8 Speed to 9 Speed

A.J.T.73 said:

I have a giant scr 3.0 and want to upgrade to 18 gears from 24. I have been doing alot of looking around and this is the set up i have come up with:

• Tiagra Double 4500 hollowtech II 9sp 170mm 39/52 no cups.
  
• Chain HG 73 9sp
  
• Tiagra 4500/4550 Hollowtech II british 68mm cups
  
• Scram Cassette PG950 9sp 11-26
  
• Tiagra 9sp Double 4500 front mech
  

Will this set up work and what else will i need. I know i need to change shifters.
Thanks
Alex

Funny, I was at a dealer yesterday talking about a customer who wanted to change from 16 to 24. You would need a new rear shifter to go from 8 to 9 cogs, not sure about the front.

A.J.T.73 said:

I have ......
Thanks
Alex

you need (obviously) the 9sp chain, cassette and shifters, but that's really all. I've had 8sp rear derailleurs work fine with 9sp stuff, and just about any old front "mech" (you must be a pom 🙂) will work, as should 8sp chainrings/cranks.

I have done a deal with my loacl bike shop, for a 18 speed set up and fitting.
This is what i get:

• 105 9sp shifters
  
• 105 front mech
  
• chain
  
• tiagra 9sp cassette 11-25
  
• 105 brakes
  
• Tiagra hollowtech 52/39 crank and bottom bracket
  

All with fitting for £205.
What you guys think?
thanks