Rob3rt
Man or Moose!
- Location
- Manchester
I got 105 on my Pinnacle and it don't feel and different to the Tiagravon my brothers Scott. Indeed, the brake calipers are identical, all bar the 105s having slightly darker paint.
The slant parallelogram geometry is the same, the cable movement ratio is the same, both hinge on fluorine treated pins. There really is no mechanical difference aside from the shifters and whatever brand of cable is used (and 105 now having concealed gear cables that can have a detrimental effect in shifting feel).
105 come with cartridge brake shoes, Tiagra brakes come with a disposable brakeblock/shoe combo (at least they did when it was still 9spd). Thus, off the shelf, 105 brakes are more convenient. You can change the brake shoe, but that is additional expense.