Upgrading Componentry on a Road Bike

[iRide]

I have an ’09 Giant TCR Alliance and I’m hoping to slowly upgrade the componentry. Except for the breaks (Tektro TK-580 with P422 cartridge pads), cranks (FSA Gossamer MegaExo compact, 34/50), and bottom bracket (FSA Mega Exo, External) it’s fitted with Shimano 105 components.

I don’t want to spend crazy amounts of money for the lightest weight components but I’d like to know:

-Is there much of a difference in performance (other than the weight difference) between Shimano’s 105 and Ultegra componentry? What about between Ultegra and Dura-Ace (not the Di2)?

A friend of mine owns the local bike shop and he has some 105 brakes (they’re not the new 2011 ones) with about 300 miles on them and said that he’d take $65 for them...should I do it? Is there any reason why I should wait and get the new 105 brakes or Ulterga brakes?

I just started cycling early last year so I still have much to learn -- thanks for any help on this!

 

[jimboalee]

First things first.

Get wheels with MUCH LIGHTER rims. Get a pair of lighter tyres and tubes.

If you can, take 1/2 lb off each wheel and you will feel the difference. 1 lb off other bits won't feel much different.

 

[TheDoctor]

Jimbo is right - get better wheels and tyres.
105 is pretty good - you'd not lose much weight by going to Ultegra or Dura-ace, but it would cost a lot.
I'd also get some Koolstop brake pads on there, as the Tektro ones aren't great IMHO.

 

[Fab Foodie]

Beetr wheels and tyres first and formost as per Jim's post.

Small upgrades in componentry shaves grams and is barely noticeable in performance terms, wheels and tyres make a big difference. Worth saving some good cash for.

BTW it's 'brakes' for stopping as opposed to 'breaks'.

Cheers
FF.