steel in a protective zinc coating. Think of a chain link fencepost, those are usually galvanized steel. One that's brand new looks shiny and nice, but after being out in the weather for years, they'll take on a dull, grey look. I've got an old wheelset that has galvanized spokes, and they look terrible, very oxidized and maybe a little pitted on the surface if you were to look closely at them. That's probably what you're seeing with yours, especially since you say the bike has probably been ridden in salt. As moxfyre says, if the spokes aren't rusted, there's probably nothing functionally wrong with them. Better wheels will have stainless steel spokes-

DieselDan

You only need a spacer on an 8/9 hub with a 7 speed cassette (4mm) and 10 speed cassette (1mm).

tonyt

Shimano M950 XTR hub, Shimano M737 11-30 8-speed cassette: You NEED A SPACER I KNOW FROM EXPERIENCE!!! Without a thin (steel) spacer lock ring would not tighten down on cassette, thick (aluminum) spacer would only engage the threads ca. 1 1/2 turns. Why do you think LBS stocks these spacers?

Maybe not all SHIMano 8/9 speed combos need a spacer but some do.

'nother

Interesting.

Normally they stock the spacers for putting 10s cassettes onto 8/9s hubs (that *definitely* requires a spacer). Maybe the M950 hub is an anomaly. If you need a spacer for 8s on that hub, you'd need one for 9s as well, 'cause as has been stated, the cassettes are the same (overall) width.

well biked

+1..........They're cramming more gears into the same amount of space. The Shimano 8/9speed freehub is completely compatible with either eight or nine speed cassettes, no spacers needed, the cassettes are the same width on the hub-

tonyt

O.K. after some researching the issue is using a cassette with an 11 tooth smallest cog on SOME SHIMano 8/9 freehubs

Some of the SHIMano freehubs are fully splined the whole height of the freehub (i.e. M950 XTR), others are splined slightly shorter, the freehub is in fact the same height for both only the splines are different. The former of these two will only work with cassettes having 12 tooth or larger small sprocket; unless you shim it.

On shimano cassettes with 11 tooth small cogs the corresponding cutout to accept the freehub spline is not as deep as on larger (>12) small cogs, thus the cassette will not drop all the way down on the freehub and a spacer is needed.

On my M950 XTR hub this was the case and I needed a shim to get the cassette to fit. I also had to space the hub just a bit to the non-drive side on the axle using a washer to get the small cog to clear the chain stay. This was caused by the shimming the cassette which thus effected the chainline.

Looking on Sheldons site he in fact does explain this and suggests another solution, taking a grinder to the freehub and putting a bevel on the splines so the 11 tooth small cog will fully seat on the freehub. I guess you'd need to be a little careful that you did not remove too much material and not have enough spline left to get proper engagement of the small (11 tooth) sprocket.

1) I hope this clears up the SHIMano 8/9 speed freewheel/hub compatibility question (e.g. are you using an 11 tooth small cog and is your freehub fully splined)

2) This also explains why there are two common spacer thicknesses for SHIMano freehubs, the thick one to make 7 speed cassettes work on 8/9 speed hubs and the thin one to make some cassettes (11 tooth small cog) fit on some 8/9 speed hubs (fully splined).

P.S. I guess this is why early XTR cassettes had gearings like 12-32

HardyWeinberg

So I read in one of the 'Zinn and the Art of...' books that the 11t cog on 8 spd cassette/9spd hub 'issue' was only an issue on certain cassette/hub combinations where one (or both?) of the parts was made in the early 1990s. Sure enough, the 8 spd 11-30 cassette fit perfectly on the 9 spd hub, no spacers needed.

moxfyre

Right, early cassette hubs had the splines extending all the way to the end of the freehub body, which prevented an 11T cog from being installed. Shimano later did away with this for later 8,9,10 speed hubs. I believe the newer version is called "Hyperglide-C" where C stands for "compact." See www.sheldonbrown.com/k7 for the details.

Al1943

Good quality nipples are also aluminum alloy. That's all I use.

Al

moxfyre

Sure, but Al nipples are more expensive and can have corrosion problems. Of course, they are lighter than brass nipples for those who care about such things

well biked

Their main disadvantage, from what I've heard, is that the shoulders of the nipples will "round over" much easier than brass nipples, eventually making it impossible to turn the nipples with a spoke wrench. I've actually had no problems with this, and I've had more than one wheelset with aluminum nipples. But I've heard it's a problem from a couple of people who work with wheels a lot more than I do........A drop of oil at each nipple/spoke junction about once a year will keep corrosion from being a problem; it's a good idea for brass or aluminum nipples, makes truing much easier-