Bicycle Mechanics - cassette question

I have a Cannondale R1000 that is in need of a new chain and cassette. Can I swap out the 8-spd cassette with a 9-spd cassette? Will any other mods be necessary to make the swap?

Thanks.

are the shifters and derailleurs 9 speed compatible?

Only if the shifters are 9 speed compatable.

Only if the shifters are 9 speed compatable.
Thanks. The shifters are 8-speed... Looks like I need to find an 8-spd cassette.

There should be plenty of 8speed cassettes( and chains) around and they will be cheaper than most of the nine speed stuff.

I'm running 12-23 now. What do I gain or lose with 13-26?

With 13/26 you'll have a much smaller climbing gear, so if you find hills a stuggle, it's a good idea. However, you will lose a bit of top speed (but if you're like me and never get into the 12 this isn't a problem :) ).

With 13/26 you'll have a much smaller climbing gear, so if you find hills a stuggle, it's a good idea. However, you will lose a bit of top speed (but if you're like me and never get into the 12 this isn't a problem :) ).

With 13/26 how do lose both the climbing gear and top speed? With a 26 don't I get more efficiency on hills?

Let's face it, I've got a Ferrari bike and a Corolla motor. At 200lbs., everything seems like a hill. I'm trying to find gears that make me as efficient as possible. High-speed racing isn't in the picture right now.

Can a 12/23 be replaced by a 13/26 or is there something more I need to be aware of?

Sorry to seem like such a moron. I just don't want to screw up my bike.

You'll also need a 9-speed chain.

You'll also need a 9-speed chain.

Oops. Forget to mention that after reading all these replies I think I'll stick with the 8-speed cassette. I've seen Ultegra's on eBay that are reasonably priced (compared to a full swap to 9-speed).

Thanks all.

I think by smaller he meant lower. The 13-26 will give you an easier climbing gear and a slightly lower top gear.

Smaller gear=shorter gear inch=easier to climb/pedal