Originally Posted by
Saphod
I also think that upgrading the brakes would be beneficial (it's basically the final part I could think of that might make a noticeable change, I am happy with the rest). Since I am very new to bike mechanics and not very adept as of yet: Can someone please tell me what I would need to change if I also wanted to use BB7 brakes? Is the front and back brake the same (
http://www.wiggle.com.au/avid-bb7-mtb-disc-brake/)? Which rotor sizes front/rear do you recommend (frame size is 56)? Which rotor to go for? Do I need new pads? Can I stay with the Tiagra levers and cabling? And, and, and...
Since what I wrote above, I did put my BB7's on this bike. I went with Avid HS1 rotors, 180mm in front and 160mm in the rear. That's probably overkill, but I wouldn't say it's anywhere near "too much" braking power, so why not. I'm using Avid's organic brake pads to get less squeal in the rain. If you aren't worried about a little noise, the sintered pads last longer.
I believe the current generation of BB7's comes with G2 rotors and the sintered pads. There's really not a lot of reason not to use those to start with. You can always swap them out later if you aren't happy with them. You could also use the BB7's with the Tektro rotors that came with your bike, if you like them. A 160mm rotor will give you plenty of stopping power. Some people use 140mm in the rear (as the stock Jake did) to save weight since the stopping power there is less important and self-limiting. You can't go bigger than 160mm in the rear. A 180mm rotor in front will give you extra stopping power if you are a heavy rider or ride steep hills a lot.
I've probably confused you more with all the possibilities than I've helped. The bottom line is, as long as you are sure to get the road-specific BB7's you'll be fine with pretty much any combination. Your best bet is probably to just use the pads and rotors that come with the brakes.
They will work just fine with your Tiagra levers. There are adapters that you use to mount the brake to the bike. You need to match the adapter to the rotor size and the wheel position (front or rear), but the brake itself is the same either way. As I recall, the brakes come with adapters for front and rear. If not, your LBS probably has a bunch of them laying around.
I was able to swap from the stock Tektro brakes to BB7's without replacing the cables. I was willing to do that since I'm my own mechanic. Your LBS might want to replace the cable to be sure you get the best possible performance without having to come back for minor tweaks.
Speaking of best possible performance, remember that you'll need to bed the brakes in before they start performing at their best.
Edit: I just notice you linked to the MTB version of the BB7's. Those won't work for you. You need these:
http://www.wiggle.com.au/avid-avid-bb7-road-disc-brake/ Wiggle only lists rear brakes as being available, but as I said the same brake with a different adapter will work in front. You might want to check with the retailer to make sure you're going to get the right adapter.