I have a 2006 LeMond Etape that has an unnamed (I'm guessing Sora) 8-speed 11-26 cassette on it. My rear derailleur is a 9-speed Tiagra, so I was thinking about upgrading the bike with a 6500 9-speed cassette and a 9-speed brifter. I'm guessing I might have to get a slightly narrower chain as well... my question is, will a 9-speed cassette fit on my rear hub?
2003 Specialized Hardrock, 2004 LOOK KG386i, 2005 Iron Horse Warrior Expert, 2009 Pedal Force CX1
The cassette will fit the hub no problem. You will need a 9 speed chain as well. Are you aware of the cost of a 9 speed brifter? They can be purchased individually at least for some cost savings but the price of a new shifter might make this upgrade a no-go. My opinion is don't bother FWIW.
The 9 speed cassette will work just fine. Yes, you'll need a 9 speed chain as well. Rear derailleurs do not have speeds, so no worries there. With 8 speed cranks and a 9 speed chain you might have slightly slower shifting up front.
I have an Ultegra 9 speed 12-27 cassette with about 75 miles on it if you are interested. I bought a set of wheels along with this cassette for my BD bike this Christmas and later decided to build a steel bike with a 10 speed drivetrain and put these wheels on it so I have no use for the 9 speed cassette.