Replacing cassette & chain.

[jayonabike]

Is it wise to replace these both at the same time? I will need to replace the chain on my Tiagra equipped bike soon. Would this chain and this cassette be the ideal replacment parts. I noticed this Ultegra 9 speed cassette. Would this make a great difference and be a good upgrade, or a waste of the extra cash?

 

[Alembicbassman]

If the teeth look worn replace both. Steel cassettes are pretty tough and will last several chains, depends how long you've run a worn chain on the cassette. 9 speed cassettes start at about £20, not really worth having an Ultegra one. http://www.chainreactioncycles.com/Models.aspx?ModelID=17902 Matched with a SRAM chain will give a quiet and smooth drivetrain.