Can I fit a 7-speed cassette on a 9-speed hub?

[swee'pea99]

Just fitted a 7-speed cassette on a 9-speed hubbed wheel I bought from a fellow cc-er, and it wobbles, with 2-3mm play. Have I made a blunder? I really don't want a 9-speed setup...I'd assumed 9-speed meant 'anything up to 9' - does it actually mean 9, period? Or can I take up the slack using spacers? Or what?

 

[Hacienda71]

You can get spacers for a 9 speed hub to run an 8 speed cassette i have but i don't know about a 7 on a 9. However i don't see any reason why if you have the right size spacer. You might want to ask your LBS if such sizes spacers are available. You will have to fettle the max travel on your rear mech.

 

[swee'pea99]

Thanks Hacienda - would this do? (Don't understand the ref to cut-outs....?)

 

[TheDoctor]

That's the beasty. However - the cut-outs are to clear the rivet heads on the back of the cassette, the ones that hold the cassette and spacers together. As such, you do really want the cut-outs. I'd get this one from Wiggle. It's cheaper too!!!

BTW, a 8 speed hub is a 9 speed hub is a 10 speed hub - they're identical.

 

[Hacienda71]

That is similar to the spacer i used. To be honest three quid seems a little pricey. I would be tempted to pop in to your LBS, mine didn't charge me although i would suspect i was lucky. You will then have recourse if it isn't the right size, it is just an aluminum ring that slides over the body of the hub so the cassette is a little further out, should cost pennies. I am not sure what the reference to "pre cutouts" is either. Good luck

 

[swee'pea99]

Thanks Hacienda and Doc - just ordered the wriggle one. LBS is a bit of a pain tbh, and £3 I can definitely live with for the convenience.

 

[TheDoctor]

Look on the back of a cassette, and you'll see three bolt heads or rivet heads. The cut outs in the spacer sit over these. That way, when you do up the lockring, the compression is spread across the whole cassette, rather than the three boltheads.

 

[longers]

Without looking at the back of a cassette to check - could you just file a plain spacer in the appropriate places?

 

[TheDoctor]

Yes, you could.

 

[Crankarm]

That's the beasty. However - the cut-outs are to clear the rivet heads on the back of the cassette, the ones that hold the cassette and spacers together. As such, you do really want the cut-outs. I'd get this one from Wiggle. It's cheaper too!!!

BTW, a 8 speed hub is a 9 speed hub is a 10 speed hub - they're identical.

Er ..... no. 10 speed hubs have different spacings on the freewheel to 8 spd so one cannot interchange 8 and 10 speed. A bit like trying to use a similar but different front door key. It won't fit.

 

[TheDoctor]

My back wheel says you're wrong. Early DuraAce 10 speed had an alloy freehub that was 10 speed only. Everything else is 8/9/10 speed.

Source - Sheldon.

 

[andy_wrx]

Agreed.
Sheldon clearer here http://www.sheldonbrown.com/dura-ace.html#10

There are certain Shimano wheels/hubs which are 10sp-only : 7800 DA and 6600 Ultegra from a few years ago, when they made them with an alu freehub body - they are the same spline arrangement, but the splines are deeper (as alu is softer) and so a 7/8/9sp cassette won't slide onto them (nor a SRAM 10sp cassette either, it has usual spline grooves).
Some other manufacturers have made these as well and they are normally called '10sp-only'.

However most hubs that will take 10sp will also take 8sp & 9sp (lower-spec Shimano with steel freehub, DA or Ultegra with steel or ti freehub, most other manufacturers too : SRAM are this fitting)
- these are usually called '8/9/10sp wheels'

Any hub that will take 8sp or 9sp will take 10sp (needs a thin cassette spacer as 10sp is narrower than 8sp & 9sp - the deeper spline grooves in a 105/Ultegra/DA Shimano 10sp cassette fit the shallower splines on the freehub no problem).

And they'll take 7sp too, with the thicker spacer detailed at the top of the thread.