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Q: 7spd - > 9spd cassette/hub issue(4 posts)

Q: 7spd - > 9spd cassette/hub issuecrank monkey
Jul 11, 2001 11:26 PM
Can I replace my 7 speed RSX cassette w/a 9 speed DA/Ultegra cassette, on the existing hub, or do I need to replace/upgrade the hub as well?

I'd guess that the narrow 9spd cassette fits in the same 130mm space, but was wondering what a real wrencher has to say.

Thanks
re: Q: 7spd - > 9spd cassette/hub issueD_Alex
Jul 12, 2001 6:24 AM
Are you SURE that it is a 130mm soacing? Most 7-speeds I've seen are 126mm. In any event, no, it won't work. 9 speed hubs are more deeply dished, and their freehubs are longer. Also, D/A freehubs use a different splining pattern than other shimano components do. Your drailleur would need to be replaced, too, since a 7 speed derailleur probably would not have the reach needed. The chain would also need to be replaced. And even if it does fit, why would you bother? You will have a light, fragile, expensive, fast wearing cogset mounted on a cheap, heavy, slow hub. It doesn't make sense, any way you look at it.
Here's what you have to do:Spoke Wrench
Jul 12, 2001 7:20 AM
1. Buy a new 8/9 speed freehub body and an 8/9 speed axle set. It's possible to get by without the axle set, but you may need to find some axle spacers that are the right width.
2. Take the axle out of your old hub. Don't remove the right side cone and lock nut so you can match the amount of axle exposure later.
3. Use a 10mm allen wrench to remove the 7sp freehub body.
4. Put on the new 8/9 speed freehub body.
5. Install the new axle set.
6. Redish the wheel by tightning the right side spokes and loosening the left side spokes. Be sure you retain adequate tension on the left side or you will suffer repeated broken spokes.

Personally, I think that's too much work to do on a RSX hub. You also probably have non-eyeletted rims. Those are going to be hard to tension enough to get adequate tension on the non-drive side spokes.
Why bother?D_Alex
Jul 12, 2001 8:34 AM
You can'tmake a silk purse out of a sow's ear, and you can't make an RSX hub into a D/A hub, either. There IS a reason why the D/A hubs are about $100 more. Maybe you should just look for some nice, NOS Ultegra cogs?