Depending on your bike frame you may have to actually get a new frame. The rear triangle on your current bike may not be wide enough to fit a 9 speed wheel back there. Check it out first.

If your old frame was built to accept a 7 speed rear hub, the space between the rear dropouts will be 5mm too narrow to accept a 9 speed hub, although you could probably force it in by pulling the chainstays apart a little. This might marginally affect the rear derailleur alignment though. Is there any reason why you want to just upgrade the bike rather than selling the old one and buying a new 9 speed one? There are some great deals to be had on new bikes and it's probably almost as cheap to sell the old one and buy a new 9 speed bike as to upgrade the old one, when you consider you're going to need a new hub with rear wheel re-build, cassette, rear and front derailleurs, STI shifters, new chainrings, new chain and new cables and all the work required to change things.

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Put the bunny back in the box.

Buy a new bike dude.

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Tom Demerly
The Tri Shop.com

I say definately do it if you have a high quality lugged steel frame. The ride quality and asthetics of some of those frames are still way superior to the newer aluminium frames of today. If you're thinking of upgrading 7 sp aluminium I wouldn't bother.

The older 7 sp had a 126mm rear spacing compared to the 130mm of today. That's only 4mm. With a steel fame you can quite often spring them enough to fit a 130mm wheel/cassette combo. If you actually want to spread the rear triangle it's not that hard. Sheldon Brown's article explains how to do it. http://sheldonbrown.com/frame-spacing.html

Unless you have Suntour, upgrading groupos is not much of a problem. Most of the 7 sp front/rear derailleurs are easily workable with nine sp. STI. If you want more info on this do a search for some of Sheldon Brown's sites or ask on the rec.bicycle.tech newsgroup.

I plan on doing the exact same thing to my old Miele next winter. Upgrading a high quality classic frame is well worth the effort.

In upgrading my old steel road bike from 6-speed 105 to 9-speed 105, I honestly didn't even have to worry about spreading the rear. Depending on when the bike was actually made and by whom, your rear spacing may already by 130mm. Yeah, you need a new rear hub (I wanted new wheels anyway, so that wasn't a real issue).
The one thing that may jump out at you later is that you also [i]need[/i] a new chain. The old one should work for the majority of your bigger sprockets, but has a hard time fitting onto small, single-digit spaced ones (11t-14t). This may also translate to needing a new crankset, which is a decent chunk of change to add on top of new STI. You don't want to be riding along and have your chain jam in between your crankset wheels.
Your derailleurs will need adjusting, but they will both work fine with the added speeds...as long as the cage of your front der is wide enough to allow movement across 5-7 sprockets for each front chainring.

I researched this, haven't done it yet. This is what I learned. If you've got a steel frame, your local bike store can widen the rear triangle. It's not expensive - $20 or so. Definitely worth it to have it aligned correctly. You'll need a new rear hub, cassette and chain. Check around before changing your current shifters and deraileur. There's a good chance they'll work on the new setup.



Good luck.



Larry